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Dyspnea Self-Management in Patients With Chronic Obstructive Pulmonary Disease: Moderating Effects of Depressed Mood
Dyspnea Self-Management in Patients With Chronic Obstructive Pulmonary Disease: Moderating Effects of Depressed Mood HUONG Q. NGUYEN, PH.D., R.N. VIRGINIA CARRIERI-KOHLMAN, R.N., D.N.SC.
The effects of three versions of a dyspnea self-management program on depressed mood and the moderating effects of baseline depression risk on improvements in dyspnea severity, exercise performance, and physical and social functioning were examined over a 2-month period in 100 patients with moderate to severe chronic obstructive pulmonary disease (COPD). All three versions of the dyspnea self-management programs, which differed in the amount of supervised exercise (no sessions or four or 24 sessions), equally and significantly improved depressed mood. Subjects at high risk for depression at study entry who received 24 sessions had greater reduction in dyspnea than those who received four sessions or no sessions. Patients with COPD at high risk for depression are likely to achieve greater relief of dyspnea with self-management programs that include more intensive supervised exercise. (Psychosomatics 2005; 46:402–410)
D
epression is a commonly reported emotional problem associated with chronic obstructive pulmonary disease (COPD); the prevalence of depression in COPD patients has been estimated to range from 25% to 74%.1,2 The wide range in estimated prevalence is primarily due to differences in the demographic characteristics of the study samples, measurement properties of instruments, and cutoff values used to define depression.3 Nonetheless, the finding that COPD patients are at high risk for depression is consistent. The disease likely serves as an antecedent that increases the level of mediating variables such as depression and dyspnea, which, in turn, diminish functional status
Received Oct. 23, 2003; revision received June 21, 2004; accepted July 22, 2004. From the Department of Biobehavioral Nursing and Health Systems, University of Washington School of Nursing; and the Department of Physiological Nursing, University of California, San Francisco, School of Nursing, San Francisco. Address correspondence and reprint requests to Dr. Nguyen, Department of Biobehavioral Nursing and Health Systems, University of Washington School of Nursing, Box 357266, Seattle, WA 98155; [email protected] (e-mail). Copyright 䉷 2005 The Academy of Psychosomatic Medicine.
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and quality of life.4,5 It is important to note that most of the studies of depression that are cited in this article are based on psychological questionnaires rather than clinical diagnoses, unless otherwise stated. In one case-control study, van Manen et al.1 found the risk for depression to be 2.5 times greater for patients with severe COPD (forced expiratory volume in 1 second [FEV1]⬍50% predicted) than for comparison subjects with similar demographic characteristics. Greater severity of depression in patients with COPD has been associated with diminished health-related quality of life,6–9 diminished functional status,10 impaired coping,11 greater COPD symptoms,1,9,12–14 and failure of treatment for COPD exacerbations.15 Mortality risk was three times greater for patients who had depressive symptoms during hospitalization for COPD exacerbations, compared to those who did not have depressive symptoms.16 Compared to patients with other chronic illnesses, such as heart failure, arthritis, angina, and diabetes, patients with COPD have been found to have worse psychological functioning.17 Depressed mood and/or depression have been meaPsychosomatics 46:5, September-October 2005
Nguyen and Carrieri-Kohlman sured as an outcome of multipronged treatments such as pulmonary rehabilitation or self-management interventions, both of which typically include some form of exercise. Some18–22 but not all23,24 of these studies have demonstrated a positive effect on depression. Exercise is often implicated as the active ingredient in modifying depressed mood in these investigations; however, the granular effects (i.e., dose frequency, duration, and intensity) of exercise in improving depressed mood have not been examined sufficiently in healthy people and not at all in patients with COPD.25 In addition, few studies have assessed the moderating effects of depressed mood on changes in health outcomes from such treatments in patients with COPD. We previously reported the main results from an experimental study evaluating three dyspnea self-management (DM) programs, two of which included additive doses of supervised exercise in addition to a standard program of individualized education and home-based walking for patients with COPD.26 We found that the effect on dyspnea severity, exercise performance, and health-related quality of life was largely dependent on the “dose” of supervised exercise (no, four, or 24 sessions) in that subjects who received the extended training outperformed the other two groups. In this article, we report on the effects of the three DM programs on depressed mood and present subgroup analyses of the moderating effects of baseline depression risk on improvement in the primary study outcome variables of dyspnea severity, exercise performance, and social and physical functioning. METHOD Design The data used for this secondary analysis are from a randomized clinical trial of the three DM programs. The study methods have been reported in-depth elsewhere26 and are therefore described only briefly in this article. After baseline testing, subjects were randomly assigned to one of three treatment groups (DM, DM plus four supervised exercise sessions, or DM plus 24 supervised exercise sessions; see “Interventions” later in this section). Outcomes were measured at baseline and at 2 months. Of the 115 subjects who were randomly assigned to study groups, 12 dropped out for various reasons, including illness, disinterest, and transportation problems, leaving 103 subjects who completed the 2-month evaluation. The study protocol was approved by the institutional review board, and each subject gave informed written consent. Psychosomatics 46:5, September-October 2005
Subjects Subjects were recruited by advertisements and referrals from numerous sources, including physicians’ offices and Better Breathers Clubs of the American Lung Association. Entry criteria were age ⬎40 years, confirmation of a diagnosis of moderate to severe COPD (i.e., FEV1 ⬍60% of the predicted level or a ratio of FEV1 to forced vital capacity ⬍60%) with clinical stability for at least 1 month, no participation in formal exercise training or pulmonary rehabilitation in the previous year, and absence of other active symptomatic diseases that would interfere with exercise (e.g., cancer, coronary artery disease, heart failure, psychiatric illness). Interventions The basic DM program included three components: individual education and demonstration of strategies for self-management of dyspnea, an individualized home-based walking prescription, and exercise selfmonitoring that included use of a pedometer and exercise log (see Appendix 1 for more details). Subjects in the group who received DM plus four supervised exercise sessions received the basic DM program plus a total of four nurse-supervised treadmill exercise sessions once every other week for 2 months. The goal of the exercise sessions was steady-state symptom-limited exercise consisting of continuous walking for as long as 30 minutes at the endurance treadmill test workload. Subjects in the group who received DM plus 24 supervised exercise sessions received the basic DM program plus 24 nurse-supervised treadmill exercise sessions three times per week over 2 months. The exercise sessions were identical to those received by the subjects who received four supervised exercise sessions. Pulmonary Function Testing Subjects performed spirometry 15–30 minutes after receiving two puffs of albuterol administered by means of a spacer (Aerochamber; Monaghan, Plattsburg, N.Y.). Spirometry was performed with a 10-liter water-seal spirometer (Collins Medical, Braintree, Mass.) according to American Thoracic Society criteria.27 Baseline lung volumes (helium dilution method), maximum voluntary ventilation, single-breath diffusion capacity for carbon monoxide, and residual volume over total lung capacity were measured by using a body plethysmograph (Collins Plus Body Plethysmography System; Collins Medical, Braintree, Mass.). http://psy.psychiatryonline.org
