Impact of Dyspnea, Pain, and Fatigue on Daily Life Activities in Ambulatory Patients with Advanced Lung Cancer
Article Outline
Abstract
This study aimed to compare the impact of dyspnea, pain, and fatigue on daily life activities in ambulatory patients with advanced lung cancer. One hundred seventy-one outpatients with advanced lung cancer completed a questionnaire about symptom severity and whether symptoms interfered with daily life activities (normal work, walking, sleep, mood, relation with other people, enjoyment of life, and general activities). The results indicated that 1) dyspnea and fatigue interfered with at least one daily life activity in more than half the patients, and pain in about 40%, 2) dyspnea and fatigue interfered predominantly with physical activities, such as walking and work, whereas pain interfered with all activities almost equally, and 3) symptoms rated as low severity (1 to 3 on a 0–10-point numerical scale) were severe enough to interfere with at least one daily life activity. To recognize the impact of symptoms may contribute to provide better management.
Keywords: Lung cancer, dyspnea, pain, fatigue, impact, symptom
Introduction
Lung cancer is the most common cause of cancer mortality in the world and is one of the most prevalent cancers.1 The overall morbidity of this disease is dramatically increasing worldwide, and its 5-year survival remains disappointedly low, at approximately 14%.2 To alleviate symptoms is, therefore, the priority, and symptom-oriented medicine is sometimes preferred rather than disease-oriented in this population.3, 4
Patients with lung cancer experience various distressing symptoms during the course of illness.5 Although the frequency of these symptoms varies widely across studies due to patient selection, lack of clear symptom definition, and variation in measurement techniques, there is nonetheless some consistency. The most common symptoms in newly diagnosed lung cancer patients at any stage and those undergoing therapy for advanced disease are fatigue, pain, anorexia, insomnia, cough, and dyspnea.6, 7, 8, 9, 10, 11 Those in the palliative care setting experience pain, dyspnea, and anorexia most commonly.12 Thus, pain, dyspnea, and fatigue seem to be the most common symptoms. These symptoms also are the most frequent in other cancer populations, especially in the terminal stages.10, 13
It has been reported that lung cancer patients experience more symptom distress than patients with other cancer.7 These distressing symptoms strongly influence emotional wellbeing, not only of patients but also families.14, 15 In such circumstances, it is easy to imagine that these symptoms interfere with daily life activities. No study, however, has focused on the impact of symptoms on daily life. To provide better management for advanced lung cancer patients, especially whose life expectancies are limited, it is important to know the impact of symptoms on daily life activities.
The purposes of this study were to identify: 1) how often three frequent symptoms (dyspnea, pain, and fatigue) interfere with daily life activities in ambulatory patients with advanced lung cancer, 2) whether there are any differences in the features of these symptoms regarding impact on daily life activities, and 3) whether a 0–10-point numerical scale is feasible for screening those symptoms interfering with at least one daily life activity, and if feasible, at which level the cut-off point is.
Methods
Patients
The subjects were consecutive ambulatory lung cancer patients in the Thoracic Oncology Division of the National Cancer Center Hospital East in Chiba and of the National Cancer Center Hospital in Tokyo, Japan. Eligible patients were required: a) to be pathologically diagnosed as having lung cancer and to have been informed of their diagnosis, b) to be in an advanced stage clinically (i.e., in clinical stage IIIA [unresectable], IIIB, or IV) or recurrent stage, c) to be well enough to complete the questionnaire, and d) not to be suffering from severe mental or cognitive impairment. They were a part of a sample of a project, the results of which have been published elsewhere.16
This study was approved by the Institutional Review Board and the Ethics Committee of the National Cancer Center, Japan. Written consent was obtained after each patient had been fully informed of the purpose of the study.
Procedures
The participants were asked to complete a questionnaire at home and mail it back. If there were any blanks, telephone inquiry was used to obtain the missing answers, as agreed by the participants. Each participant was given a 500-yen prepaid telephone card for participating in the study.
