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Chiropractic: A Critical Evaluation

  • Edzard Ernst
    Correspondence
    Address correspondence to: Edzard Ernst, MD, PhD, FRCP, FRCPEd Complementary Medicine, Peninsula Medical School, Universities of Exeter and Plymouth, 25 Victoria Park Road, Exeter EX2 4NT, UK.
    Affiliations
    Complementary Medicine, Peninsula Medical School, Universities of Exeter & Plymouth, Exeter, United Kingdom
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Open AccessPublished:February 15, 2008DOI:https://doi.org/10.1016/j.jpainsymman.2007.07.004

      Abstract

      Chiropractic was defined by D.D. Palmer as “a science of healing without drugs.” About 60,000 chiropractors currently practice in North America, and, worldwide, billions are spent each year for their services. This article attempts to critically evaluate chiropractic. The specific topics include the history of chiropractic; the internal conflicts within the profession; the concepts of chiropractic, particularly those of subluxation and spinal manipulation; chiropractic practice and research; and the efficacy, safety, and cost of chiropractic. A narrative review of selected articles from the published chiropractic literature was performed. For the assessment of efficacy, safety, and cost, the evaluation relied on previously published systematic reviews. Chiropractic is rooted in mystical concepts. This led to an internal conflict within the chiropractic profession, which continues today. Currently, there are two types of chiropractors: those religiously adhering to the gospel of its founding fathers and those open to change. The core concepts of chiropractic, subluxation and spinal manipulation, are not based on sound science. Back and neck pain are the domains of chiropractic but many chiropractors treat conditions other than musculoskeletal problems. With the possible exception of back pain, chiropractic spinal manipulation has not been shown to be effective for any medical condition. Manipulation is associated with frequent mild adverse effects and with serious complications of unknown incidence. Its cost-effectiveness has not been demonstrated beyond reasonable doubt. The concepts of chiropractic are not based on solid science and its therapeutic value has not been demonstrated beyond reasonable doubt.

      Key Words

      Introduction

      Chiropractic is a popular form of health care for which many definitions can be found
      • Segen J.C.
      Dictionary of alternative medicine.
      • Oths K.
      Communication in a chiropractic clinic: how a D.C. treats his patients.
      • Lott C.M.
      Integration of chiropractic in the Armed Forces health care system.
      • Bimonte H.A.
      Laboratory testing in chiropractic practice.
      • Shekelle P.G.
      What role for chiropractic in healthcare?.
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      World Federation of Chiropractic.

      British Chiropractic Association. Chiropractic…a helping hand for you and your patients. Undated brochure. 2003.

      • American Chiropractic Association
      • Sportelli D.C.
      A natural method of health care.
      • Hadler N.M.
      Chiropractic.

      National Center for Complementary and Alternative Medicine. About chiropractic and its use in treating low-back pain. Accessed April, 2006. www.nccam.nih.gov/health/chiropractic/index.htm.

      (Table 1). “The ‘raison d'être’ of the chiropractic profession is the detection and correction of spinal subluxations.”
      • Redwood D.
      Chiropractic.
      In the “earliest known” publication
      • Keating J.C.J.
      • Green B.N.
      • Johnson C.D.
      “Research” and “science” in the first half of the chiropractic century.
      on the subject, its founder (Daniel David Palmer) stated that, “chiropractic is a science of healing without drugs.”
      • Palmer D.D.
      The chiropractic.
      Table 1Recent Definitions of Chiropractic
      DateDefinition/description (quotes)Source (Ref.)
      1998A system of healthcare…which is based on the belief that the nervous system is the most important determinant of a person's state of health.Segen
      • Segen J.C.
      Dictionary of alternative medicine.
      1994A drugless, non-invasive manual form of outpatient treatment for musculoskeletal, functional and other chronic disorders.Oths
      • Oths K.
      Communication in a chiropractic clinic: how a D.C. treats his patients.
      1996A therapeutic system based on the premise that structure and function in the human body are closely related and, in particular, the relationship between the spinal column and the nervous system is the most important.Lott
      • Lott C.M.
      Integration of chiropractic in the Armed Forces health care system.
      1998A system of healing based on the belief that health is maintained when the spinal column is in its proper position and the nervous system is not impinged.Bimonte
      • Bimonte H.A.
      Laboratory testing in chiropractic practice.
      1998Chiropractic…is based on the body's ability to heal itself. Central to improving the body's ability to heal itself, chiropractors assert, is the removal, or correction, of malalignments of the spine (called subluxations) through the use of spinal manipulation (called spinal adjustments).Shekelle
      • Shekelle P.G.
      What role for chiropractic in healthcare?.
      1998The medical profession that specializes in manual therapy and especially spinal manipulation.Kaptchuk
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      1999A health profession concerned with the diagnosis, treatment and prevention of mechanical disorders of the musculoskeletal system and the effects of these disorders on the function of the nervous system and general health. There is an emphasis on manual treatments, including spinal manipulation or adjustment.World Federation of Chiropractic
      World Federation of Chiropractic.
      1999A profession which specializes in the diagnosis, treatment and overall management of conditions which are due to mechanical dysfunction of the joints, particularly those of the spine, and their effects on the nervous system.British Chiropractic Association

      British Chiropractic Association. Chiropractic…a helping hand for you and your patients. Undated brochure. 2003.

      1999A branch of the healing arts which is concerned with human health and disease processes.American Chiropractic Association
      • American Chiropractic Association
      2000A branch of the healing arts…based on the premise that good health depends, in part, upon a normally functioning nervous system.Sportelli
      • Sportelli D.C.
      A natural method of health care.
      2000The chiropractic is not a technique. It is a health care profession, it has an exclusive body of information which teaches, certifies, policies, purveys and sometimes attempts to validate.Halder
      • Hadler N.M.
      Chiropractic.
      2003A form of health care that focuses on the relationship between the body's structure, primarily of the spine and function.NCCAM

      National Center for Complementary and Alternative Medicine. About chiropractic and its use in treating low-back pain. Accessed April, 2006. www.nccam.nih.gov/health/chiropractic/index.htm.

      Today, some chiropractors view chiropractic as an “alternative form of healthcare,”
      • Gay R.E.
      Chiropractic.
      but in most countries, chiropractic is seen as an adjunct to rather than a replacement of conventional medicine. Chiropractors have legal recognition in about half of the world, whereas in the other half, such recognition is lacking. In India, China, former Russia, parts of Europe, and most of South Africa,
      • Ong C.K.
      • Bodeker G.
      • Grundy C.
      • Burford G.
      • Shein K.
      WHO global atlas of traditional, complementary and alternative medicine.
      chiropractic is not legally recognized.
      In the United States, between $2.4 and $4.0 billion is spent each year on chiropractic care.
      • Shekelle P.G.
      The use and costs of chiropractic care in the health insurance experiment.
      • Stano M.
      The chiropractic services market: a literature review.
      Chiropractic is covered by Medicare, a substantial proportion of private and public insurance plans, all state-workers compensation systems, all forms of managed care, most health maintenance organizations, and private health insurance plans.
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      All 50 U.S. states, Puerto Rico, the District of Columbia, and the Virgin Islands license chiropractors.
      • Lott C.M.
      Integration of chiropractic in the Armed Forces health care system.
      • Dagenais S.
      • Haldeman S.
      Chiropractic.
      About 60,000 chiropractors currently practice in North America, a number that has tripled between 1970 and 1990.
      • Gay R.E.
      Chiropractic.
      • Coulter I.D.
      • Hurwitz E.L.
      • Adams A.H.
      • et al.
      Patients using chiropractors in North America.
      The proportion of the population using chiropractic services has doubled in the last two decades.
      • Coulter I.D.
      • Hurwitz E.L.
      • Adams A.H.
      • et al.
      Patients using chiropractors in North America.
      The chiropractic profession is thus growing rapidly; more than 4,000 students graduate each year from about 30 chiropractic colleges in the United States, and the total number of U.S. chiropractors is predicted to reach 100,000 by 2010.
      Foundation for the Advancement of Chiropractic, Tenets and Sciences.
      • Cooper R.A.
      • Stoflet S.J.
      Trends in the education and practice of alternative medicine clinicians.
      This article critically analyzes the history, rationale, and practice of chiropractic. It asks the question: Does chiropractic generate more good than harm? It draws mainly on the published chiropractic literature, including several articles that have previously reviewed chiropractic.
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      • Sportelli D.C.
      A natural method of health care.
      • Hadler N.M.
      Chiropractic.
      The scarcity of critical in-depth analyses is noted; its implications are described.

      History

      The history of chiropractic is “rooted in quasi-mystical concepts.”
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      Bonesetters of various types are part of the folk medicine of most cultures,
      • Cooter R.
      Bones of contention? Orthodox medicine and the mystery of the bone-setter's craft.
      • LeVay D.
      British bone-setters.
      • Papet J.
      Cases that bonesetters cure.
      and bonesetting also formed the basis on which chiropractic developed. The birthday of chiropractic is said to be September 18, 1895. On this day, D.D. Palmer manipulated the spine of a deaf janitor by the name of Harvey Lillard, allegedly curing him of his deafness.
      • Wardwell W.
      Chiropractic: History and evolution of a new profession.
      Palmer's second patient, a man suffering from heart disease, was also cured.
      • DeVocht J.W.
      History and overview of theories and methods of chiropractic: a counterpoint.
      About one year later, Palmer opened the first school of chiropractic.
      • DeVocht J.W.
      History and overview of theories and methods of chiropractic: a counterpoint.
      There is evidence to suggest that D.D. Palmer had learned manipulative techniques from Andrew Taylor Still (1828–1917), the founder of osteopathy.
      • Baer H.A.
      The drive for legitimation by osteopathy and chiropractic in Australia: between hetrodoxy and orthodoxy.
      He combined the skills of a bonesetter with the background of a magnetic healer and claimed that “chiropractic was not evolved from medicine or any other method, except that of magnetic.”
      • Palmer D.D.
      Textbook of the art, science and philosophy of chiropractic.
      He coined the term “innate intelligence” (or “innate”) for the assumed “energy” or “vital force,” which, according to the magnetic healers of that time, enables the body to heal itself. The “innate” defies quantification. “Chiropractic is based on a metaphysical epistemology that is not amenable to positivist research or experiment.”
      • Villanueva-Russell Y.
      Evidence-based medicine and its implications for the profession of chiropractic.
      The “innate” is said to regulate all body functions but, in the presence of “vertebral subluxation,” it cannot function adequately. Chiropractors therefore developed spinal manipulations to correct such subluxations, which, in their view, block the flow of the “innate.”
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      Chiropractic is “a system of healing based on the premise that the body requires unobstructed flow through the nervous system of…innate intelligence.”
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.
      Anyone who did not believe in the “innate” or in “subluxations” was said to have no legitimate role in chiropractic.