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Depressed Mood in COPD Measurements Depressed mood The Center for Epidemiological Studies Depression (CES-D) Scale is a 20-item self-administered instrument developed for use in epidemiological studies of depressive symptoms in the general population.28 The cutoff score of 16 was identified as the 80th percentile of scores in the general population and is used to identify individuals at high risk for depression. This cutoff score was shown to have a sensitivity of 73% and specificity of 84% for detecting depression in hospitalized, medically ill, elderly patients.29 In this study, subjects were classified as having a higher level of depressed mood and/or as being at high risk for depression if they scored above 15 on the CES-D Scale. Cronbach alpha for the CES-D Scale in this study was 0.85. Dyspnea with activities of daily living The Chronic Respiratory Questionnaire (CRQ) is an interviewer-administered disease-specific quality-of-life questionnaire for patients with COPD that includes 20 questions assessing four health status domains.30 The dyspnea subscale (CRQ-D) measures the severity of dyspnea in the past 2 weeks during five activities of daily living (ADLs) chosen by the patient as being important in his or her daily life. Cronbach alpha for the CRQ-D in this study was 0.73. Exercise performance Subjects performed a symptomlimited endurance treadmill test according to a previously reported protocol.26 Each subject performed the endurance treadmill test at a workload one level below the maximum workload completed during their baseline incremental test. Standard physiological measurements were made during the endurance treadmill test (Sensormedics 2900, Yorba Linda, Calif.), and all equipment was calibrated immediately before each test. Self-reported functioning The physical and social functioning scales of the Medical Outcomes Study Short Form Health Survey (SF-36) were used.31 The SF-36 is a valid and reliable measure of self-reported functioning for patients with COPD.31,32 Cronbach alphas in this study were 0.86 and 0.70 for the physical and social functioning scales, respectively. Statistical Analysis Results are reported as means and standard deviations. Univariate analyses of covariance were performed on the 404
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data for each dependent variable by treatment group (i.e., DM, DM plus four exercise sessions, and DM plus 24 exercise sessions) and depression risk group (subjects with CES-D Scale scores ⬎15 and subjects with CES-D Scale scores ⱕ15) while controlling for age, disease severity, gender, antidepressant use, and baseline scores for the respective variable. This design allowed for testing of the main effects of treatment group and depression risk and the interaction of the two factors. If the interaction was significant, post hoc pair-wise contrasts were performed. A p value of ⬍0.05 was considered significant. All analyses were conducted by using SPSS 12.0 for Windows (SPSS, Inc., Chicago). RESULTS A total of 115 subjects were randomly assigned to treatment groups. Four subjects from each treatment group dropped out before the first evaluation at 2 months. Three additional subjects had unusable data on at least one of the outcome variables, leaving 100 subjects with complete data. Demographic and pulmonary function data are presented in Table 1, and baseline scores by treatment group and depression risk findings are presented in Table 2. The overall study group had significant improvement in CES-D Scale scores from baseline (mean⳱13.3, SD⳱8.9) to 2 months (mean⳱12.0, SD⳱9.5) (F⳱4.5, df⳱1, 97, p⳱0.04); no differences between the treatment groups were found. Subgroup analyses of the 36 subjects with a CES-D Scale score ⬎15 at baseline also showed a significant time effect from baseline (mean⳱23.1, SD⳱6.1) to 2 months (mean⳱20.0, SD⳱11.1) (F⳱7.1, df⳱1, 33, p⳱0.002), with no group-by-time differences (F⳱0.06, df⳱2, 33, p⳱0.94). The number of subjects who were at high risk for depression was equally distributed across the three treatment groups (v2⳱2.3, df⳱2, p⳱0.32). Only four of the 36 subjects at high risk for depression (11%) reported taking an antidepressant at study entry. Figure 1, Figure 2, Figure 3, and Figure 4 show the improvements in dyspnea with ADLs, exercise performance, social functioning, and physical functioning measures, respectively, from baseline to 2 months for the three treatment groups according to depression risk (baseline CES-D Scale scores). There was a significant interaction of treatment group and depression risk in improvements in dyspnea with ADLs (F⳱3.7, df⳱2, 89, p⳱0.03). Subjects who were at higher risk for depression at baseline who received DM plus 24 exercise sessions had substantially Psychosomatics 46:5, September-October 2005
Nguyen and Carrieri-Kohlman greater reductions in dyspnea (mean change⳱6.8, SD⳱1.4), compared to those who received either DM (mean change⳱1.3, SD⳱0.9; t⳱5.0, df⳱25, p⳱0.03) or DM plus four exercise sessions (mean change⳱1.1, SD⳱1.6; t⳱4.9, df⳱19, p⳱0.01). For subjects who were at low risk for depression, DM plus four exercise sessions was comparable to DM plus 24 exercise sessions in im-
TABLE 1.
Characteristics of Patients With Chronic Obstructive Pulmonary Disease (Nⴔ100) in a Study of the Effects of Three Dyspnea Self-Management Programs on Depressed Mood
Characteristic Gender Female Male Age (years) Forced expiratory volume in 1 second (FEV1) (liters) FEV1 (% of predicted level) FEV1/forced vital capacity (%) Maximum voluntary ventilation (% of predicted level) Residual volume/total lung capacity (%) Diffusion capacity of carbon monoxide (% of predicted level)
TABLE 2.
proving dyspnea (t⳱1.9, df⳱43, p⳱0.13) but was better than DM (t⳱3.1, df⳱41, p⳱0.02). There were no significant main effects of depression risk on the improvements in any of the three remaining outcomes of endurance exercise, social functioning, and physical functioning. However, subjects with higher depression risk were more likely to report a greater increase in social functioning than those
Patients Who Received Dyspnea Self-Management (DM)
Patients Who Received DM Plus Four Supervised Exercise Sessions
Patients Who Received DM Plus 24 Supervised Exercise Sessions
N
%
N
%
N
%
15 19 Mean 65.8
44 56 SD 9.0
18 14 Mean 67.1
56 44 SD 7.7
22 12 Mean 66.2
65 35 SD 6.4
1.1 43.1 39.7
0.38 18.7 14.2
1.2 48.5 43.4
0.31 12.8 8.7
1.0 43.7 43.6
0.30 9.9 11.2
39.2 53.7
16.1 9.8
46.4 53.0
15.5 10.0
41.0 55.4
11.8 10.6
63.3
21.9
68.3
22.0
64.4
17.6
Baseline Dyspnea, Exercise Endurance, and Social and Physical Functioning Scores in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa Dyspnea With Activities of Daily Livingb
Treatment Group and Depression Risk Dyspnea self-management (DM) Patients with CES-D Scale score ⱕ15 (N⳱19) Patients with CES-D Scale Score ⬎15 (N⳱15) DM plus four supervised exercise sessions Patients with CES-D Scale score ⱕ15 (N⳱23) Patients with CES-D Scale score ⬎15 (N⳱9) DM plus 24 supervised exercise sessions Patients with CES-D Scale score ⱕ15 (N⳱22) Patients with CES-D Scale score ⬎15 (N⳱12)
Exercise Endurance Time (minutes)c
Social Functioning Scored
Physical Functioning Scoree
Mean
SD
Mean
SD
Mean
SD
Mean
SD
16.8 14.9
5.9 5.1
7.4 6.7
4.0 7.2
69.1 51.7
23.3 24.9
36.2 30.7
15.9 21.3
17.9 16.0
3.9 4.8
6.2 8.0
3.2 6.7
84.2 47.2
15.6 16.3
43.0 32.2
17.4 13.8
16.7 14.3
5.2 3.9
6.6 6.7
4.3 4.2
76.1 44.8
23.1 14.6
35.0 24.6
18.8 11.8
CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. Measured with the dyspnea subscale of the Chronic Respiratory Questionnaire.30 Higher scores indicate better health status. c Measured with a symptom-limited endurance treadmill test. Higher times indicate better health status. d Measured with the social functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31 Higher scores indicate better health status. e Measured with physical functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31 Higher scores indicate better health status. a
b
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Depressed Mood in COPD who were not at risk, regardless of the treatment group, although the difference did not reach significance (F⳱2.0, df⳱2, 89, p⳱0.17). DISCUSSION In subjects with moderate to severe COPD: 1) all three versions of a 2-month program of dyspnea self-management equally and significantly improved depressed mood both in a subset of subjects at high risk for depression and in the overall study group, 2) those at high risk for depression at study entry had greater reductions in dyspnea from intensive supervised exercise training (DM plus 24 supervised exercise sessions) than from the other two programs (DM and DM plus four supervised exercise sessions), and 3) there were no significant main effects of depression risk on improvements in exercise performance, social functioning, and physical functioning. The CES-D Scale, which has fewer somatic items compared to other available instruments, was used in this study to assess the presence of depressed mood, not to FIGURE 1.