The severity of dyspnea, pain, and fatigue was evaluated with numerical scales, ranging from 0 (no dyspnea/pain/fatigue) to 10 (dyspnea/pain/fatigue as bad as you can imagine). Validity and reliability of the numerical scale were confirmed to be satisfactory, as reported elsewhere by authors.17 The advantages of the numerical rating scales have been also discussed elsewhere.18
The impact of these three symptoms on daily life activities was evaluated with a questionnaire asking whether dyspnea (or pain/fatigue) had interfered with the following seven items of daily life activities in the previous 24 hours: normal work, walking, sleep, mood, relation with other people, enjoyment of life, and general activities of life. They were originally from the Brief Pain Inventory, which is a scale to assess interference of pain with common functions in daily life.19 The developers of the latter scale have grouped the seven activities into two dimensions using factor analysis: activity dimension (work, walking, general, and sleep) and affective dimension (mood, relationship, enjoyment).20 In this study, interference was evaluated by “presence” or “absence,” simplifying the 0–10 numerical scales used in the Brief Pain Inventory. The validity and reliability of this type of interference question was confirmed to be satisfactory, as reported elsewhere.17
Patients' demographic information, such as sex and age, and medical information, such as pathology, clinical stage, cancer treatments, number of days since the diagnosis of cancer, current medication, and concurrent morbidity, were obtained from their medical records. Performance status (PS), defined by Eastern Cooperative Oncology Group, was judged clinically by experienced physicians. Social information, such as marital status, employment status and education level, was obtained in an interview by one of the authors (K.T.).
The cut-off points for screening symptoms interfering with at least one daily life activity were determined by using Receiver Operating Characteristic (ROC) curve. The optimal cut-off point was decided as follows. First, the point was chosen where the sum of false-positive and false-negative was minimum. Second, when sensitivity was clearly lower than specificity, the balance between them was considered to provide enough sensitivity rather than specificity, because overdiagnosis of these symptoms is more beneficial than missing it with a higher cut-off point.21
Results
Demographic and Clinical Characteristics
A total of 184 consecutive outpatients were candidates for the study between May and July 1998. Seven patients were ineligible due to physical illness and/or cognitive impairment. Two (1%) refused because of lack of time or feeling too ill, and four (2%) were excluded because they failed to complete the questionnaires. While age and sex showed no significant difference between non-participants (n = 13) and participants (n = 171), PS of the non-participants was significantly worse than that of the participants (mean PS ± SD, 1.9 ± 0.9, 0.9 ± 0.6, respectively, z = −2.2, P < 0.05, Wilcoxon's rank test).
Demographic and clinical characteristics of the 171 included patients are shown in Table 1. The PS of 95% cases were 0 to 1, and one-fifth were able to work. The median number of days after diagnosis of cancer was about one year. Although the majority of patients were married, 6% lived alone.
Table 1. Demographic and Clinical Characteristics of Subjects (n = 171)
| Characteristics | n(%) |
|---|---|
| Age (yrs); mean ± SD (median) range | 63.0 ± 9.3 (64) 27–80 |
| Sex | Male 122 (71) |
| Hospital | |
| NCCHEa | 134 (78) |
| NCCHb | 37 (22) |
| Pathology | |
| NSCLCc | 142 (83) |
| SCLCd | 29 (17) |
| Clinical stage | |
| IIIA(unresectable) | 30 (18) |
| IIIB | 55 (32) |
| IV | 37 (22) |
| recurrent | 49 (29) |
| PS (ECOG)e | |
| 0 | 36 (21) |
| 1 | 126 (74) |
| 2 | 7 (4) |
| 3 | 1 (1) |
| 4 | 1 (1) |
| Prior cancer treatment (including overlapping) | |
| Chemotherapy | 135 (79) |
| Irradiation | 88 (51) |
| Surgery | 38 (22) |
| Days after diagnosis of cancer; mean ± SD (median) range | 610 ± 657 (348) 15–3138 |
| Current medication ( including overlapping ) | |
| Opioids | 27 (16) |
| Anxiolytics | 25 (15) |
| Corticosteroids | 17 (10) |
| Concurrent morbidity (including overlapping) | |
| Hypertension | 22 (13) |
| Diabetes mellitus | 12 (7) |
| COPDf | 3 (2) |
| Marital status | |
| Married | 145 (85) |
| Household size | |
| Lives alone | 10 (6) |
| Working status | |
| Works outside | 33 (19) |
| Education | |
| ⩽9 yrs | 75 (43) |
| Symptom severity; mean ± SD (median) rangeg | |
| Dyspnea | 2.2 ± 2.1 (2) 0–9 |
| Pain | 1.7 ± 2.1 (1) 0–10 |
| Fatigue | 2.5 ± 2.1 (2) 0–9 |
a National Cancer Center Hospital East, Chiba. |
b National Cancer Center Hospital, Tokyo. |
c Non-small cell lung cancer. |
d Small cell lung cancer. |
e Performance status according to Eastern Cooperative Oncology Group. |
f Chronic obstructive pulmonary disease. |
g Evaluated with a 0–10-point numerical scale (0: none, 10: very severe). |
Symptom severity varied. The patients with severe symptoms were the minority. The numbers of the patients who rated dyspnea, pain, and fatigue as 6 or worse were 14 (8%), 13 (8%), and 17 (10%), respectively. The median pain score was 1, and that of dyspnea and fatigue was 2 on the 0–10 point scales.