      Gold R. Presentation at the Los Angeles College of Chiropractic, November 18, 1994.

      “Innate intelligence” evolved as a theological concept, the representative of Universal Intelligence (=God) within each person.
      • Fuller R.C.
      Alternative medicine and American religious life.
      D.D. Palmer was convinced he had discovered a natural law that pertained to human health in the most general terms. Originally, manipulation was not a technique for treating spinal or musculoskeletal problems, it was a cure for all human illness: “95% of all diseases are caused by displaced vertebrae, the remainder by luxations of other joints.”
      • Homola S.
      Bonesetting, chiropractic and cultism.
      Early chiropractic pamphlets hardly mention back pain or neck pain, but assert that, “chiropractic could address ailments such as insanity, sexual dysfunction, measles and influenza.”
      • Palmer B.J.
      Chiropractic proofs.
      D.D. Palmer was convinced that he had “created a science of principles that has existed as long as the vertebra.”
      • Palmer D.D.
      The chiropractor's adjustor.
      Chiropractors envision man as a microcosm of the universe where “innate intelligence” determines human health as much as “universal intelligence” governs the cosmos; the discovery of the “innate intelligence” represents a discovery of the first order, “a reflection of a critical law that God used to govern natural phenomena.”
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.

      Chiropractic as a Religion

      Early chiropractic displayed many characteristics of a religion. Both D.D. Palmer and his son, B.J. Palmer, seriously considered establishing chiropractic as a religion.
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.
      Chiropractic “incorporated vitalistic concepts of an innate intelligence with religious concepts of universal intelligence,” which substituted for science.
      • Haldeman S.
      The evolution and importance of spinal and chiropractic research.
      D.D. Palmer declared that he had discovered the answer to the timeworn question, “What is life?” and added that chiropractic made “this stage of existence much more efficient in its preparation for the next step—the life beyond.”
      • Palmer D.D.
      The chiropractor's adjustor.
      Most early and many of today's chiropractors agree: “Men do not cure. It is that inherent power (derived from the creator) that causes wounds to heal, or a part to be repaired. The Creator…uses the chiropractor as a tool…chiropractic philosophy is truly the missing link between Religion or Power of the various religions.”
      • Keating J.C.J.
      • Cleveland C.S.
      Cleveland chiropractic: the early years, 1917–1933.
      Today, some chiropractors continue to relate the “innate” to God.
      • Strauss J.B.
      Refined by fire: the evolution of straight chiropractic.
      Others, however, warn not to “dwindle or dwarf chiropractic by making a religion out of a technique.”
      • Beideman R.P.
      Seeking the rational alternative: the National College of Chiropractic from 1906 to 1982.

      External Conflict

      Initially, the success of chiropractic was considerable. By 1925, more than 80 chiropractic schools had been established in the United States. Most were “diploma mills” offering an “easy way to make money,”
      • DeVocht J.W.
      History and overview of theories and methods of chiropractic: a counterpoint.
      and many “were at one another's throats.”
      • Keating J.C.J.
      • Cleveland C.S.
      Cleveland chiropractic: the early years, 1917–1933.
      Chiropractors believed they had established their own form of science,
      • Palmer D.D.
      The science of chiropractic: Its principles and adjustments.
      which emphasized observation rather than experimentation, a vitalistic rather than mechanistic philosophy, and a mutually supportive rather than antagonist relationship between science and religion. The gap between conventional medicine and chiropractic thus widened “from a fissure into a canyon.”
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.
      The rivalry was not confined to conventional medicine; “many osteopaths asserted that chiropractic was a bastardized version of osteopathy.”
      • Baer H.A.
      The drive for legitimation by osteopathy and chiropractic in Australia: between hetrodoxy and orthodoxy.
      Rather than arguing over issues such as efficacy, education, or professional authority, the American Medical Association insisted that all competent health care providers must have adequate knowledge of the essential subjects such as anatomy, physiology, pathology, chemistry, and bacteriology.
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.
      By that token, the American Medical Association claimed, chiropractors were not fit for practice.
      • Wardwell W.
      Chiropractic: History and evolution of a new profession.
      Some “martyrs,” including D.D. Palmer himself, went to jail for practicing medicine without a licence.
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      • Keating J.C.J.
      • Cleveland C.S.
      Cleveland chiropractic: the early years, 1917–1933.
      Chiropractors countered that doctors were merely defending their patch for obvious financial reasons (ironically, chiropractors today often earn more than conventional doctors
      • Baer H.A.
      The drive for legitimation by osteopathy and chiropractic in Australia: between hetrodoxy and orthodoxy.
      ), that orthodox science was morally corrupt and lacked open-mindedness.
      • Martin S.C.
      “The only truly scientific method of healing” Chiropractic and American science. 1895–1990.
      They attacked the “germo-anti-toxins-vaxiradi-electro-microbio-slush death producers”
      • Palmer D.D.
      The science of chiropractic: Its principles and adjustments.
      and promised a medicine “destined to the grandest and greatest of this or any age.”
      • Palmer D.D.
      Textbook of the art, science and philosophy of chiropractic.
      Eventually, the escalating battle against the medical establishment was won in “the trial of the century.”
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      In 1987, sections of the U.S. medical establishment were found “guilty of conspiracy against chiropractors,”
      • Getzendanner S.
      Permanent injunction order against AMA.
      a decision which was upheld by the U.S. Supreme Court in 1990.
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      In other countries, similar legal battles were fought, usually with similar outcomes.
      • Dew K.
      Apostasy to orthodoxy: debates before a Commission of Inquiry into chiropractic.
      • O'Neill A.
      • Willis E.
      Chiropractic and the politics of health care.
      Only rarely did they not result in the defeat of the “establishment:” In 1990, a Japanese Ministry of Health report found that chiropractic is “not based on the knowledge of human anatomy but subjective and unscientific.”

      The Ministry of Health and Welfare of Japan. Health science research report on manipulative therapy for diseases of spinal origin. 1990.

      Internal Conflict

      These victories came at the price of “taming” and “medicalizing” chiropractic.
      • Dew K.
      Apostasy to orthodoxy: debates before a Commission of Inquiry into chiropractic.
      In turn, this formed the basis of a conflict within the chiropractic profession—the dispute between “mixers” and “straights”—a conflict which continues to the present day.
      The “straights” religiously adhere to D.D. Palmer's notions of the “innate intelligence” and view subluxation as the sole cause and manipulation as the sole cure of all human disease. They do not mix any nonchiropractic techniques into their therapeutic repertoire, dismiss physical examination (beyond searching for subluxations) and think medical diagnosis is irrelevant for chiropractic.
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      The “mixers” are somewhat more open to science and conventional medicine, use treatments other than spinal manipulation, and tend to see chiropractors as back pain specialists.
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      • Wardwell W.
      Chiropractic: History and evolution of a new profession.
      Father and son Palmer warned that the “mixers” were “polluting and diluting the sacred teachings” of chiropractic.
      • Palmer D.D.
      The chiropractor's adjustor.
      Many chiropractors agreed that the mixers were “bringing discredit to the chiropractic.”
      • Keating J.C.J.
      • Cleveland C.S.
      Cleveland chiropractic: the early years, 1917–1933.
      The “straights” are now in the minority but nevertheless exert an important influence. They have, for instance, recently achieved election victories within the British General Chiropractic Council.

      Wight CJK. Elections in the UK. The chiropractic choice 2002;Sept:18.

      Today, two different chiropractic professions exist side by side—“one that wishes to preserve the non-empirical, non-positivist, vitalist foundations (the straights) and the other that wishes to be reckoned as medical physicians and wishes to utilize the techniques and mechanistic viewpoint of orthodox medicine (the mixers).”
      • Villanueva-Russell Y.
      Evidence-based medicine and its implications for the profession of chiropractic.
      The International Chiropractic Association represents the “straights” and the American Chiropractic Association the “mixers.”

      Core Concepts

      The three main hypotheses of modern chiropractic have been summarized as follows:
      • Gay R.E.
      Chiropractic.
      • There is a functional relationship between the spine and health mediated through the nervous system.
      • Subluxations adversely affect health.
      • Correction of subluxation by spinal manipulation improves or restores health.
      “Give me a simple mind that thinks along single tracts, give me 30 days to instruct him, and that individual can go forth on the highways and byways and get more sick people well than the best, most complete, all around, unlimited medical education of any medical man who ever lived.”
      • Palmer B.J.
      Palmer tells benefits of advertising.
      This remark by B.J. Palmer implies that naivety is required to accept the implausibility of the chiropractic concepts. The founders of chiropractic created myths and denied scientific discoveries; B.J. Palmer, for instance, rejected the existence of the sympathetic nervous system,
      • Keating J.C.J.
      • Green B.N.
      • Johnson C.D.
      “Research” and “science” in the first half of the chiropractic century.
      and early chiropractors denied the existence of the germ theory of disease, which has important implications for public health today (see below).
      The “mixers,” however, saw the insistence on the “innate” as “religious baggage.”
      • Waagen G.
      Origin and development of traditional chiropractic philosophy.
      Today many chiropractors are anxious to sever all links with this concept,
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      fearing that it might jeopardize chiropractics' acceptance into the mainstream.
      • Winterstein J.F.
      Is traditional “chiropractic philosophy” valid today?.
      • DeBoer K.F.
      Commentary: eine kleine nacht musing.
      • Homola S.
      Chiropractic: history and overview of theories and methods.