Change in Dyspnea With Activities of Daily Living (ADL) in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
make a clinical diagnosis of depression. Subjects with a score of 15 or higher at baseline were considered at high risk for clinical depression.33 According to this criterion, 36% of the subjects in our study were considered at risk for depression at baseline. This prevalence of depression symptoms appears to be congruent with other research findings, but it is likely an underestimate, because depression may deter COPD patients from participating in research studies.1,24 Of greater importance, only four subjects at risk for clinical depression were medically treated at baseline. This finding parallels that of an earlier study in which a mere 6% of oxygen-dependent COPD patients who were classified as depressed according to the Geriatric Depression Scale were taking an antidepressant.7 These observations are concerning yet not surprising, given that one recent national study in the United States reported that patients with a diagnosis of depression received only approximately one-half of the recommended level of care.34 On average, the patients recruited for this study, which was based at a major academic medical center, did not exhibit high levels of depressive mood at baseline yet were still able to reduce their CES-D Scale scores with all three FIGURE 2.
Change in Exercise Endurance Time in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa Dyspnea self-management (DM)
DM plus 24 exercise sessions
DM plus four exercise sessions
10
DM plus 24 exercise sessions 14
8
p=0.03 p=0.01
6 p=0.02
4
2
12 10 8 6 4 2
0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the dyspnea subscale of the Chronic Respiratory Questionnaire.30
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Mean Change in Exercise Endurance Time (minutes)b
Mean Change in Dyspnea With ADL Scoreb
Dyspnea self-management (DM) DM plus four exercise sessions
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0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with a symptom-limited endurance treadmill test.
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Nguyen and Carrieri-Kohlman DM programs. The DM programs in our study were not designed as a treatment for depression per se; however, certain components such as improved knowledge about strategies to manage dyspnea, exercise, support from and contact with the nurse, which enhanced feelings of control over their symptoms,35 may have had a positive effect on their mood. Although the specific individual contributions from each of these components to improvement in depressed mood cannot be ascertained in this study, the literature suggests that exercise performed on a regular basis has a mild antidepressant effect.36 The optimal treatment for depression in patients with COPD has not been established. Although one study showed positive effects of pharmacotherapy for clinically depressed COPD patients,37 few other studies have corroborated these findings.38 The limited success in treating depression is not unique to patients with COPD; it continues to be a vexing challenge even in coronary heart disease, where substantial attention and research have been devoted to the testing of interventions to reduce the effect of depression on morbidity and mortality.39,40 Similar to our study, one recent study found signifi-
cantly greater reduction in depressed mood, as measured by the CES-D Scale, in patients with COPD who received pulmonary rehabilitation, compared with those who received usual care.21 However, these effects have not been consistent. Several other studies that tested exercise training alone,41 a similar pulmonary rehabilitation program,42 and a dyspnea education and skills training intervention43 have not shown improvements in depressed mood as measured by the CES-D Scale. The lack of improvement in the study by Etnier and Berry41 may have been due to a floor effect, but this explanation did not hold true for the other two studies. It is interesting to note that in other studies, the Beck Depression Inventory (BDI)44 and Hospital Depression Scale20 have been used to measure the effects on depression of short-term pulmonary rehabilitation and the Geriatric Depression Scale45 has been used to measure the effects on depression of brief cognitive behavior therapy for COPD patients. Investigators in these studies have reported notable changes in depression. One small study from Brazil recently showed the additive effects of psychotherapy above pulmonary rehabilitation alone in im-
FIGURE 3.
FIGURE 4.
Change in Social Functioning in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
Dyspnea self-management (DM) DM plus four exercise sessions
Mean Change in Social Functioning Scoreb
DM plus 24 exercise sessions
20
15
10
5
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the social functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31
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Mean Change in Physical Functioning Scoreb
Dyspnea self-management (DM) DM plus four exercise sessions 25
0
Change in Physical Functioning in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
DM plus 24 exercise sessions 12 10 8 6 4 2 0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the physical functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31
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Depressed Mood in COPD proving depression.46 In that study, patients with COPD who received 12 psychotherapy sessions in addition to a standard pulmonary rehabilitation program showed significantly greater improvement in depression (as measured by the BDI), compared to subjects who received rehabilitation alone. Although the 36 subjects in the current study who were at high risk for depression at baseline had significant reductions in their CES-D Scale scores after 2 months, they remained at high risk for depression. The use of concurrent psychotherapy with self-management interventions such as the DM program for patients with COPD and depression holds tremendous promise and will need to be tested. Subjects at lower risk for depression (those with CES-D Scale scores ⱕ15) in the groups that received DM and DM plus four exercise sessions tended to have improvement in dyspnea with ADLs that was, respectively, within the margins for and twice that of the criterion for a minimal clinically important difference (MCID) (for the CRQ-D, the MCID criterion is 2.5 points).47 In contrast, subjects who were at high risk for depression in these two treatment groups had minimal improvements in their dyspnea. These findings, coupled with the observed change in dyspnea that exceeded three times the MCID in subjects who had CES-D Scale scores ⬎15 and who received intensive supervised exercise training, suggest that programs with minimal supervised exercise may be inadequate for improving dyspnea in patients who have higher levels of depressed mood. For subjects who are at low risk for depression, DM plus four supervised exercise sessions may be adequate if the goal is to achieve clinically meaningful improvements in dyspnea. We are not aware of any other published studies that have documented the moderating effects of depressed mood on improvements in dyspnea with different doses of supervised exercise in patients with COPD. Depression can negatively affect adherence to treatments48 such as exercise and, therefore, may reduce the degree of improvements in health outcomes, as has been observed in patients with cardiac disease49–51 and in functionally disabled older patients.52 Adherence to the supervised exercise sessions was high in the group that received DM plus four exercise sessions (93%) and in the group that received DM plus 24 exercise sessions (100%).26 However, an analysis of both supervised and independent walking sessions showed that the groups that received DM and DM plus four exercise sessions logged fewer average weekly walking sessions
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than the group that received DM plus 24 exercise sessions during the 2 months.53 The intensive supervision likely served as a strong motivating force for consistent exercise and provided opportunities for subjects at high risk for depression to practice their dyspnea management strategies in a safe setting. Depression has also been shown to be a strong moderator of other health behaviors, such as smoking. Depressed smokers have been found to be 40% less likely to successfully quit smoking, compared with nondepressed smokers.54 Earlier cross-sectional studies showed that depressed mood was associated with social functioning but not physical functioning in patients with COPD.6,8 Subjects with higher CES-D Scale scores at baseline tended to have greater improvement in social functioning, compared to subjects who had lower CES-D Scale scores, regardless of their treatment group. This pattern suggests that if the goal is to improve social functioning in patients with COPD who have higher levels of depressed mood, all three versions of the DM program can be recommended. We did not observe any moderating effects of depressed mood on changes in exercise performance or physical functioning. It is more likely that nonpsychological factors have a greater influence than depression on exercise and physical functioning.45 CONCLUSIONS All three versions of a dyspnea self-management program significantly improved depressed mood in patients with moderate to severe COPD. Patients who were at high risk for depression at study entry benefited greatly in terms of greater reductions in dyspnea if they received more intensive supervised exercise training along with the dyspnea self-management program. Our findings will need to be replicated in a larger study that employs a factorial design and includes sufficient numbers of patients with depressed mood and/or a diagnosis of depression.55 Nonetheless, we recommend that self-management programs for patients with COPD screen for depression and tailor exercise regimens accordingly, e.g., providing more supervision for patients with depressed mood/depression, in order to maximize symptomatic improvements. The study was funded by National Institute of Nursing Research grant R01-NR02131-08 to Dr. Carrieri-Kohlman.