The Prevalence of Interference
Dyspnea interfered with at least one daily life activity in 94 patients (55%), pain in 70 (41%), and fatigue in 89 (52%)(Fig. 1). Dyspnea interfered with walking and work in over 30% of the patients, but with other activities much less frequently, between 10% and 20%. Pain interfered with mood the most frequently, in a quarter of the cases, and with other activities at a rate of 15–25%. The frequency order of disturbed activities by fatigue was the same as dyspnea.
Fig. 1.
Correlations between symptom severity, rated on a 0–10-point numerical scale, and the accumulated percentage of patients whose activities were disturbed (n = 171).
Dyspnea rated as low as 1 already interfered with at least one daily life activity of 13% cases, and pain rated as low as 1 interfered with at least one in 11%. The number whose activities were disturbed increased with symptom severity. Fatigue rated as 1 interfered with at least one activity in 5% of the cases, which was the lowest frequency among the three symptoms, but the number of the patients whose activities were disturbed increased with increasing fatigue severity, up to 52% of the cases when fatigue was severe. Walking and work were disturbed by fatigue rated as low as 4 in about 20% of the cases, whereas mood and enjoyment were disturbed in approximately 20% by fatigue rated as severe as 7.
The median (mean ± SD) number of the activities disturbed by dyspnea, pain, and fatigue were 1 (1.4 ± 1.9), 0 (1.4 ± 2.3), and 1 (1.7 ± 2.1), respectively. Although about one-half of the patients were not disturbed in any activities at all (45% by dyspnea, 59% by pain, 48% by fatigue), about one-third were disturbed in not a single but multiple activities (35% by dyspnea, 30% by pain, and 39% by fatigue).
Cut-Off Points for Screening Symptoms Interfering with Daily Life Activities
Tentative cut-off points, and their sensitivities and specificities according to the ROC curve, are shown in Table 2. According to the criteria described above, the optimal cut-off point for dyspnea was decided to be 0/1, which gave 96.8% sensitivity and 55.1% specificity, that for pain was 1/2 with 72.9% and 84.3%, and that for fatigue was 2/3 with 73.0% and 88.0% (sensitivity and specificity in this order, respectively). Sensitivity and specificity of pain and fatigue were both over 70%, which were satisfactory.
Table 2. Sensitivity and Specificity for the Screening of Symptoms Interfering with Any Activities, According to the ROCa Curve
| Dyspnea | Pain | Fatigue | ||||
|---|---|---|---|---|---|---|
| Cut-off Pointb | Sensitivity | Specificity | Sensitivity | Specificity | Sensitivity | Specificity |
| 0/1 | 0.968 | 0.551c | 0.943 | 0.578 | 0.989 | 0.561 |
| 1/2 | 0.585 | 0.731 | 0.729 | 0.843c | 0.899 | 0.675 |
| 2/3 | 0.362 | 0.910 | 0.600 | 0.941 | 0.730 | 0.880c |
| 3/4 | 0.287 | 0.974 | 0.371 | 1.000 | 0.472 | 0.964 |
a Receiver Operating Characteristic. |
b Tentative cut-off point on a 0–10-point numeric scale. |
c Underline shows the optimal cut-off point. |
Discussion
This is the first study that focused on comparing the impact of dyspnea, pain, and fatigue, which are the most frequent symptoms in lung cancer patients, on daily life activities in ambulatory patients with advanced lung cancer. The present findings revealed 1) dyspnea and fatigue interfered with at least one daily life activity in over half of patients, and pain interfered with at least one in about 40%; 2) dyspnea and fatigue interfered with physical activities predominantly, while pain interfered with all activities almost equally; and 3) the symptoms rated as low as 1 to 3 on a 0–10-point numerical scale were severe enough to interfere with at least one daily life activity.
There were some differences and some similarities regarding symptom impact on daily life activities. The most remarkable and suggestive differences was that dyspnea tended to interfere predominantly with physical activities, such as walking and work, rather than psychological condition, such as mood and enjoyment, whereas pain tended to interfere with psychological condition and physical activities to the similar degree. It is easy to understand that dyspnea interfered with physical activities predominantly, because physical activities induce imbalance between oxygen demand and supply, which evokes a degree of respiratory failure. Although it has been recently emphasized that dyspnea (a subjective phenomenon) should be distinguished from respiratory failure (as indicated, for example by hypoxia),16, 22 one of the causes of dyspnea may be respiratory failure.23 It was also not beyond expectation that pain interfered with mood the most frequently, because poorly controlled pain has been reported to be one of the risk factors for depression,24 which is the most common psychological syndrome in cancer patients.25 Being aware of such differences in symptom features may help clinicians provide appropriate management. For example, it is important to avoid unnecessary dyspnea on exertion by the temporary prophylactic use of oxygen or some lifestyle modifications. On the other hand, for pain management, it is important to pay attention to the impact of pain on psychological wellbeing, and not to overlook or underestimate the importance of depression.