      Subluxation

      Some chiropractors prefer terminology such as “vertebral subluxation complex,”
      • Lantz C.A.
      The vertebral subluxation complex, I: Introduction to the model and the kinesiological component.
      “manipulable spinal lesion,”
      • Haldeman S.
      Spinal manipulation therapy: a status report.
      “chiropractic lesion,”
      • Keating J.C.J.
      Shades of straight: diversity among the purists.
      or “vertebral blockage,”
      • Lewit K.
      Manipulative therapy and rehabilitation of the locomotor system.
      yet most modern chiropractors accept the concept of subluxation.
      • Redwood D.
      Chiropractic.
      The term as used in chiropractic means something different from subluxation in regular medicine. Here, I refer to the term as used in chiropractic. For D.D. Palmer, it was “a static malalignment of a single vertebra.”
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      Subluxations are believed to impinge on spinal nerves, therefore blocking the flow of the “innate intelligence” (according to “straights”) or causing disease in some other way (according to “mixers”).
      Many “straights” adhere to B.J. Palmer's theory that atlas subluxations impinge on the spinal cord;
      • Haldeman S.
      The evolution and importance of spinal and chiropractic research.
      “chiropractic gets sick people well by adjusting vertebral subluxations of atlas and axis only.”

      Palmer BJ, Shermann LW, Coulter WW. Hematological changes under specific chiropractic adjustment: research on 1054 cases in the B.J. Palmer Chiropractic Clinic. Number 1 in a series of scientific laboratory experiments proving the effectiveness of specific chiropractic technic. Davenport,IA: Palmer School of Chiropractic, undated (c. 1949).

      This “narrowed the search for specific causes of patients' maladies by narrowing the area of the search to the upper spine.”
      • Keating J.C.J.
      • Green B.N.
      • Johnson C.D.
      “Research” and “science” in the first half of the chiropractic century.
      Until recently, such chiropractic theories were left unquestioned and untested.
      • Johnson C.
      Editorial: modernized chiropractic reconsidered: beyond foot-on-hose and bones-out-of-place.
      Chiropractic was (and arguably is) a matter of belief rather than evidence.
      Several theories have been advanced to explain how subluxations might cause health problems,
      • Triano J.J.
      Biomechanics of spinal manipulative therapy.
      • Drake J.D.
      • Aultman C.D.
      • McGill S.M.
      • Callaghan J.P.
      The influence of static axial torque in combined loading on intervertebral joint failure mechanics using a porchine model.
      • Vera-Garcia F.J.
      • Brown S.H.
      • Gray J.R.M.S.M.
      Effects of different levels of torso coactivation on trunk muscular and kinematic responses to posteriorly applied sudden loads.
      for example, through edema around intervertebral foramina
      • Lantz C.A.
      Inflammation hypothesis.
      or twisting the dura mater.
      • Grostic J.D.
      Dentate ligament: cord distortion hypothesis.
      However, none of these have been independently confirmed and the specific mechanisms involved are not known.
      • DeVocht J.W.
      History and overview of theories and methods of chiropractic: a counterpoint.
      • Henderson W.
      CNR: animal models in the study of subluxation and manipulation: 1964–2004.
      In fact, subluxations have never been proven to constitute a relevant entity. Critics have repeatedly pointed out that even severe nerve root compression does not cause organic disease.
      • Crelin E.S.
      A scientific test of the chiropractic theory.
      College of Physicians and Surgeons of the Province of Quebec. A scientific brief against chiropractic.
      • Nansel D.
      • Szlazak M.
      Somatic dysfunction and the phenomenon of visceral disease simulation: a probable explanation for the apparent effectiveness of somatic therapy in patients presumed to be suffering from true visceral disease.
      Regardless of such doubts, the U.S. Association of Chiropractic Colleges reached a consensus in 1996 that “chiropractic is concerned with the preservation and restoration of health and focuses particular attention on the subluxation. A subluxation is a complex of functional and/or pathological articular changes that compromise neural integrity and may influence organ systems function and general health.”
      • Association of Chiropractic Colleges
      A position paper on chiropractic.
      One year later, the U.S. Foundation for Chiropractic Education and Research published a monograph stating that subluxation “embraces the holistic nature of the human body, including health, well-being, the doctor/patient relationship, and the changes in the nerve, muscle, connective tissue, and vascular tissues which are understood to accompany the kinesiologic aberrations of spinal articulations.”
      • Rosner A.
      The role of subluxation in chiropractic.
      Today, 88% of U.S. chiropractors believe that subluxation contributes to over 60% of all visceral ailments and 90% think it should, therefore, not be limited to muskuloskeletal conditions.
      • McDonald W.
      • Durkin K.
      • Iseman S.
      • et al.
      How chiropractors think and practice.
      In other countries, for example, Canada, these percentage figures are usually lower.
      • Biggs L.
      • Hay D.
      • Mierau D.
      Canadian chiropractors' attitudes towards chiropractic philosphy and scope of practice: implcations for the implementation of clinical practice guidelines.

      Spinal Manipulation

      Subluxations can be corrected with spinal manipulations or “adjustments,” a term preferred by some chiropractors.
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      Today most chiropractors agree with D.D. Palmer that spinal manipulation has to be specific, that is, at the correct spinal segment.
      • O'Malley J.N.
      How real is the subluxation?.
      There is, however, less agreement on the optimal direction or the level of manipulation.
      • Mootz R.D.
      • Keating Jr., J.C.
      • Kontz H.P.
      • Milus T.B.
      • Jacobs G.E.
      Intra- and interobserver reliability of passive motion palpation of the lumbar spine.
      • Nansel D.D.
      • Peneff A.L.
      • Jansen R.D.
      • Cooperstein R.
      Interexaminer concordance in detecting joint-play asymmetries in the cervical spines of otherwise asymptomatic subjects.
      Chiropractors even disagree about the term spinal manipulation.
      • Walker B.F.
      • Buchbinder R.
      Most commonly used methods of detecting spinal subluxation and the preferred term for its description: a survey of chiropractors in Victoria, Australia.
      • Vernon H.
      • Mrozek J.
      A revised definition of manipulation.
      In its broadest definition, it describes the “application of a load (force) to specific body or tissues with therapeutic intent.”
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      Spinal manipulation moves vertebrae beyond their physiological range of motion (chiropractors speak of “end feel” and “paraphysiological space”)
      • Redwood D.
      Chiropractic.
      but not far enough to destroy joint structures:
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.
      “between the normal range of motion and the limits of its normal integrity.”
      • Redwood D.
      Chiropractic.
      Chiropractors believe that spinal manipulation breaks fibrous adhesions within joints, or that it “releases small tags from the joint capsule that might be entrapped within the joint,” or that it affects the mechanoreceptors of the joint, or that it modulates central nervous system excitability,
      • Dagenais S.
      • Haldeman S.
      Chiropractic.
      or that it inhibits C-fiber mediated pain perception.
      • George S.Z.
      • Bishop M.D.
      • Bialosky J.E.
      • Zeppieri Jr., G.
      • Robinson M.E.
      Immediate effects of spinal manipulation on thermal pain sensitivity: an experimental study.
      None of these theories are, however, supported by sound evidence.
      • Keating Jr., J.C.
      • Charlton K.H.
      • Grod J.P.
      • et al.
      Subluxation: dogma or science?.
      Numerous forms of spinal manipulation exist but “the short-lever technique—touching the vertebrae directly at high velocity and low amplitude, i.e., by moving a small distance—with the spinal or transverse process as a fulcrum, is considered the typical chiropractic manoeuver.”
      • Kaptchuk T.J.
      • Eisenberg D.M.
      Chiropractic: origins, controversies, and contributions.

      Chiropractic Practice

      The Profession(s)