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APPENDIX 1.
Components of a Dyspnea Self-Management Program for Patients With Chronic Obstructive Pulmonary Disease
Component
Description
Individualized education, four sessions (3 hours total)
Topics included 1) identification of the patient’s triggers for dyspnea and previous self-care strategies for managing these triggers; 2) proper use of medications; 3) specific strategies for managing dyspnea, including breathing retraining, distraction, relaxation, and adjustment of oxygen with exercise; 4) benefits of homebased walking and integration of home-based walking into the patient’s lifestyle, with discussion of specific ways to overcome barriers. Patients were instructed to walk at least four times a week for a minimum of 20 minutes per session at their maximum pace so that they felt at the end of the walk that they could not have gone further. Patients were given a pedometer and daily logs. They recorded the time and distance walked and the level of dyspnea reached at the end of the walk using a 0–10 modified Borg scale.
Home-based walking exercise prescription Exercise self-monitoring
References
1. van Manen JG, Bindels PJ, Marcel Dekker FW, CJ IJ, van der Zee JS, Schade E: Risk of depression in patients with chronic obstructive pulmonary disease and its determinants. Thorax 2002; 57:412–416 2. Agle DP, Baum GL: Psychological aspects of chronic obstructive pulmonary disease. Med Clin North Am 1977; 61:749–758 3. van Ede L, Yzermans CJ, Brouwer HJ: Prevalence of depression in patients with chronic obstructive pulmonary disease: a systematic review. Thorax 1999; 54:688–692 4. McSweeney AJ, Grant I, Heaton RK, Adams KM, Timms RM: Life quality in patients with chronic obstructive pulmonary disease. Arch Intern Med 1982; 142:473–478 5. Williams SJ: Chronic respiratory illness and disability: a critical review of the psychosocial literature. Soc Sci Med 1989; 28:791– 803 6 . Kim HF, Kunik ME, Molinari VA, Hillman SL, Lalani S, Orengo CA, Petersen NJ, Nahas Z, Goodnight-White S: Functional impairment in COPD patients: the impact of anxiety and depression. Psychosomatics 2000; 41:465–471 7. Lacasse Y, Rousseau L, Maltais F: Prevalence of depressive symptoms and depression in patients with severe oxygen-dependent chronic obstructive pulmonary disease. J Cardpulm Rehabil 2001; 20:80–86 8. Felker B, Katon W, Hedrick SC, Rasmussen J, McKnight K, McDonnell MB, Fihn SD: The association between depressive symptoms and health status in patients with chronic pulmonary disease. Gen Hosp Psychiatry 2001; 23:56–61 9. Anderson KL: The effect of chronic obstructive pulmonary disease on quality of life. Res Nurs Health 1995; 18:547–556 10. Weaver TE, Narsavage GL: Physiological and psychological variables related to functional status in chronic obstructive pulmonary disease. Nurs Res 1992; 41:286–291 11. McCathie HC, Spence SH, Tate RL: Adjustment to chronic obstructive pulmonary disease: the importance of psychological factors. Eur Respir J 2002; 19:47–53 12. Dudley DL, Glaser EM, Jorgenson BN, Logan DL: Psychosocial concomitants to rehabilitation in chronic obstructive pulmonary disease, part I: psychosocial and psychological considerations. Chest 1980; 77:413–420 13. Small SP, Graydon JE: Perceived uncertainty, physical symptoms, and negative mood in hospitalized patients with chronic obstructive pulmonary disease. Heart Lung 1992; 21:568–574 14 . Graydon JE, Ross E: Influence of symptoms, lung function, mood, and social support on level of functioning of patients with COPD. Res Nurs Health 1995; 18:525–533
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15. Dahlen I, Janson C: Anxiety and depression are related to the outcome of emergency treatment in patients with obstructive pulmonary disease. Chest 2002; 122:1633–1637 16. Almagro P, Calbo E, Ochoa de Echaguen A, Barreiro B, Quintana S, Heredia JL, Garau J: Mortality after hospitalization for COPD. Chest 2002; 121:1441–1448 17. Stewart AL, Greenfield S, Hays RD, Wells K, Rogers WH, Berry SD, McGlynn EA, Ware JE Jr: Functional status and well-being of patients with chronic conditions: results from the Medical Outcomes Study. JAMA 1989; 262:907–913 18. Emery CF, Leatherman NE, Burker EJ, MacIntyre NR: Psychological outcomes of a pulmonary rehabilitation program. Chest 1991; 100:613–617 19. Emery CF, Schein RL, Hauck ER, MacIntyre NR: Psychological and cognitive outcomes of a randomized trial of exercise among patients with chronic obstructive pulmonary disease. Health Psychol 1998; 17:232–240 20. Withers NJ, Rudkin ST, White RJ: Anxiety and depression in severe chronic obstructive pulmonary disease: the effects of pulmonary rehabilitation. J Cardiopulm Rehabil 1999; 19:362–365 21. Bessell TL, McDonald S, Silagy CA, Anderson JN, Hiller JE, Sansom LN: Do Internet interventions for consumers cause more harm than good? a systematic review. Health Expect 2002; 5: 28–37 22. Griffiths TL, Burr ML, Campbell IA, Lewis-Jenkins V, Mullins J, Shiels K, Turner-Lawlor PJ, Payne N, Newcombe RG, Ionescu AA, Thomas J, Tunbridge J: Results at 1 year of outpatient multidisciplinary pulmonary rehabilitation: a randomised controlled trial. Lancet 2000; 355:362–368 23. Gayle RC, Spitler DL, Karper WB, Jaeger RM, Rice SN: Psychological changes in exercising COPD patients. Int J Rehabil Res 1988; 11:335–342 24. Toshima M, Blumberg E, Ries AL: Does rehabilitation reduce depression in patients with chronic obstructive pulmonary disease. J Cardpulm Rehabil 1992; 12:261–269 25. Dunn AL, Trivedi MH, O’Neal HA: Physical activity dose-response effects on outcomes of depression and anxiety. Med Sci Sports Exerc 2001; 33(suppl 6):S587–597; discussion 609–610 26. Stulbarg MS, Carrieri-Kohlman V, Demir-Deviren S, Nguyen HQ, Adams L, Tsang AH, Duda J, Gold WM, Paul S: Effect of exercise training on dyspnea, exercise performance and health related quality of life: how much training is enough? J Cardpulm Rehabil 2002; 22:109–121 27. Standardization of spirometry–1987 update. Statement of the American Thoracic Society. Am Rev Respir Dis 1987; 136:1285–1298