There was notable similarity in the frequency of activities impaired by dyspnea and by fatigue. Walking, work, general activity, mood, enjoyment, relationships, and sleep were affected in this order. This implies that physical activities were more frequently disturbed than psychological ones by dyspnea and fatigue. From these findings, it might be hypothesized that when dyspnea and fatigue are mild, they interfere with physical activities first, and when symptoms are worsening, they gradually involve psychological activities. Walking and work were disturbed by fatigue rated as low as 4 in about 20% of the cases, whereas mood and enjoyment were disturbed in 20% only by fatigue rated as severe as 7. This finding also supports the hypothesis that psychological distress may be the sequela, rather than a precursor, of uncontrolled physical symptoms.
The present findings may give an important hint to better symptom control. If disturbance in mood, enjoyment, or relationships is observed, physical symptoms should be reevaluated and palliated. The prevalence of depression and adjustment disorders has been reported to be 32% in patients with all stages of cancer25 and 11% with terminal stage.26 The key to alleviation of depression for some of these patients may lie first in effective physical symptom management.
One limitation of this study is the lack of variance in symptoms. The patients were not terminally ill and were ambulatory. Those who were physically or cognitively not well were excluded. Most of the patients were, therefore, in good physical condition (95% of the cases were in PS 0 to 1) with mild symptoms (over 90% of them rated symptoms as 5 or less on a 0–10-point scale).
A second limitation is the difficulty of assessment. The Interference Questionnaire was originally developed and validated for pain assessment. Validity of assessment for other symptoms has not been confirmed properly. It might not be possible for many patients to assess functional consequences of these symptoms, and there might be other factors which are difficult to acknowledge as a cause of reduced function.
Temporal sequences also cannot be determined from the present data, because it is a cross-sectional study. To evaluate symptom impact on daily life activities, further study using a longitudinal design and a validated assessment method with heterogeneous population, including those with severe symptoms, is needed.
As a screening tool for picking up symptoms interfering with at least one daily life activity, a 0–10 numerical scale was generally feasible. The present findings showed satisfactory sensitivity and specificity in pain and fatigue (73–88%). However, the cut-off point for dyspnea (0/1), which gave specificity 55.1%, also means that a 44.9% false positive rate is expected. This unsatisfactory result may reflect that dyspnea has a wide range of temporal and exertion-related change.
The findings about cut-off points were suggested, in spite of these concerns. Symptoms rated as low as 0 to 3 on a 0–10-point scale were severe enough to interfere with at least one daily life activity. It is to be emphasized that the cut-off point of dyspnea is 0/1, which means that even a small degree of dyspnea evoked an adverse impact on activities. Second, the cut-off points varied with symptoms; that is, the same severity does not mean the same degree of impact on daily life activities. Dyspnea rated as 1 (beyond the cut-off point) needs more active intervention than fatigue rated as 1 (below the cut-off point). It is important, therefore, to assess the impact on daily life separately from the severity.
Despite the limitations discussed above, the present study suggests that there may be differences in the features of dyspnea, pain, and fatigue regarding impact of daily life activities. Recognizing these features may contribute to better management and improve the quality of life of the patients whose lifetime at home is unfortunately limited.
Acknowledgements
The authors are grateful to the anonymous patients who gave their time so willingly. We also acknowledge Charles S. Cleeland, PhD, Pain Research Group, M.D. Anderson Cancer Center, for giving us permission to use the concept of “interference,” which he developed in the Brief Pain Inventory; the physicians of the Thoracic Oncology Division of the National Cancer Center Hospital East (Drs. R. Kakinuma, Y. Ohe, F. Hojo, T. Matsumoto, H. Ohmatsu) and those of the National Cancer Center Hospital (Drs. N. Saijo, T. Kodama, K. Kubota, T. Tamura, T. Shinkai, H. Kunitoh, I. Sekine) for enrollment of their patients in this study; and Y. Kojima, K. Harada, Y. Sugihara, M. Sakai, and R. Katayama for their research assistance. This work was supported in part by Grants-in-Aid for Research (9-31) and the Second Term Comprehensive 10-year Strategy for Cancer Control from the Ministry of Health and Welfare, Japan.
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© 2002 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.