      Many chiropractors (mixers) view themselves as primary care providers
      • Baer H.A.
      The drive for legitimation by osteopathy and chiropractic in Australia: between hetrodoxy and orthodoxy.
      • Barnett K.
      • McLachlan C.
      • Hulbert J.
      • Kassak K.
      Working together in rural South Dakota: integrating medical and chiropractic primary care.
      or general practitioners with “an important role in health promotion and injury or disease prevention.”
      • Killinger L.Z.
      Chiropractic and geriatrics: a review of the training, role, and scope of chiropractic in caring for aging patients.
      • Evans M.W.J.
      • Rupert R.
      The Council on Chiropractic Education's new wellness standard: a call to action for the chiropractic profession.
      “Integrative medicine” is often seen as “the next step in gaining access to patients.”
      • Menke J.M.
      Principles in integrative chiropractic.
      Overall, estimates of the use of chiropractic services by the general population range from 3% to 18%.
      • Dagenais S.
      • Haldeman S.
      Chiropractic.
      Health care professionals usually prefer other forms of complementary/alternative medicine to chiropractic.
      • Freymann H.
      • Rennie T.
      • Bates I.
      • Nebel S.
      • Heinrich M.
      Knowledge and use of complementary and alternative medicine among British undergraduate pharmacy students.
      • Torkelson C.
      • Harris I.
      • Kreitzer M.J.
      Evaluation of a complementary and alternative medicine rotation in medical school.
      Chiropractors predominantly treat patients with musculoskeletal problems, about 60% of whom suffer from low back pain. In the United States, 13% of all back pain sufferers consult a chiropractor.
      • Carey T.S.
      • Evans A.T.
      • Halder N.M.
      • et al.
      Acute severe low back pain. A population based study of prevalence and care seeking.
      Another domain is neck pain, which chiropractors usually treat with upper spinal manipulation. One report indicates, however, that only 11% of all cervical manipulations are “appropriate.”
      • Coulter I.
      • Hurwitz E.
      • Adams A.
      • et al.
      The appropriateness of manipulation and mobilization of the cervical spine.
      Spinal manipulation is also practiced in other professions (e.g., osteopaths, physiotherapists, and doctors) but chiropractors deliver more than 90% of all spinal manipulations.
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      Treatment is often continued for over three months, even in the absence of clinical improvement.
      • Pincus T.
      • Vogel S.
      • Breen A.
      • Foster N.
      • Underwood M.
      Persistent back pain—why do physical therapy clinicians continue treatment? A mixed methods study of chiropractors, osteopaths and physiotherapists.
      Consultations last for an average of 22 minutes.
      • Yeh G.Y.
      • Phillips R.S.
      • Davis R.B.
      • Eisenberg D.M.
      • Cherkin D.C.
      Visit time as a framework for reimbursement: time spent with chiropractors and acupuncturists.
      Many U.S. chiropractors use “practice building seminars” (often organized by Scientologists) to convince their patients of the value of their treatments.
      • Baer H.A.
      Practice-building seminars in chiropractic: a Petit Bourgeois response to biomedical domination.
      Chiropractors work mostly in single practices (67%) and have an average of 3.8 years of basic training.
      • Yeh G.Y.
      • Phillips R.S.
      • Davis R.B.
      • Eisenberg D.M.
      • Cherkin D.C.
      Visit time as a framework for reimbursement: time spent with chiropractors and acupuncturists.
      Their income frequently exceeds that of conventional primary care physicians.
      • Baer H.A.
      The drive for legitimation by osteopathy and chiropractic in Australia: between hetrodoxy and orthodoxy.

      The Treatments

      In addition to spinal manipulations, “mixers” also use other modalities such as heat, cold, and electrotherapy; they also may advise on supplement usage, lifestyle, weight loss, or relaxation.
      • Meeker W.C.
      • Haldeman S.
      Chiropractic: a profession at the crossroads of mainstream and alternative medicine.
      Maintenance chiropractic care is promoted as a preventative measure for both musculoskeletal and visceral problems
      • Rupert R.L.
      A survey of practice patterns and the health promotion and prevention attitudes of US chiropractors. Maintenance care: part I.
      even though “such unnecessary manipulation might present a risk to patients.”
      • Homola S.
      Seeking a common denominator in the use of spinal manipulation.
      Some chiropractors refer patients to homeopaths, iridologists, or paranormal healers.
      • Assendelft W.J.J.
      • Pfeifle C.
      • Bouter L.M.
      Chiropractic in the Netherlands: a survey of Dutch chiropractors.
      Many chiropractors use unproven or disproven methods themselves such as homeopathy (46%), applied kinesiology (38%),
      • Christensen M.
      • Kollasch M.
      • Ward R.
      • et al.
      Job analysis of chiropractic.
      or traction.
      • Assendelft W.J.J.
      • Pfeifle C.
      • Bouter L.M.
      Chiropractic in the Netherlands: a survey of Dutch chiropractors.
      In fact, applied kinesiology is rated to be among their most reliable diagnostic methods.
      • Walker B.F.
      • Buchbinder R.
      Most commonly used methods of detecting spinal subluxation and the preferred term for its description: a survey of chiropractors in Victoria, Australia.
      “Widespread unjustified claims which chiropractors routinely make” have become a concern even for some chiropractors.
      • Keating J.C.J.
      • Hansen D.T.
      Quackery vs. accountability in the marketing of chiropractic.
      A comparison of practice guidelines issued by various chiropractic organizations disclosed “discrepancies in the strength of recommendations, the type of recommendations and even the evidence upon which the recommendations have been based.”
      • Villanueva-Russell Y.
      Evidence-based medicine and its implications for the profession of chiropractic.

      Patients

      About 90% of chiropractic patients are self-referred,
      • Menke J.M.
      Principles in integrative chiropractic.
      and payment often comes (35%) directly from the patient.
      • Yeh G.Y.
      • Phillips R.S.
      • Davis R.B.
      • Eisenberg D.M.
      • Cherkin D.C.
      Visit time as a framework for reimbursement: time spent with chiropractors and acupuncturists.
      Chiropractic patients are more likely than medical patients to be obese, lack a regular doctor, have few chronic conditions, take few drugs, and be uninsured and dissatisfied with health care.
      • Hurwitz E.L.
      • Chiang L.M.
      A comparative analysis of chiropractic and general practitioner patients in North America: findings from the joint Canada/United States Survey of Health, 2002–03.
      A sizable proportion of U.S. chiropractic patients (20%–30%) receive in excess of 11 treatments sessions.
      • Barnett K.
      • McLachlan C.
      • Hulbert J.
      • Kassak K.
      Working together in rural South Dakota: integrating medical and chiropractic primary care.
      For neck pain, an average number of 25 visits was recently reported, and 2% of these patients received more than 80 treatment sessions.
      • Haneline M.T.
      Symptomatic outcomes and perceived satisfaction level of chiropractic patients with a primary diagnosis involving acute neck pain.
      In other countries, for example, Canada, these percentages may be considerably lower.
      • Waalen D.P.
      • White T.P.
      • Waalen J.K.
      Demographic and clinical characteristics of chiropractic patients: a five year study of patients treated at the Canadian Memorial Chiropractic College.
      Reasons for patients not to consult chiropractors include the fear of adverse effects and “lack of scientific proof.”
      • Menke J.M.
      Principles in integrative chiropractic.
      In general, the public seems to prefer medical doctors as their primary care providers.
      • Teitelbaum M.
      The role of chiropractic in primary care: findings of four community studies.
      In some parts of Canada (British Columbia and Ontario), chiropractic services have recently been delisted, and the Ontario government estimated that $100 million will be saved through this move.
      • Dales J.
      Delisting chiropractic and physiotherapy: false saving?.

      Indications

      Chiropractic services are used mostly, but by no means exclusively, for the management of musculoskeletal conditions. The American Chiropractic Association stresses, however, that chiropractic care is “not limited to back pain, neck pain” or other neuromusculoskeletal disorders;
      • American Chiropractic Association
      11%–19% of all chiropractic patients suffer from nonmusculoskeletal conditions.
      • Plamondon R.L.
      Summary of 1994 ACA Annual Statistical Study.
      • Phillips R.B.
      A survey of Utah chiropractic patients.
      This figure seems to be considerably lower outside the United States.
      • Assendelft W.J.J.
      • Pfeifle C.
      • Bouter L.M.
      Chiropractic in the Netherlands: a survey of Dutch chiropractors.
      • Leboeuf-Yde C.
      • Hennius B.
      • Rudberg E.
      • Leufvenmark P.
      • Thunman M.
      Chiropractic in Sweden: a short description of patients and treatment.
      Most chiropractic texts discuss spinal manipulation as a treatment for visceral disorders,
      • Redwood D.
      Chiropractic.
      • Gay R.E.
      Chiropractic.
      • Wiles M.R.
      Visceral disorders related to the spine.
      • Swenson R.S.
      Clinical investigation of reflex function.
      and it has been noted that, “there have been over 1,200 published studies linking spinal trauma to visceral disease.”
      • Faridi T.J.
      • Ponsonby D.P.
      Spinal manipulation and visceral disease: science rediscovers an ancient art.
      Nonmusculoskeletal problems regularly treated by chiropractors include respiratory conditions, nonspinal injuries, digestive system disorders, menstrual problems, ear infections, pregnancy-related conditions, infectious and parasitic conditions, dermatological diseases, and acute urinary conditions.
      • Barnett K.
      • McLachlan C.
      • Hulbert J.
      • Kassak K.
      Working together in rural South Dakota: integrating medical and chiropractic primary care.
      Chiropractors cite uncontrolled studies in support of spinal manipulations for indications such as dysmenorrhea, asthma, otitis media, hypertension, IBS, and peptic disorders.
      • Gorman R.F.
      The treatment of presumptive optic nerve ischemia by spinal manipulation.
      • Froehle R.M.
      Ear infection: a retrospective study examining improvement from chiropractic care and analyzing for influencing factors.
      • Stude D.E.
      • Bergmann T.F.
      • Finer B.A.
      A conservative approach for a patient with traumatically induced urinary incontinence.
      • Keating J.C.
      Chiropractic management of primary nocturnal enuresis.
      • Sawyer C.
      • Haas M.
      • Nelson C.
      • Elkington W.
      Clinical research within the chiropractic profession: status, needs and recommendations.
      The chiropractic literature is rife with claims related to nonspinal indications, for example, “the judicial use of chiropractic services in cancer patients appears to offer many economical and effective strategies for reducing the pain and suffering of cancer patients….”
      • Evans R.C.
      • Rosner A.L.
      Alternatives in cancer pain treatment: the application of chiropractic care.