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Depressed Mood in COPD 28. Radloff L: The CES-D Scale: a self-report depression scale for research in the general population. J Applied Psychol Measurement 1977; 1:385–390 29. Koenig HG, O’Connor CM, Guarisco SA, Zabel KM: Depressive disorder in older medical inpatients on general medicine and cardiology services at a university teaching hospital. Am J Geriatr Psychiatry 1993; 1:197–210 30. Guyatt GH, Berman LB, Townsend M, Pugsley SO, Chambers LW: A measure of quality of life for clinical trials in chronic lung disease. Thorax 1987; 42:773–778 31. Ware JE Jr, Sherbourne CD: The MOS 36-item short-form health survey (SF-36): I. conceptual framework and item selection. Med Care 1992; 30:473–483 32. Mahler DA, Mackowiak JI: Evaluation of the short-form 36-item questionnaire to measure health-related quality of life in patients with COPD. Chest 1995; 107:1585–1589 33. Radloff LS, Teri L: Use of the Center for Epidemiological Studies– Depression Scale with older adults. Clin Gerontol 1986; 5:119– 136 34. McGlynn EA, Asch SM, Adams J, Keesey J, Hicks J, DeCristofaro A, Kerr EA: The quality of health care delivered to adults in the United States. N Engl J Med 2003; 348:2635–2645 35. Tsang AH, Carrieri-Kohlman V, Janson S, Gold WM, Stulbarg MS: Effectiveness of three interventions to improve self-efficacy for managing dyspnea in patients with COPD. Am J Respir Crit Care Med 2001; 163:A968 36. Singh NA, Clements KM, Singh MA: The efficacy of exercise as a long-term antidepressant in elderly subjects: a randomized, controlled trial. J Gerontol A Biol Sci Med Sci 2001; 56:M497– M504 37. Borson S, McDonald GJ, Gayle T, Deffebach M, Lakshminarayan S, VanTuinen C: Improvement in mood, physical symptoms, and function with nortriptyline for depression in patients with chronic obstructive pulmonary disease. Psychosomatics 1992; 33:190–201 38. Yohannes AM, Connolly MJ, Baldwin RC: A feasibility study of antidepressant drug therapy in depressed elderly patients with chronic obstructive pulmonary disease. Int J Geriatr Psychiatry 2001; 16:451–454 39. Berkman LF, Blumenthal J, Burg M, Carney RM, Catellier D, Cowan MJ, Czajkowski SM, DeBusk R, Hosking J, Jaffe A, Kaufmann PG, Mitchell P, Norman J, Powell LH, Raczynski JM, Schneiderman N, Enhancing Recovery in Coronary Heart Disease Patients Investigators (ENRICHD): Effects of treating depression and low perceived social support on clinical events after myocardial infarction: the enhancing recovery in coronary heart disease patients (ENRICHD) randomized trial. JAMA 2003; 289:3106–3116 40. Frasure-Smith N, Lesperance F, Prince RH, Verrier P, Garber RA, Juneau M, Wolfson C, Bourassa MG: Randomised trial of homebased psychosocial nursing intervention for patients recovering from myocardial infarction. Lancet 1997; 350:473–479 41. Etnier JL, Berry M: Fluid intelligence in an older COPD sample
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after short- or long-term exercise. Med Sci Sports Exerc 2001; 33:1620–1628 42. Ries AL, Kaplan RM, Limberg TM, Prewitt LM: Effects of pulmonary rehabilitation on physiologic and psychosocial outcomes in patients with chronic obstructive pulmonary disease. Ann Intern Med 1995; 122:823–832 43. Sassi-Dambron DE, Eakin EG, Ries AL, Kaplan RM: Treatment of dyspnea in COPD: a controlled clinical trial of dyspnea management strategies. Chest 1995; 107:724–729 44. Kozora E, Tran ZV, Make B: Neurobehavioral improvement after brief rehabilitation in patients with chronic obstructive pulmonary disease. J Cardiopulm Rehabil 2002; 22:426–430 45. Kunik ME, Braun U, Stanley MA, Wristers K, Molinari V, Stoebner D, Orengo CA: One session cognitive behavioural therapy for elderly patients with chronic obstructive pulmonary disease. Psychol Med 2001; 31:717–723 46. de Godoy DV, de Godoy RF: A randomized controlled trial of the effect of psychotherapy on anxiety and depression in chronic obstructive pulmonary disease. Arch Phys Med Rehabil 2003; 84:1154–1157 47. Jaeschke R, Singer J, Guyatt GH: Measurement of health status: ascertaining the minimal clinically important difference. Controlled Clin Trial 1989; 10:407–410 48. DiMatteo MR, Lepper HS, Croghan TW: Depression is a risk factor for noncompliance with medical treatment: meta-analysis of the effects of anxiety and depression on patient adherence. Arch Intern Med 2000; 160:2101–2107 49. Ades PA, Waldmann ML, McCann WJ, Weaver SO: Predictors of cardiac rehabilitation participation in older coronary patients. Arch Intern Med 1992; 152:1033–1035 50. Blumenthal JA, Williams RS, Wallace AG, Williams RB Jr, Needles TL: Physiological and psychological variables predict compliance to prescribed exercise therapy in patients recovering from myocardial infarction. Psychosom Med 1982; 44:519–527 51. Glazer KM, Emery CF, Frid DJ, Banyasz RE: Psychological predictors of adherence and outcomes among patients in cardiac rehabilitation. J Cardiopulm Rehabil 2002; 22:40–46 52. Jette AM, Rooks D, Lachman M, Lin TH, Levenson C, Heislein D, Giorgetti MM, Harris BA: Home-based resistance training: predictors of participation and adherence. Gerontologist 1998; 38:412–421 53. Cuenco D: Predictors of Adherence to Home Walking in Patients With COPD (doctoral dissertation). San Francisco, University of California, San Francisco, School of Nursing, Department of Physiological Nursing, 2004 54. Anda RF, Williamson DF, Escobedo LG, Mast EE, Giovino GA, Remington PL: Depression and the dynamics of smoking: a national perspective. JAMA 1990; 264:1541–1545 55. Dunn AL, Trivedi MH, Kampert JB, Clark CG, Chambliss HO: The dose study: a clinical trial to examine efficacy and dose response of exercise as treatment for depression. Control Clin Trials 2002; 23:584–603
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The effects of three versions of a dyspnea self-management program on depressed mood and the moderating effects of baseline depression risk on improvements in dyspnea severity, exercise performance, and physical and social functioning were examined over a 2-month period in 100 patients with moderate to severe chronic obstructive pulmonary disease (COPD). All three versions of the dyspnea self-management programs, which differed in the amount of supervised exercise (no sessions or four or 24 sessions), equally and significantly improved depressed mood. Subjects at high risk for depression at study entry who received 24 sessions had greater reduction in dyspnea than those who received four sessions or no sessions. Patients with COPD at high risk for depression are likely to achieve greater relief of dyspnea with self-management programs that include more intensive supervised exercise. (Psychosomatics 2005; 46:402–410)
D
epression is a commonly reported emotional problem associated with chronic obstructive pulmonary disease (COPD); the prevalence of depression in COPD patients has been estimated to range from 25% to 74%.1,2 The wide range in estimated prevalence is primarily due to differences in the demographic characteristics of the study samples, measurement properties of instruments, and cutoff values used to define depression.3 Nonetheless, the finding that COPD patients are at high risk for depression is consistent. The disease likely serves as an antecedent that increases the level of mediating variables such as depression and dyspnea, which, in turn, diminish functional status
Received Oct. 23, 2003; revision received June 21, 2004; accepted July 22, 2004. From the Department of Biobehavioral Nursing and Health Systems, University of Washington School of Nursing; and the Department of Physiological Nursing, University of California, San Francisco, School of Nursing, San Francisco. Address correspondence and reprint requests to Dr. Nguyen, Department of Biobehavioral Nursing and Health Systems, University of Washington School of Nursing, Box 357266, Seattle, WA 98155; [email protected] (e-mail). Copyright 䉷 2005 The Academy of Psychosomatic Medicine.