      Diagnostics

      The reliability of diagnostic techniques used by chiropractors is generally poor.
      • Mootz R.D.
      • Keating Jr., J.C.
      • Kontz H.P.
      • Milus T.B.
      • Jacobs G.E.
      Intra- and interobserver reliability of passive motion palpation of the lumbar spine.
      • Troyanovich S.J.
      • Harrison D.D.
      • Harrison D.E.
      Motion palpation: it's time to accept the evidence.
      • Christensen H.W.
      • Vach W.
      • Vach K.
      • et al.
      Palpation of the upper thoracic spine: an observer reliability study.
      • French S.D.
      • Green S.
      • Forbes A.
      Reliability of chiropractic methods commonly used to detect manipulable lesions in patients with chronic low-back pain.
      • Hestbaek L.
      • Leboeuf-Yde C.
      Are chiropractic tests for the lumbo-pelvic spine reliable and valid? A systematic critical literature review.
      • Hawk C.
      • Phongphua C.
      • Bleecker J.
      • et al.
      Preliminary study of the reliability of assessment procedures for indications for chiropractic adjustments of the lumbar spine.
      • Maher C.
      • Adams R.
      Reliability of pain and stiffness assessments in clinical manual lumbar spine examination.
      • Panzer D.M.
      The reliability of lumbar motion palpation.
      • Haas M.
      • Peterson D.
      A roentgenological evaluation of the relationship between segmental motion and malalignment in lateral bending.
      Plain static radiograph and functional radiograph investigations are viewed as the most reliable methods for diagnosing subluxations.
      • Walker B.F.
      • Buchbinder R.
      Most commonly used methods of detecting spinal subluxation and the preferred term for its description: a survey of chiropractors in Victoria, Australia.
      Thus, practically all new (96.3%) and most continuing (80%) U.S. chiropractic patients undergo radiography, with an average number of views per new patient of 3.4.
      • Plamondon R.L.
      Summary of 1994 ACA Annual Statistical Study.
      Yet, guidelines state that a competent chiropractor “does not do routine radiographs on every patient.”
      • Curtis P.
      • Bove G.
      Family physicians, chiropractors, and back pain.
      The majority of U.S. chiropractors (86%) have their own X-ray equipment,
      • Plamondon R.L.
      Summary of 1994 ACA Annual Statistical Study.
      whereas elsewhere, for example, in Holland, this figure is lower (58%).
      • Assendelft W.J.J.
      • Pfeifle C.
      • Bouter L.M.
      Chiropractic in the Netherlands: a survey of Dutch chiropractors.
      Although most patients consulting a chiropractor have a radiograph taken,
      • Ernst E.
      Chiropractors' use of X-rays.
      only 4% of UK back pain patients in general practice have the procedure.
      • Scheurmier N.
      • Breen A.C.
      A pilot study of the purchase of manipulation services for acute low back pain in the United Kingdom.
      Most experts today caution that radiographic investigations for nonspecific back pain are frequently unnecessary
      • Refshauge K.M.
      • Maher C.G.
      Low back pain investigations and prognosis: a review.
      and harmful.
      • Herzog P.
      • Rieger C.T.
      Risk of cancer from diagnostic X-rays.
      Many U.S. chiropractors also do blood and urine analyses and some engage in minor surgery.
      • Barnett K.
      • McLachlan C.
      • Hulbert J.
      • Kassak K.
      Working together in rural South Dakota: integrating medical and chiropractic primary care.
      In Oregon, chiropractors are allowed to deliver babies,

      South Dakota Board of Chiropractic Examiners. Information Hotline, Vol. 1, Issue 6. Accessed May 7, 2007. Available at http://www.state.sd.us/doh/chiropractic/Publications/April2007.pdf.

      but in most U.S. states, obstetrics is specifically prohibited to them. Conventional U.S. doctors are unlikely to make formal referrals to chiropractors.
      • Greene B.R.
      • Smith M.
      • Allareddy V.
      • Haas M.
      Referral patterns and attitudes of primary care physicians towards chiropractors.

      Ethics

      A comparison of Californian disciplinary actions (1998–2002) against chiropractors and medical doctors showed that there were 4.5 such actions per 1,000 chiropractors per year, a figure which was 98% higher than that for doctors. The incidence rate per 1,000 for fraud was 1.99 for chiropractors, 895% higher than that for doctors. The incidence rate for sexual boundary transgressions was 1.01 for chiropractors, 339% higher than that for doctors.
      • Foreman S.M.
      • Stahl M.J.
      Chiropractors disciplined by a state chiropractic board and a comparison with disciplined medical physicians.
      Informed consent is a serious concern in chiropractic practice. Of 150 randomly selected UK chiropractors, only 23% reported always discussing serious risks with their patients before treatment, a behavior that clearly is in conflict with the UK ethical code.
      • Langworthy J.M.
      • le Fleming C.
      Consent or submission? The practice of consent within UK chiropractic.

      Research

      The terms “research” and “science” appear frequently in the chiropractic literature with a variety of meanings “unfamiliar to most scientists”
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      (Table 2). Many early chiropractors felt the need to obtain an “aura of scientific respectability” as marketing ploys for promoting their practice to the public.
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      This attitude seems to be still prevalent. A leading Canadian chiropractor, for instance, was quoted saying that research “is something that you have to do, no question. We have to have the research to be accepted properly.”
      • Kelner M.
      • Wellman B.
      • Welsh S.
      • Boon H.
      How far can complementary and alternative medicine go? The case of chiropractic and homeopathy.
      The concept that research is a means of improving future health care does not seem widespread within the chiropractic profession.
      Table 2Quotes from the Chiropractic Literature Related to Science
      DateAuthorQuote
      1897Palmer DDChiropractic is a science of healing without drugs
      1906Palmer DD, Palmer BJThe science of chiropractic
      1910Palmer DDThe science, art and philosophy of chiropractic
      1911Palmer BJThe philosophy, science and art of chiropractic nerve tracing
      1917CarvorThe first scientific statement of the science of chiropractic
      1946Ratledge TFThe ultra-scientific nature of the chiropractic concept
      1985DishmanScientific basis for the chiropractic subluxation complex
      1994Martin SCThe demonstration of a new scientific law that healed the sick was an important contribution to the revealing of God's beneficence
      The little research that did take place during the early years of chiropractic was of remarkably low quality. Research was initiated to prove rather than to test chiropractic.
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      The data that thus emerged were subject to “zealous overinterpretation.”
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      For instance, observational studies were wrongly characterized as controlled clinical trials.
      • Palmer B.J.
      Chiropractic controlled clinical trials.
      The current chiropractic research literature continues to be overtly biased. An evaluation of the 29 recent reviews of spinal manipulation for back pain concluded that those authored by chiropractors tended to generate positive results, whereas the others failed to demonstrate effectiveness.
      • Canter P.H.
      • Ernst E.
      Sources of bias in reviews of spinal manipulation for back pain.
      Today's “straight” chiropractors believe that research “never establishes truth”
      • Strauss J.B.
      Refined by fire: the evolution of straight chiropractic.
      and deny the relevance of science to chiropractic.

      Gold R. Presentation at the Los Angeles College of Chiropractic, November 18, 1994.

      “We cannot second guess whether the innate intelligence of the body can heal a disease.”
      • Strauss J.B.
      Refined by fire: the evolution of straight chiropractic.
      Belief in subluxation is an essential prerequisite for any chiropractor—so much so that questioning this belief is grounds for banishment from the profession; therefore, scientific investigation of chiropractic, which obviously requires questioning that belief, is (by definition) not possible for chiropractors.
      • Keating J.C.J.
      Purpose-straight chiropractic: not science, not health care.
      There is “a shortage of chiropractic clinicians who have the experience and training to conduct clinical research.”
      • Sawyer C.
      • Haas M.
      • Nelson C.
      • Elkington W.
      Clinical research within the chiropractic profession: status, needs and recommendations.
      A survey of Californian chiropractic students suggested that 52% of them are interested in research, 26% have research experience, 19% thought research training should be in their curriculum but “most students…were reluctant to take on extra courses in research.”
      • Zhang J.Q.
      Research attitudes among chiropractic college students.
      It is, therefore, not surprising that “many of the key clinical trials…were conducted in Europe and Canada.”
      • Redwood D.
      Chiropractic.

      Current Evidence

      Efficacy

      Kusserow noted that, “overtly aggressive marketing [is]…deliberately aimed at misleading patients and the public regarding the efficacy of chiropractic care.”
      • Kusserow R.P.
      Chiropractic services under Medicare. Office of Analysis and Inspections, Office of the Inspector General.
      In fact, unsubstantiated claims regarding the efficacy of chiropractic continue to be made, not merely by overenthusiastic individuals but also by official organizations. For instance, a patient brochure published by the UK General Chiropractic Council (the body that oversees chiropractic in Great Britain) stated that “chiropractors primarily treat: spine, neck and shoulder problems, joint, posture and muscle problems, sciatica, sports injuries, tension headaches and benefit may also be seen for some types of asthma, digestive disorders, migraine, infant colic, menstrual pains.”

      General Chiropractic Council. Protecting patients. What can I expect when I see a chiropractor? ISBN: 1-903559-09-X. 2003. http://www.gcc-uk.org/files/link_file/whatcanIExpect_Sep07_Web.pdf. Accessed January 21, 2008.