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and quality of life.4,5 It is important to note that most of the studies of depression that are cited in this article are based on psychological questionnaires rather than clinical diagnoses, unless otherwise stated. In one case-control study, van Manen et al.1 found the risk for depression to be 2.5 times greater for patients with severe COPD (forced expiratory volume in 1 second [FEV1]⬍50% predicted) than for comparison subjects with similar demographic characteristics. Greater severity of depression in patients with COPD has been associated with diminished health-related quality of life,6–9 diminished functional status,10 impaired coping,11 greater COPD symptoms,1,9,12–14 and failure of treatment for COPD exacerbations.15 Mortality risk was three times greater for patients who had depressive symptoms during hospitalization for COPD exacerbations, compared to those who did not have depressive symptoms.16 Compared to patients with other chronic illnesses, such as heart failure, arthritis, angina, and diabetes, patients with COPD have been found to have worse psychological functioning.17 Depressed mood and/or depression have been meaPsychosomatics 46:5, September-October 2005
Nguyen and Carrieri-Kohlman sured as an outcome of multipronged treatments such as pulmonary rehabilitation or self-management interventions, both of which typically include some form of exercise. Some18–22 but not all23,24 of these studies have demonstrated a positive effect on depression. Exercise is often implicated as the active ingredient in modifying depressed mood in these investigations; however, the granular effects (i.e., dose frequency, duration, and intensity) of exercise in improving depressed mood have not been examined sufficiently in healthy people and not at all in patients with COPD.25 In addition, few studies have assessed the moderating effects of depressed mood on changes in health outcomes from such treatments in patients with COPD. We previously reported the main results from an experimental study evaluating three dyspnea self-management (DM) programs, two of which included additive doses of supervised exercise in addition to a standard program of individualized education and home-based walking for patients with COPD.26 We found that the effect on dyspnea severity, exercise performance, and health-related quality of life was largely dependent on the “dose” of supervised exercise (no, four, or 24 sessions) in that subjects who received the extended training outperformed the other two groups. In this article, we report on the effects of the three DM programs on depressed mood and present subgroup analyses of the moderating effects of baseline depression risk on improvement in the primary study outcome variables of dyspnea severity, exercise performance, and social and physical functioning. METHOD Design The data used for this secondary analysis are from a randomized clinical trial of the three DM programs. The study methods have been reported in-depth elsewhere26 and are therefore described only briefly in this article. After baseline testing, subjects were randomly assigned to one of three treatment groups (DM, DM plus four supervised exercise sessions, or DM plus 24 supervised exercise sessions; see “Interventions” later in this section). Outcomes were measured at baseline and at 2 months. Of the 115 subjects who were randomly assigned to study groups, 12 dropped out for various reasons, including illness, disinterest, and transportation problems, leaving 103 subjects who completed the 2-month evaluation. The study protocol was approved by the institutional review board, and each subject gave informed written consent. Psychosomatics 46:5, September-October 2005
Subjects Subjects were recruited by advertisements and referrals from numerous sources, including physicians’ offices and Better Breathers Clubs of the American Lung Association. Entry criteria were age ⬎40 years, confirmation of a diagnosis of moderate to severe COPD (i.e., FEV1 ⬍60% of the predicted level or a ratio of FEV1 to forced vital capacity ⬍60%) with clinical stability for at least 1 month, no participation in formal exercise training or pulmonary rehabilitation in the previous year, and absence of other active symptomatic diseases that would interfere with exercise (e.g., cancer, coronary artery disease, heart failure, psychiatric illness). Interventions The basic DM program included three components: individual education and demonstration of strategies for self-management of dyspnea, an individualized home-based walking prescription, and exercise selfmonitoring that included use of a pedometer and exercise log (see Appendix 1 for more details). Subjects in the group who received DM plus four supervised exercise sessions received the basic DM program plus a total of four nurse-supervised treadmill exercise sessions once every other week for 2 months. The goal of the exercise sessions was steady-state symptom-limited exercise consisting of continuous walking for as long as 30 minutes at the endurance treadmill test workload. Subjects in the group who received DM plus 24 supervised exercise sessions received the basic DM program plus 24 nurse-supervised treadmill exercise sessions three times per week over 2 months. The exercise sessions were identical to those received by the subjects who received four supervised exercise sessions. Pulmonary Function Testing Subjects performed spirometry 15–30 minutes after receiving two puffs of albuterol administered by means of a spacer (Aerochamber; Monaghan, Plattsburg, N.Y.). Spirometry was performed with a 10-liter water-seal spirometer (Collins Medical, Braintree, Mass.) according to American Thoracic Society criteria.27 Baseline lung volumes (helium dilution method), maximum voluntary ventilation, single-breath diffusion capacity for carbon monoxide, and residual volume over total lung capacity were measured by using a body plethysmograph (Collins Plus Body Plethysmography System; Collins Medical, Braintree, Mass.). http://psy.psychiatryonline.org
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Depressed Mood in COPD Measurements Depressed mood The Center for Epidemiological Studies Depression (CES-D) Scale is a 20-item self-administered instrument developed for use in epidemiological studies of depressive symptoms in the general population.28 The cutoff score of 16 was identified as the 80th percentile of scores in the general population and is used to identify individuals at high risk for depression. This cutoff score was shown to have a sensitivity of 73% and specificity of 84% for detecting depression in hospitalized, medically ill, elderly patients.29 In this study, subjects were classified as having a higher level of depressed mood and/or as being at high risk for depression if they scored above 15 on the CES-D Scale. Cronbach alpha for the CES-D Scale in this study was 0.85. Dyspnea with activities of daily living The Chronic Respiratory Questionnaire (CRQ) is an interviewer-administered disease-specific quality-of-life questionnaire for patients with COPD that includes 20 questions assessing four health status domains.30 The dyspnea subscale (CRQ-D) measures the severity of dyspnea in the past 2 weeks during five activities of daily living (ADLs) chosen by the patient as being important in his or her daily life. Cronbach alpha for the CRQ-D in this study was 0.73. Exercise performance Subjects performed a symptomlimited endurance treadmill test according to a previously reported protocol.26 Each subject performed the endurance treadmill test at a workload one level below the maximum workload completed during their baseline incremental test. Standard physiological measurements were made during the endurance treadmill test (Sensormedics 2900, Yorba Linda, Calif.), and all equipment was calibrated immediately before each test. Self-reported functioning The physical and social functioning scales of the Medical Outcomes Study Short Form Health Survey (SF-36) were used.31 The SF-36 is a valid and reliable measure of self-reported functioning for patients with COPD.31,32 Cronbach alphas in this study were 0.86 and 0.70 for the physical and social functioning scales, respectively. Statistical Analysis Results are reported as means and standard deviations. Univariate analyses of covariance were performed on the 404
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data for each dependent variable by treatment group (i.e., DM, DM plus four exercise sessions, and DM plus 24 exercise sessions) and depression risk group (subjects with CES-D Scale scores ⬎15 and subjects with CES-D Scale scores ⱕ15) while controlling for age, disease severity, gender, antidepressant use, and baseline scores for the respective variable. This design allowed for testing of the main effects of treatment group and depression risk and the interaction of the two factors. If the interaction was significant, post hoc pair-wise contrasts were performed. A p value of ⬍0.05 was considered significant. All analyses were conducted by using SPSS 12.0 for Windows (SPSS, Inc., Chicago). RESULTS A total of 115 subjects were randomly assigned to treatment groups. Four subjects from each treatment group dropped out before the first evaluation at 2 months. Three additional subjects had unusable data on at least one of the outcome variables, leaving 100 subjects with complete data. Demographic and pulmonary function data are presented in Table 1, and baseline scores by treatment group and depression risk findings are presented in Table 2. The overall study group had significant improvement in CES-D Scale scores from baseline (mean⳱13.3, SD⳱8.9) to 2 months (mean⳱12.0, SD⳱9.5) (F⳱4.5, df⳱1, 97, p⳱0.04); no differences between the treatment groups were found. Subgroup analyses of the 36 subjects with a CES-D Scale score ⬎15 at baseline also showed a significant time effect from baseline (mean⳱23.1, SD⳱6.1) to 2 months (mean⳱20.0, SD⳱11.1) (F⳱7.1, df⳱1, 33, p⳱0.002), with no group-by-time differences (F⳱0.06, df⳱2, 33, p⳱0.94). The number of subjects who were at high risk for depression was equally distributed across the three treatment groups (v2⳱2.3, df⳱2, p⳱0.32). Only four of the 36 subjects at high risk for depression (11%) reported taking an antidepressant at study entry. Figure 1, Figure 2, Figure 3, and Figure 4 show the improvements in dyspnea with ADLs, exercise performance, social functioning, and physical functioning measures, respectively, from baseline to 2 months for the three treatment groups according to depression risk (baseline CES-D Scale scores). There was a significant interaction of treatment group and depression risk in improvements in dyspnea with ADLs (F⳱3.7, df⳱2, 89, p⳱0.03). Subjects who were at higher risk for depression at baseline who received DM plus 24 exercise sessions had substantially Psychosomatics 46:5, September-October 2005
Nguyen and Carrieri-Kohlman greater reductions in dyspnea (mean change⳱6.8, SD⳱1.4), compared to those who received either DM (mean change⳱1.3, SD⳱0.9; t⳱5.0, df⳱25, p⳱0.03) or DM plus four exercise sessions (mean change⳱1.1, SD⳱1.6; t⳱4.9, df⳱19, p⳱0.01). For subjects who were at low risk for depression, DM plus four exercise sessions was comparable to DM plus 24 exercise sessions in im-
TABLE 1.