      This statement clearly implies that chiropractic is helpful for these indications. Yet the evidence from rigorous clinical trials fails to confirm this.
      Numerous controlled clinical studies of chiropractic are now available, but their results are far from uniform. Rather than selecting single studies according to their findings, it is, therefore, preferable to consider the totality of this evidence. Table 3 gives an overview of the most up-to-date systematic reviews by indication.
      • Assendelft W.J.J.
      • Morton S.C.
      • Yu Emily I.
      • Suttorp M.J.
      • Shekelle P.G.
      Spinal manipulative therapy for low-backpain.
      • Gross A.R.
      • Hoving J.L.
      • Haines T.A.
      • et al.
      Manipulation and mobilisation for mechanical neck disorders (Cochrane Review).
      • Fernandez-de-Las-Penas C.
      • Alonso-Blanco C.
      • Cuadrado M.L.
      • et al.
      Are manual therapies effective in reducing pain from tension-type headache?: a systematic review.
      • Ernst E.
      Chiropractic spinal manipulation for neck pain—a systematic review.
      • Proctor M.L.
      • Hing W.
      • Johnson T.C.
      • Murphy P.A.
      Spinal manipulation for primary and secondary dysmenorrhoea.
      • Husereau D.
      • Clifford T.
      • Aker P.
      • Leduc D.
      • Mensinkai S.
      Spinal manipulation for infantile colic. Technology report no 42.
      • Balon J.W.
      • Mior S.A.
      Chiropractic care in asthma and allergy.
      • Reid S.A.
      • Rivett D.A.
      Manuel therapy treatment of cervicogenic dizziness: a systematic review.
      These systematic reviews usually include trials of spinal manipulation regardless of who administered it. Thus, they are not exclusively an evaluation of chiropractic. Collectively, their results fail to demonstrate that spinal manipulation is effective. The only possible exception is back pain. For this condition, manipulation may be as effective (or ineffective) as standard therapy.
      • Assendelft W.J.J.
      • Morton S.C.
      • Yu Emily I.
      • Suttorp M.J.
      • Shekelle P.G.
      Spinal manipulative therapy for low-backpain.
      Table 3Systematic Reviews of (Chiropractic) Spinal Manipulation
      First Author (Year)InterventionsConditionnMeta-analysisOverall result
      Quote from authors' conclusions.
      Comment
      Assendelft et al. (2004)
      • Assendelft W.J.J.
      • Morton S.C.
      • Yu Emily I.
      • Suttorp M.J.
      • Shekelle P.G.
      Spinal manipulative therapy for low-backpain.
      Any type of SMLow back pain39YesNo evidence that SM is superior to other standard treatments for acute or chronic low back painAlso included RCTs of mobilization
      Gross et al. (2004)
      • Gross A.R.
      • Hoving J.L.
      • Haines T.A.
      • et al.
      Manipulation and mobilisation for mechanical neck disorders (Cochrane Review).
      Any type of SM and mobilizationNeck problems33Yes…evidence did not favor SM/mobilization done aloneCombined with exercise, SM was beneficial
      Fernandez-de-las-Penas et al. (2006)
      • Fernandez-de-Las-Penas C.
      • Alonso-Blanco C.
      • Cuadrado M.L.
      • et al.
      Are manual therapies effective in reducing pain from tension-type headache?: a systematic review.
      All types of manual therapies (3 trials of spinal manipulation)Tension type headache (TTH)6No“…no rigorous evidence that manual therapies have a positive effect on the evolution of TTH”2 RCTs were of high quality but generated contradictory results
      Ernst (2003)
      • Ernst E.
      Chiropractic spinal manipulation for neck pain—a systematic review.
      Chiropractic SMNeck pain4NoThe notion that chiropractic SM is more effective than conventional exercise…was not supported by rigorous trial dataIncluded only RCTs of chiropractic SM.
      Proctor et al. (2001)
      • Proctor M.L.
      • Hing W.
      • Johnson T.C.
      • Murphy P.A.
      Spinal manipulation for primary and secondary dysmenorrhoea.
      Any type of SMPrimary and secondary dysmenorrhea5NoThere is no evidence that SM is effective4 of the 5 RCTs were of high velocity, low amplitude thrusts
      Husereau et al. (2003)
      • Husereau D.
      • Clifford T.
      • Aker P.
      • Leduc D.
      • Mensinkai S.
      Spinal manipulation for infantile colic. Technology report no 42.
      Any type of SMInfantile colic4NoNo convincing evidenceMost trials were of low methodological quality
      Balon and Mior (2004)
      • Balon J.W.
      • Mior S.A.
      Chiropractic care in asthma and allergy.
      Chiropractic careAsthma/allergy6NoNo evidence to support the use of chiropractic SM4 of the 6 trials tested SM; 3 of these studies were negative
      Reid and Rivett (2005)
      • Reid S.A.
      • Rivett D.A.
      Manuel therapy treatment of cervicogenic dizziness: a systematic review.
      Manual therapy mainly manipulation and mobilizationCervicogenic dizziness9No…there is limited evidence at present to support the use of manual therapy in treating cervicogenic dizziness.Only one of the trials was randomized.
      This table includes all indications for which systematic reviews are available. If for any indication more than one systematic review exists, the most recent one was chosen.
      n=number of trials included, SM=spinal manipulation, RCT=randomized clinical trial.
      a Quote from authors' conclusions.
      Many national guidelines recommend chiropractic for acute or chronic low back pain.
      • Bigos S.
      • Bowyer O.
      • Braen G.
      • et al.
      Acute low back problems in adults. Clinical practice guideline No. 14. AHCPR Publication No. 95-0642.
      • Bogduk N.
      Australasian Faculty of Musculoskeletal Medicine for the National Musculoskeletal Medicine Initiative. Evidence-based clinical guidelines for the management of acute low back pain.
      Royal College of General Practitioners. Clinical guidelines for the management of acute low back pain.
      • Manniche C.
      • Ankjær-Jensen A.
      • Olsen A.
      • et al.
      Low-back pain: frequency, management and prevention from an HTA perspective.
      • van Tulder M.W.
      • Goossens M.
      • Waddell G.
      • Nachemson A.
      Conservative treatment of chronic low back pain.
      The reason may not be the convincingly demonstrated effectiveness of chiropractic care but the fact that no therapy so far has been shown to make a real difference for back pain sufferers. Recent studies suggest that a prospectively identifiable subgroup of patients with back pain may benefit from spinal manipulation, whereas others do not.
      • Childs J.D.
      • Fritz J.M.
      • Flynn T.W.
      • et al.
      A clinical prediction rule to identify patients with low back pain most likely to benefit from spinal manipulation: a validation study.
      • Fritz J.M.
      • Childs J.D.
      • Flynn T.W.
      Pragmatic application of a clinical prediction rule in primary care to identify patients with low back pain with a good prognosis following a brief spinal manipulation intervention.
      • Brennan G.P.
      • Fritz J.M.
      • Hunter S.J.
      • et al.
      Identifying subgroups of patients with acute/subacute “nonspecific” low back pain: results of a randomized clinical trial.
      • Fritz J.M.
      • Brennan G.P.
      • Leaman H.
      Does the evidence for spinal manipulation translate into better outcomes in routine clinical care for patients with occupational low back pain? A case–control study.
      If this turns out to be true, it could help to explain the so far unconvincing trial results. Other recent data suggest that, for back pain, educational programs may be preferable to treatments such as spinal manipulation, which tend to medicalize back pain sufferers.
      • Heymans M.W.
      • van Tulder M.W.
      • Esmail R.
      • Bombardier C.
      • Koes B.W.
      Back schools for nonspecific low back pain: a systematic review within the framework of the Cochrane Collaboration Back Review Group.
      Few of the primary studies have been adequately controlled for placebo effects, an objective which is difficult but not impossible to achieve. Thus, some of the benefit reported in the above-mentioned studies could be due to a placebo response. A survey of 34 Australian “leaders of the chiropractic profession” suggested that the majority of chiropractors agree that the placebo effect is a major contributor to the perceived benefit of chiropractic. Some even felt that “at least half” of the chiropractic success is due to placebo effects.
      • Jamison J.R.
      Chiropractic holism: accessing the placebo effect.
      According to the chiropractic literature, absolute contraindications of chiropractic include osteoporosis, local malignancies, bone fractures, bone infections, and bleeding disorders,
      • Dagenais S.
      • Haldeman S.
      Chiropractic.
      as well as active inflammatory arthropathy, ligamentous laxity, hypermobility, local metastases, dislocations, myelopathy, and cauda equina syndrome.
      • Gay R.E.
      Chiropractic.
      Relative contraindications include severe spondylosis, distant malignancies/metastases, local benign tumors, spinal trauma, chronic sponylarthropathy, history of spinal surgery, acute soft tissue or disc injuries, history of verbrobasilar insufficiency, and osteopenia.
      • Gay R.E.
      Chiropractic.