Characteristics of Patients With Chronic Obstructive Pulmonary Disease (Nⴔ100) in a Study of the Effects of Three Dyspnea Self-Management Programs on Depressed Mood
Characteristic Gender Female Male Age (years) Forced expiratory volume in 1 second (FEV1) (liters) FEV1 (% of predicted level) FEV1/forced vital capacity (%) Maximum voluntary ventilation (% of predicted level) Residual volume/total lung capacity (%) Diffusion capacity of carbon monoxide (% of predicted level)
TABLE 2.
proving dyspnea (t⳱1.9, df⳱43, p⳱0.13) but was better than DM (t⳱3.1, df⳱41, p⳱0.02). There were no significant main effects of depression risk on the improvements in any of the three remaining outcomes of endurance exercise, social functioning, and physical functioning. However, subjects with higher depression risk were more likely to report a greater increase in social functioning than those
Patients Who Received Dyspnea Self-Management (DM)
Patients Who Received DM Plus Four Supervised Exercise Sessions
Patients Who Received DM Plus 24 Supervised Exercise Sessions
N
%
N
%
N
%
15 19 Mean 65.8
44 56 SD 9.0
18 14 Mean 67.1
56 44 SD 7.7
22 12 Mean 66.2
65 35 SD 6.4
1.1 43.1 39.7
0.38 18.7 14.2
1.2 48.5 43.4
0.31 12.8 8.7
1.0 43.7 43.6
0.30 9.9 11.2
39.2 53.7
16.1 9.8
46.4 53.0
15.5 10.0
41.0 55.4
11.8 10.6
63.3
21.9
68.3
22.0
64.4
17.6
Baseline Dyspnea, Exercise Endurance, and Social and Physical Functioning Scores in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa Dyspnea With Activities of Daily Livingb
Treatment Group and Depression Risk Dyspnea self-management (DM) Patients with CES-D Scale score ⱕ15 (N⳱19) Patients with CES-D Scale Score ⬎15 (N⳱15) DM plus four supervised exercise sessions Patients with CES-D Scale score ⱕ15 (N⳱23) Patients with CES-D Scale score ⬎15 (N⳱9) DM plus 24 supervised exercise sessions Patients with CES-D Scale score ⱕ15 (N⳱22) Patients with CES-D Scale score ⬎15 (N⳱12)
Exercise Endurance Time (minutes)c
Social Functioning Scored
Physical Functioning Scoree
Mean
SD
Mean
SD
Mean
SD
Mean
SD
16.8 14.9
5.9 5.1
7.4 6.7
4.0 7.2
69.1 51.7
23.3 24.9
36.2 30.7
15.9 21.3
17.9 16.0
3.9 4.8
6.2 8.0
3.2 6.7
84.2 47.2
15.6 16.3
43.0 32.2
17.4 13.8
16.7 14.3
5.2 3.9
6.6 6.7
4.3 4.2
76.1 44.8
23.1 14.6
35.0 24.6
18.8 11.8
CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. Measured with the dyspnea subscale of the Chronic Respiratory Questionnaire.30 Higher scores indicate better health status. c Measured with a symptom-limited endurance treadmill test. Higher times indicate better health status. d Measured with the social functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31 Higher scores indicate better health status. e Measured with physical functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31 Higher scores indicate better health status. a
b
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Depressed Mood in COPD who were not at risk, regardless of the treatment group, although the difference did not reach significance (F⳱2.0, df⳱2, 89, p⳱0.17). DISCUSSION In subjects with moderate to severe COPD: 1) all three versions of a 2-month program of dyspnea self-management equally and significantly improved depressed mood both in a subset of subjects at high risk for depression and in the overall study group, 2) those at high risk for depression at study entry had greater reductions in dyspnea from intensive supervised exercise training (DM plus 24 supervised exercise sessions) than from the other two programs (DM and DM plus four supervised exercise sessions), and 3) there were no significant main effects of depression risk on improvements in exercise performance, social functioning, and physical functioning. The CES-D Scale, which has fewer somatic items compared to other available instruments, was used in this study to assess the presence of depressed mood, not to FIGURE 1.
Change in Dyspnea With Activities of Daily Living (ADL) in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
make a clinical diagnosis of depression. Subjects with a score of 15 or higher at baseline were considered at high risk for clinical depression.33 According to this criterion, 36% of the subjects in our study were considered at risk for depression at baseline. This prevalence of depression symptoms appears to be congruent with other research findings, but it is likely an underestimate, because depression may deter COPD patients from participating in research studies.1,24 Of greater importance, only four subjects at risk for clinical depression were medically treated at baseline. This finding parallels that of an earlier study in which a mere 6% of oxygen-dependent COPD patients who were classified as depressed according to the Geriatric Depression Scale were taking an antidepressant.7 These observations are concerning yet not surprising, given that one recent national study in the United States reported that patients with a diagnosis of depression received only approximately one-half of the recommended level of care.34 On average, the patients recruited for this study, which was based at a major academic medical center, did not exhibit high levels of depressive mood at baseline yet were still able to reduce their CES-D Scale scores with all three FIGURE 2.
Change in Exercise Endurance Time in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa Dyspnea self-management (DM)
DM plus 24 exercise sessions
DM plus four exercise sessions
10
DM plus 24 exercise sessions 14
8
p=0.03 p=0.01
6 p=0.02
4
2
12 10 8 6 4 2
0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the dyspnea subscale of the Chronic Respiratory Questionnaire.30
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Mean Change in Exercise Endurance Time (minutes)b
Mean Change in Dyspnea With ADL Scoreb
Dyspnea self-management (DM) DM plus four exercise sessions
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0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with a symptom-limited endurance treadmill test.