      Safety

      Direct Risks

      “Chiropractic is safe”
      • Killinger L.Z.
      Chiropractic and geriatrics: a review of the training, role, and scope of chiropractic in caring for aging patients.
      —in the chiropractic literature, statements like this can be found abundantly. Table 4
      • Cohn A.
      A review of the literature regarding stroke and chiropractic.
      • Fillippi M.R.
      Approaches to unsubstantiated criticism: an editorial rejoinder on the stoke (sic) issue.
      • Michaud T.C.
      Uneventful upper cervical manipulation in the presence of a damaged vertebral artery.
      • Haneline M.T.
      • Croft A.C.
      • Frishberg B.M.
      Association of internal carotid artery dissection and chiropractic manipulation.
      • Haneline M.T.
      • Croft A.C.
      Internal carotid artery dissection following chiropractic.
      • Mirallas-Martinez J.A.
      Cerebral vascular complications post-cervical spine manipulation.
      • Refisch A.
      • Bischoff P.
      Manipulation and lesions of the cervical arteries More than a temporal coincidence?.
      • Oliphant D.
      Safety of spinal manipulation in the treatment of lumbar disk herniations: a systematic review and risk assessment.
      • Haneline M.
      • Triano J.
      Cervical artery dissection. A comparison of highly dynamic mechanisms: manipulation versus motor vehicle collision.
      depicts some of the arguments currently used by chiropractors to deny that spinal manipulation can cause harm or to trivialize its risks.
      Table 4Quotes from the Recent Chiropractic Literature Regarding Safety
      DateAuthorQuoteRef. No.
      2001CohnThe occurrence of cerebral vascular accidents (CVAs) in the general population is 0.224% while the occurrence of CVAs in the chiropractic population is 0.000008%.
      • Cohn A.
      A review of the literature regarding stroke and chiropractic.
      2001Filippi…this latest ungrounded association [of chiropractic] with stroke etiology serves as a final straw in a long and tedious process of professional identity.
      • Fillippi M.R.
      Approaches to unsubstantiated criticism: an editorial rejoinder on the stoke (sic) issue.
      2002Michaud…vigorous manipulation of the upper cervical spine is possible without injuring an already damaged vertebral artery.
      • Michaud T.C.
      Uneventful upper cervical manipulation in the presence of a damaged vertebral artery.
      2003Haneline et al.The medical literature does not support a clear causal relationship between chiropractic manipulative therapy and internal carotid artery dissection.
      • Haneline M.T.
      • Croft A.C.
      • Frishberg B.M.
      Association of internal carotid artery dissection and chiropractic manipulation.
      2003Haneline and Croft…a causal relationship [between chiropractic manipulation and internal carotid artery dissection] is not supported by the literature.
      • Haneline M.T.
      • Croft A.C.
      Internal carotid artery dissection following chiropractic.
      2003Mirallas-Martinez…mortality due to surgical interventions of lumbar spine is 300 times greater than due to post-cervical manipulation stroke.
      • Mirallas-Martinez J.A.
      Cerebral vascular complications post-cervical spine manipulation.
      2004Refisch and Bischoff…the relationship between cervical manipulation and lesions of the cervical arteries…must be negated.
      • Refisch A.
      • Bischoff P.
      Manipulation and lesions of the cervical arteries More than a temporal coincidence?.
      2004OliphantAn estimate of the risk of spinal manipulation causing a clinical worsened disk herniation or cauda equina syndrome…is calculated…to be less than 1 in 3.7 million.
      • Oliphant D.
      Safety of spinal manipulation in the treatment of lumbar disk herniations: a systematic review and risk assessment.
      2005Haneline and TrianoThe direct evidence suggests that the healthy vertebral artery is not at risk from properly performed chiropractic manipulative procedures.
      • Haneline M.
      • Triano J.
      Cervical artery dissection. A comparison of highly dynamic mechanisms: manipulation versus motor vehicle collision.
      In 2001, a systematic review of five prospective studies concluded that mild-to-moderate, transient adverse effects are experienced by about half of all chiropractic patients.
      • Ernst E.
      Prospective investigations into the safety of spinal manipulation.
      Local or radiating pain, headache, and tiredness are the most frequent adverse effects. Since then, two further prospective studies (n=465 and 336, respectively) reported that such adverse effects occur in 61% and 30% of patients.
      • Cagnie B.
      • Vinck E.
      • Beernaert A.
      • Cambier D.
      How common are side effects of spinal manipulation and can these side effects be predicted?.
      • Hurwitz E.L.
      • Morgenstern H.
      • Vassilaki M.
      • Chiang L.M.
      Frequency and clinical predictors of adverse reactions to chiropractic care in the UCLA neck pain study.
      Therefore, there is undeniable evidence that chiropractic is associated with an exorbitantly high incidence of minor adverse effects.
      Spinal manipulation of the upper spine has frequently been associated with serious vascular accidents. A systematic review summarized the data up to November 2001,
      • Stevinson C.
      • Ernst E.
      Risks associated with spinal manipulation.
      and an update reviewed the latest evidence.
      • Ernst E.
      Adverse effects of spinal manipulation: a systematic review.
      In total, this disclosed around 700 serious complications and about 50 deaths. Five surveys have been published asking doctors to report instances where their patients have experienced serious adverse effects after spinal manipulation.
      • Lee K.P.
      • Carlini W.G.
      • McCormick G.F.
      • Albers G.W.
      Neurologic complications following chiropractic manipulation: a survey of Californian neurologists.
      • Lynch P.
      Incidence of neurological injury following neck manipulation.
      • Stevinson C.
      • Honan W.
      • Cooke B.
      • Ernst E.
      Neurological complications of cervical spine manipulation.
      • Dupeyron A.
      • Vautravers P.
      • Lecocq J.
      • Isner-Horobeti M.E.
      Complications following vertebral manipulation—a survey of a French region physicians.
      • Egizii G.
      • Dupeyron A.
      • Vautravers P.
      Spinal manipulation: survey of French medical physicians who graduated with the national diploma of osteopathy from Strasbourg university.
      The results invariably disclosed a multitude of complications after chiropractic manipulation. More importantly, they demonstrated that these instances had not previously been reported in the medical literature. In other words, underreporting had been 100%. Therefore, it seems highly doubtful whether reliable incidence figures can presently be calculated. A recent systematic review found 14 cases of adverse effects of spinal manipulation in children, 10 of which involved serious complications such as subarachnoidal hemorrhage or paraplegia.

      Johnston BC, Cramer K, Humphreys K, Vohra S. Adverse events associated with spinal manipulation in children: a systematic review. ConferenceAbstracts. CARE Program, Department of Pediatrics, Alberta, Canada. May/June 2006:52–53.

      Table 5 lists a selection of recently published case reports
      • Jeret J.S.
      More complications of spinal manipulation.
      • Siegel D.
      • Neiders T.
      Vertebral artery dissection and pontine infarct after chiropractic manipulation.
      • Parwar B.L.
      • Fawzi A.A.
      • Arnold A.C.
      • Schwartz S.D.
      Horner's syndrome and dissection of the internal carotid artery after chiropractic manipulation of the neck.
      • Schram D.J.
      • Vosik W.
      Diaphragmatic paralysis following cervical chiropractic manipulation: case report and review.
      • Jeret J.S.
      • Bluth M.
      Stroke following chiropractic manipulation. Report of 3 cases and review of the literature.
      • Sedat J.
      • Dib M.
      • Mahagne M.H.
      • Lonjon M.
      • Paquis P.
      Stroke after chiropractic manipulation as a result of extracranial postero-inferior cerebellar artery dissection.
      • Jay W.M.
      • Shah M.I.
      • Schneck M.J.
      Bilateral occipital-parietal hemorrhagic infarctions following chiropractic cervical manipulation.
      • Menendez Gonzalez M.
      • Garcia C.
      • Suarez E.
      • Fernandez Diaz D.
      • Blazquez Menes B.
      Wallenberg's syndrome caused by chiropractic manipulation.
      • Wojcik W.
      • Pawlak J.K.
      • Knaus R.
      Doctor! I can't stand the noise in my ear!.
      • Beck J.
      • Raabe A.
      • Seifert V.
      Intracranial hypotension after chiropractic manipulation of the cervical spine.
      • Nadgir R.N.
      • Loevner L.A.
      • Ahmed T.
      • et al.
      Simultaneous bilateral internal carotid and vertebral artery dissection following chiropractic manipulation: case report and review of the literature.
      • Oehler J.
      • Gandjour J.
      • Fiebach J.
      • Schwab B.
      • Beidseitige A.
      Vertebralis-Dissektion nach chiropraktischer Behandlung (Dissection of vertebral artery after chiropractic therapy).
      • Yokota J.
      • Amakusa Y.
      • Tomita Y.
      • Takahashi S.
      The medial medullary infarction (Dejerine syndrome) following chiropractic neck manipulation.
      • Izquierdo-Casas J.
      • Soler-Singla L.
      • Viva-Diaz E.
      • et al.
      Diseccion vertebral como causa del sindrome de enclaustramiento y opciones terapeuticas con fibrinolisis intraarterial durante la fase aguda (Locked-in syndrome due to a vertebral dissection and therapeutic options with intraarterial fibrinolysis in acute phase).
      • Saxler G.
      • Barden B.
      Extensive spinal epidural hermatoma—an uncommon entity following cervical chiropractic manipulation.
      • Tome F.
      • Barriga A.
      • Espejo L.
      Multiple discal herniation after chiropractic manipulation.
      associating chiropractic treatments with serious complications.
      Table 5Recent (2001–2006) Case Reports of Serious Adverse Events After Chiropractic Spinal Manipulation
      First Author (Year)Patient(s)Adverse EventOutcome
      Jeret (2001)
      • Jeret J.S.
      More complications of spinal manipulation.
      34-year-old man with neck pain after whiplash injuryDural tear, positional dizzinessFull recovery
      Siegel and Neiders (2001)
      • Siegel D.
      • Neiders T.
      Vertebral artery dissection and pontine infarct after chiropractic manipulation.
      33-year-old woman with headacheVertebral artery dissection followed by pontine infarctPermanent, severe neurological deficit
      Parwar et al. (2001)
      • Parwar B.L.
      • Fawzi A.A.
      • Arnold A.C.
      • Schwartz S.D.
      Horner's syndrome and dissection of the internal carotid artery after chiropractic manipulation of the neck.
      44-year-old man with shoulder painDissection of right internal carotic artery, Horner's syndromeNot reported
      Schram and Vosik (2001)
      • Schram D.J.
      • Vosik W.
      Diaphragmatic paralysis following cervical chiropractic manipulation: case report and review.
      47-year-old man with neck and shoulder painPhrenic nerve injury, diaphragmatic paralysis, severe dyspneaResidual dyspnea
      Jeret and Bluth (2002)
      • Jeret J.S.
      • Bluth M.
      Stroke following chiropractic manipulation. Report of 3 cases and review of the literature.
      31-year-old womanDissection of left vertebral arteryComplete recovery
      Sedat et al. (2002)
      • Sedat J.
      • Dib M.
      • Mahagne M.H.
      • Lonjon M.
      • Paquis P.
      Stroke after chiropractic manipulation as a result of extracranial postero-inferior cerebellar artery dissection.
      42-year-old woman with neck painDissection of extracranial port of the right PICAResidual headache and stiffness on discharge from hospital
      Jay et al. (2003)
      • Jay W.M.
      • Shah M.I.
      • Schneck M.J.
      Bilateral occipital-parietal hemorrhagic infarctions following chiropractic cervical manipulation.
      26-year-old woman with headache and sinusitisBilateral dissection of vertebral arteries followed by bilateral occipital-parietal hemorrhagic infarction and visual impairmentNot mentioned
      Menendez-Gonzalez et al. (2003)
      • Menendez Gonzalez M.
      • Garcia C.
      • Suarez E.
      • Fernandez Diaz D.
      • Blazquez Menes B.
      Wallenberg's syndrome caused by chiropractic manipulation.
      33-year-old patientDissection of vertebral artery followed by Wallenberg's syndromeNot mentioned
      Wojcik et al. (2003)
      • Wojcik W.
      • Pawlak J.K.
      • Knaus R.
      Doctor! I can't stand the noise in my ear!.
      46-year-old female patient with neck painDural tearComplete recovery
      Beck et al. (2003)
      • Beck J.
      • Raabe A.
      • Seifert V.
      Intracranial hypotension after chiropractic manipulation of the cervical spine.
      40-year-old female patientWallenberg syndromeNo information provided
      Nadgir et al. (2003)
      • Nadgir R.N.
      • Loevner L.A.
      • Ahmed T.
      • et al.
      Simultaneous bilateral internal carotid and vertebral artery dissection following chiropractic manipulation: case report and review of the literature.
      34-year-old manBilateral internal carotic and vertebral artery dissectionResidual left-side hemianesthesia and dysesthesia
      Oehler et al. (2003)
      • Oehler J.
      • Gandjour J.
      • Fiebach J.
      • Schwab B.
      • Beidseitige A.
      Vertebralis-Dissektion nach chiropraktischer Behandlung (Dissection of vertebral artery after chiropractic therapy).
      31-year-old woman with headacheBilateral dissections of vertebral arteriesNot mentioned
      Yokota et al. (2003)
      • Yokota J.
      • Amakusa Y.
      • Tomita Y.
      • Takahashi S.
      The medial medullary infarction (Dejerine syndrome) following chiropractic neck manipulation.
      38-year-old manDissection of left vertebral artery followed by Dejerine syndromeNot mentioned
      Izquiedo-Casas et al. (2004)
      • Izquierdo-Casas J.
      • Soler-Singla L.
      • Viva-Diaz E.
      • et al.
      Diseccion vertebral como causa del sindrome de enclaustramiento y opciones terapeuticas con fibrinolisis intraarterial durante la fase aguda (Locked-in syndrome due to a vertebral dissection and therapeutic options with intraarterial fibrinolysis in acute phase).
      37-year-old womanDissection of vertebral artery followed by tertraparesisFibrinolysis resulted in complete recanalization of the artery
      Saxler and Barden (2004)
      • Saxler G.
      • Barden B.
      Extensive spinal epidural hermatoma—an uncommon entity following cervical chiropractic manipulation.
      27-year-old womanEpidural hematoma extending from cervical to sacral spineComplete recovery
      Tome et al. (2004)
      • Tome F.
      • Barriga A.
      • Espejo L.
      Multiple discal herniation after chiropractic manipulation.
      40-year-old patientMultiple cervical disc herniationNot mentioned
      In all cases, causality was deemed to be certain or likely, and in all instances was the therapist a chiropractor.

      Indirect Risks

      Further safety concerns relate to indirect risks of chiropractic. The above-named review

      Johnston BC, Cramer K, Humphreys K, Vohra S. Adverse events associated with spinal manipulation in children: a systematic review. ConferenceAbstracts. CARE Program, Department of Pediatrics, Alberta, Canada. May/June 2006:52–53.

      noted 20 cases of delayed or missed diagnoses through consulting a chiropractor. A similar but better researched indirect risk is the attitude of many chiropractors toward immunization. The early chiropractic literature is littered with statements against immunization. Palmer's original concepts were seen by chiropractors as a complete explanation of all medical conditions, their prevention, and treatments. Infectious diseases, therefore, put the gospel of D.D. Palmer in doubt (see above); consequently, their existence was denied, and so was the benefit of immunization. The faculty and administration of Williard Carver's “Chiropractic Research University” were even jailed for refusing “to submit to the compulsory vaccination law of the District of Columbia.”
      • Keating J.C.J.
      • Green B.N.
      • Johnson C.D.
      “Research” and “science” in the first half of the chiropractic century.
      The current chiropractic literature continues to promote “hostile opposition to health prevention based upon immunization procedures”
      • Anderson R.
      Chiropractors for and against vaccines.
      and repeatedly stresses that immunization is hazardous and ineffective.
      • Kent C.
      • Gentempo P.
      Immunisation; facts; myths and speculation.
      • Koren T.
      The vaccine dilemma: another viewpoint on the issue.
      In doing so, facts are distorted: “Smallpox vaccination was stopped in the U.S. and U.K. because it was realized that the vaccinated suffered the worst effects of the disease;”
      • Durant A.
      Vaccination, antibiotics and paediatrics: where do we stand.
      or the risks of immunization are exaggerated: “The dangers of vaccination to the young child are profound… in some cases, the vaccine acts non-specifically to increase a child's pre-existing chronic disease tendency.”
      • Peet P.M.
      • Peet J.
      Chiropractic pediatric and prenatal reference manual.
      Other sources state that immunization is useless and harmful: “Immunisation programmes continue on the premise of prevention” but “it cannot be said that the…programme has been proven successful…and the complication rates for the vaccines continues to claim the lives of children via disability and/or death.”
      • Swenson R.L.
      Pediatric disorders.
      Others again report that, “vaccination appears to increase the risk of allergies and related respiratory symptoms.”
      • Hurwitz E.L.
      • Morgenstern H.
      Effects of diphtheria-tetanus-pertussis or tetanus vaccination on allergies and allergy-related respiratory symptoms among children and adolescents in the United States.
      There is no shortage of strong statements in the chiropractic literature warning patients of “having toxic filth squirted into the bodies” of their children.
      • Anderson R.
      Chiropractors for and against vaccines.
      Even though some chiropractors would probably deny this, the anti-immunization lobby of chiropractors is still very strong; the only place where chiropractors are prohibited from lobbying against immunization is in Ontario, Canada.

      College of Chiropractors of Ontario. Accessed May 7, 2007. Available at http://www.cco.on.ca/standard_of_practice_s-015.htm.

      A U.S. survey was aimed at identifying chiropractors' attitudes toward immunization.
      • Colley F.
      • Haas M.
      Attitudes on immunization. A survey of American Chiropractors.
      A random sample (1%) of all U.S. chiropractors was provided with a choice of policy statements. One-third of the sample agreed with the statements that there is no scientific proof that immunization prevents disease, that it causes more disease than it prevents, and that contracting an infectious disease is safer than immunization. Another survey was performed on 150 licensed chiropractors from Boston. About 30% of them reported to recommend active immunization and 7% recommended their clients against immunization.
      • Lee A.C.C.
      • Li D.H.
      • Kemper K.J.
      Chiropractic care for children.
      A Canadian interview study recently confirmed that some chiropractors provide to their patients “information of a negative, anti-vaccination nature.”
      • Page S.A.
      • Russell M.L.
      • Verhoef M.J.
      • Injeyan H.S.
      Immunization and the chiropractor-patient interaction: a Western Canadian study.

      Cost

      A World Health Organization-sponsored, systematic review of cost analyses in complementary medicine included seven investigations related to spinal manipulation or chiropractic care.
      • Thompson Coon J.
      • Ernst E.
      A systematic review of the economic evaluation of complementary and alternative medicine.
      It concluded that “there is no evidence to suggest that chiropractic is a more cost-effective treatment option than physiotherapy or hospital outpatient treatment for low back pain.”
      • Thompson Coon J.
      • Ernst E.
      A systematic review of the economic evaluation of complementary and alternative medicine.
      Since then, several new studies have become available. A UK trial compared disability scores after spinal manipulation (carried out by chiropractors, osteopaths, or physiotherapists), exercise classes, or manipulation followed by exercise in addition to care for chronic back pain by general practitioners.
      UK BEAM Trial Team
      United Kingdom back pain exercise and manipulation (UK BEAM) randomised trial: cost effectiveness of physical treatments for back pain in primary care.
      Exercise was superior to primary care at three months but not after one year. Manipulation alone or followed by exercise generated better outcomes than primary care at 3 and 12 months. Effect sizes were, however, small to moderate. The mean incremental treatment cost relative to general practitioner care was £195 for manipulation, £140 for exercise, and £125 for the combined treatment. The authors estimated the cost per Quality Adjusted Life Years as £3,800 for combined treatment and £4,800 for manipulation.
      A retrospective analysis of the U.S. worker's compensation payment data from a single insurer analyzed the figures from individuals suffering from work-related low back injuries between 1999 and 2002.
      • Wasiak R.
      • McNeely E.
      Utilization and costs of chiropractic care for work-related low back injuries: do payment policies make a difference?.
      The results showed that restrictive payment policies were associated with lower cost of chiropractic care and lower number of services per visit, but did not affect the visits or services per person.
      Legorreta et al.
      • Legorreta A.P.
      • Metz R.D.
      • Nelson C.F.
      • et al.
      Comparative analysis of individuals with and without chiropractic coverage: patient characteristics, utilization, and costs.
      retrospectively analyzed claims data of more than one million members of a U.S. health care plan. Access to chiropractic care was associated with lower cost for neuromuscular complaints and back pain. This effect could be due to these patients being younger and healthier than nonchiropractic patients.
      • Ness J.
      • Nisly N.
      Cracking the problem of back pain: is chiropractic the answer?.
      Others have noted that users of chiropractic are also high users of conventional health services,
      • Sibbritt D.
      • Adams J.
      • Young A.F.
      A profile of middle-aged women who consult a chiropractor or osteopath: findings from a survey of 11,143 Australian women.
      which renders cost savings an unlikely prospect.

      Conclusion

      This overview will be rejected by proponents of chiropractic for being biased or one-sided, but its purpose was to offer a critical evaluation. At present, such an assessment has not been provided by chiropractors, yet progress in any field is difficult without critical evaluation.
      Chiropractors' belief in the “innate,” subluxation, or spinal manipulation is not rational. Current chiropractic practice raises numerous concerns. The effectiveness, safety, and cost of spinal manipulation are uncertain. More and better quality studies are, therefore, required. Until convincing data are available, we might question the value of this popular approach to health care.

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