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Nguyen and Carrieri-Kohlman DM programs. The DM programs in our study were not designed as a treatment for depression per se; however, certain components such as improved knowledge about strategies to manage dyspnea, exercise, support from and contact with the nurse, which enhanced feelings of control over their symptoms,35 may have had a positive effect on their mood. Although the specific individual contributions from each of these components to improvement in depressed mood cannot be ascertained in this study, the literature suggests that exercise performed on a regular basis has a mild antidepressant effect.36 The optimal treatment for depression in patients with COPD has not been established. Although one study showed positive effects of pharmacotherapy for clinically depressed COPD patients,37 few other studies have corroborated these findings.38 The limited success in treating depression is not unique to patients with COPD; it continues to be a vexing challenge even in coronary heart disease, where substantial attention and research have been devoted to the testing of interventions to reduce the effect of depression on morbidity and mortality.39,40 Similar to our study, one recent study found signifi-
cantly greater reduction in depressed mood, as measured by the CES-D Scale, in patients with COPD who received pulmonary rehabilitation, compared with those who received usual care.21 However, these effects have not been consistent. Several other studies that tested exercise training alone,41 a similar pulmonary rehabilitation program,42 and a dyspnea education and skills training intervention43 have not shown improvements in depressed mood as measured by the CES-D Scale. The lack of improvement in the study by Etnier and Berry41 may have been due to a floor effect, but this explanation did not hold true for the other two studies. It is interesting to note that in other studies, the Beck Depression Inventory (BDI)44 and Hospital Depression Scale20 have been used to measure the effects on depression of short-term pulmonary rehabilitation and the Geriatric Depression Scale45 has been used to measure the effects on depression of brief cognitive behavior therapy for COPD patients. Investigators in these studies have reported notable changes in depression. One small study from Brazil recently showed the additive effects of psychotherapy above pulmonary rehabilitation alone in im-
FIGURE 3.
FIGURE 4.
Change in Social Functioning in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
Dyspnea self-management (DM) DM plus four exercise sessions
Mean Change in Social Functioning Scoreb
DM plus 24 exercise sessions
20
15
10
5
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the social functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31
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Mean Change in Physical Functioning Scoreb
Dyspnea self-management (DM) DM plus four exercise sessions 25
0
Change in Physical Functioning in Patients With Chronic Obstructive Pulmonary Disease and High and Low Center for Epidemiological Studies Depression (CES-D) Scale Scores in Three Dyspnea Self-Management Programsa
DM plus 24 exercise sessions 12 10 8 6 4 2 0
(N=15) (N=9) (N=12) Subjects With CES-D Scale Score >15
(N=19) (N=23) (N=22) Subjects With CES-D Scale Score ≤15
a CES-D Scale scores ⱕ15 indicate low risk for depression; CES-D Scale scores ⬎15 indicate high risk for depression. b Measured with the physical functioning scale of the Medical Outcomes Study 36-item Short-Form Health Survey.31
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Depressed Mood in COPD proving depression.46 In that study, patients with COPD who received 12 psychotherapy sessions in addition to a standard pulmonary rehabilitation program showed significantly greater improvement in depression (as measured by the BDI), compared to subjects who received rehabilitation alone. Although the 36 subjects in the current study who were at high risk for depression at baseline had significant reductions in their CES-D Scale scores after 2 months, they remained at high risk for depression. The use of concurrent psychotherapy with self-management interventions such as the DM program for patients with COPD and depression holds tremendous promise and will need to be tested. Subjects at lower risk for depression (those with CES-D Scale scores ⱕ15) in the groups that received DM and DM plus four exercise sessions tended to have improvement in dyspnea with ADLs that was, respectively, within the margins for and twice that of the criterion for a minimal clinically important difference (MCID) (for the CRQ-D, the MCID criterion is 2.5 points).47 In contrast, subjects who were at high risk for depression in these two treatment groups had minimal improvements in their dyspnea. These findings, coupled with the observed change in dyspnea that exceeded three times the MCID in subjects who had CES-D Scale scores ⬎15 and who received intensive supervised exercise training, suggest that programs with minimal supervised exercise may be inadequate for improving dyspnea in patients who have higher levels of depressed mood. For subjects who are at low risk for depression, DM plus four supervised exercise sessions may be adequate if the goal is to achieve clinically meaningful improvements in dyspnea. We are not aware of any other published studies that have documented the moderating effects of depressed mood on improvements in dyspnea with different doses of supervised exercise in patients with COPD. Depression can negatively affect adherence to treatments48 such as exercise and, therefore, may reduce the degree of improvements in health outcomes, as has been observed in patients with cardiac disease49–51 and in functionally disabled older patients.52 Adherence to the supervised exercise sessions was high in the group that received DM plus four exercise sessions (93%) and in the group that received DM plus 24 exercise sessions (100%).26 However, an analysis of both supervised and independent walking sessions showed that the groups that received DM and DM plus four exercise sessions logged fewer average weekly walking sessions
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than the group that received DM plus 24 exercise sessions during the 2 months.53 The intensive supervision likely served as a strong motivating force for consistent exercise and provided opportunities for subjects at high risk for depression to practice their dyspnea management strategies in a safe setting. Depression has also been shown to be a strong moderator of other health behaviors, such as smoking. Depressed smokers have been found to be 40% less likely to successfully quit smoking, compared with nondepressed smokers.54 Earlier cross-sectional studies showed that depressed mood was associated with social functioning but not physical functioning in patients with COPD.6,8 Subjects with higher CES-D Scale scores at baseline tended to have greater improvement in social functioning, compared to subjects who had lower CES-D Scale scores, regardless of their treatment group. This pattern suggests that if the goal is to improve social functioning in patients with COPD who have higher levels of depressed mood, all three versions of the DM program can be recommended. We did not observe any moderating effects of depressed mood on changes in exercise performance or physical functioning. It is more likely that nonpsychological factors have a greater influence than depression on exercise and physical functioning.45 CONCLUSIONS All three versions of a dyspnea self-management program significantly improved depressed mood in patients with moderate to severe COPD. Patients who were at high risk for depression at study entry benefited greatly in terms of greater reductions in dyspnea if they received more intensive supervised exercise training along with the dyspnea self-management program. Our findings will need to be replicated in a larger study that employs a factorial design and includes sufficient numbers of patients with depressed mood and/or a diagnosis of depression.55 Nonetheless, we recommend that self-management programs for patients with COPD screen for depression and tailor exercise regimens accordingly, e.g., providing more supervision for patients with depressed mood/depression, in order to maximize symptomatic improvements. The study was funded by National Institute of Nursing Research grant R01-NR02131-08 to Dr. Carrieri-Kohlman.
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APPENDIX 1.
Components of a Dyspnea Self-Management Program for Patients With Chronic Obstructive Pulmonary Disease
Component
Description
Individualized education, four sessions (3 hours total)
Topics included 1) identification of the patient’s triggers for dyspnea and previous self-care strategies for managing these triggers; 2) proper use of medications; 3) specific strategies for managing dyspnea, including breathing retraining, distraction, relaxation, and adjustment of oxygen with exercise; 4) benefits of homebased walking and integration of home-based walking into the patient’s lifestyle, with discussion of specific ways to overcome barriers. Patients were instructed to walk at least four times a week for a minimum of 20 minutes per session at their maximum pace so that they felt at the end of the walk that they could not have gone further. Patients were given a pedometer and daily logs. They recorded the time and distance walked and the level of dyspnea reached at the end of the walk using a 0–10 modified Borg scale.
Home-based walking exercise prescription Exercise self-monitoring
References
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