Bhandari, Neha Jain MD; Jain, Tarun MD; Marolda, Corliss RN; ZuWallack, Richard L. MD
Chronic obstructive pulmonary disease (COPD) often has prominent systemic effects and comorbidities.1 The prevalence rates of anxiety and depression symptoms in stable COPD are very high and vary widely among studies, ranging from approximately 10% to 80%.2–6 This wide range in prevalence rates undoubtedly relates, in part, to the different screening instruments and methods used to identify anxiety and depression. Psychological comorbidity is not only prevalent, but it is also associated with adverse outcomes in COPD. Concurrent anxiety and depression are related to impaired quality of life2 and predict treatment failure in obstructive lung disease.3 Concurrent depression is associated with increased risks of hospital readmission and mortality.4,5 Despite the high prevalence rates and the association with increased morbidity and mortality, the symptom burdens of anxiety and depression go frequently unrecognized and undertreated in COPD.
Pulmonary rehabilitation, regarded as an integral component in the management of COPD,6 leads to improvement across a wide spectrum of outcomes of importance to patients including dyspnea, exercise performance, and quality of life.7 In addition, a systematic review indicates that pulmonary rehabilitation programs that provide supervised exercise, education, and psychosocial support reduce anxiety and depression.8
The Hospital Anxiety and Depression Scale (HADS),9 an easy-to-use, 14-item, self-administered instrument that screens for the presence of anxiety and depression,10 has been used increasingly in studies of patients with COPD. Janssen et al11 have recently demonstrated the HADS to be a useful instrument for screening for anxiety and depression symptoms in COPD patients referred to pulmonary rehabilitation. Further adding to the desirability of this questionnaire as an evaluative instrument is the recent demonstration of the minimal clinically important difference (MCID) for change in its score, which is around 1.5 units in COPD patients.12
Pulmonary rehabilitation results in significant decrease in anxiety and depression symptoms in patients with COPD.13 Since the MCID is now established for changes in HADS anxiety and depression scores in COPD, we reviewed our pulmonary rehabilitation outcomes data to determine whether changes in HADS anxiety and depression met the MCID threshold.
This was a retrospective analysis of demographic, disease severity, and outcome data from a single outpatient, hospital-based pulmonary rehabilitation center. Institutional review board approval for this analysis was obtained. Records from patients enrolling in our pulmonary rehabilitation program between December 2001 and December 2009 were reviewed. Data were analyzed if patients had at least 1 outcome determination at baseline, had a clinical diagnosis of COPD at the time of entry into the program, and had a forced expiratory volume in 1 second (FEV1) < 80% predicted. The latter corresponds to Global Initiative for Chronic Obstructive Lung Disease (GOLD) moderate, severe, and very severe spirometric severity ratings.14
Pulmonary rehabilitation at our center includes a clinical evaluation by a pulmonologist followed by patient-centered self-management education, exercise training, and psychosocial support administered by 2 registered nurses. The program typically involves 16 approximately 3-hour sessions given twice weekly over 8 weeks. If classes are missed, the program is generally extended until all sessions are completed. Self-management education is administered one-on-one and in classroom formats. Exercise training includes upper and lower extremity endurance training on the cycle ergometer, treadmill, and arm ergometer, classroom calisthenics, and lightweight training. Psychosocial support includes stress reduction and relaxation techniques.
Outcomes were measured immediately before and after pulmonary rehabilitation by the same staff person. These included the following:
* The 6-Minute Walk Test. For this, patients were instructed to walk as far as possible up and down a corridor over a 6-minute period. Standardized encouragement was given, and supplemental oxygen was provided when needed. Those patients using supplemental oxygen carried their own tank or device. Rest stops were permitted.
* The number of unsupported arm lifts in 60 seconds. For this test, the patient sat on a chair and was instructed to raise a wooden dowel from waist level to above the head repeatedly and as rapidly as possible over a 1-minute period. The method for this test has been described previously and has demonstrated responsiveness to the pulmonary rehabilitation intervention.15
* The self-reported Chronic Respiratory Disease Questionnaire (CRQ-SR).16 The questionnaire has 4 dimensions: dyspnea (5 items), fatigue (4 items), emotion (7 items), and mastery (4 items), as well as a total summary score. Each question is graded on a 7-point scale, ranging from 1 to 7. Lower scores indicate greater impairment; a 0.5 unit per item change is considered clinically meaningful. We used the total CRQ-SR score in our analysis.
* Anxiety and depression scores from the HADS.9 This validated self-assessment questionnaire screens for anxiety and depression in both hospitalized and primary care settings.10 The questionnaire has 2 seven-item scales, 1 rating anxiety, and 1 rating depression. Each rating can range from 0 (least anxiety or depression) to 21 (greatest anxiety or depression). We used scores ≥10 to indicate increased anxiety or depression symptoms.11 The MCID in COPD patients is approximately 1.5 units.12
Demographic and disease severity data are presented as means ± standard deviations. We defined completion of pulmonary rehabilitation as completion of the required sessions, as determined by the rehabilitation team. Some of the completers did not, or could not, return for outcome analysis. Predictors of completion of pulmonary rehabilitation were analyzed using univariate and multivariate logistic regression techniques (SAS, proc LOGISTIC). Completers and noncompleter groups were also compared using unpaired t tests and χ2 analyses. Pearson correlations were used to compare relationships between baseline values and changes in outcomes. Regression techniques (SAS proc REG and proc GLM) were used to evaluate mediator and moderator effects.
Data from 366 patients who met inclusion criteria were available for analysis. Of these, 257 (70%) completed the program, and postrehabilitation outcome data were available on 235 (64%). Five of the noncompleters died during pulmonary rehabilitation; the remainder dropped out for various reasons, often because of the development of an intercurrent illness or because of a change of mind regarding continued participation. The mean number of sessions attended in the completers was 15.0 ± 3.2 sessions.
Table 1 provides baseline characteristics of the entire sample, and those who completed and did not complete the program; 51% were males. Using GOLD spirometric severity classification, 41% were moderate, 37% were severe, and 22% were very severe. Supplemental oxygen was used by 36%. The mean HADS anxiety and depression scores were 6.6 ± 4.0 and 6.0 ± 3.8, respectively. Abnormal HADS anxiety scores were present in 25%, and abnormal HADS depression scores were present in 17% of patients beginning pulmonary rehabilitation.
Males had lower baseline HADS anxiety scores than females (5.8 ± 3.8 vs 7.4 ± 3.0, P < .0001), although there was no male-female difference in depression (5.9 ± 3.8 vs 6.0 ± 3.8, respectively, P = .80). Supplemental oxygen use was associated with higher depression scores (7.1 ± 4.1 vs 5.3 ± 3.4, P < .0001) but not with anxiety scores (7.0 vs 6.3, P = .11).
Age, gender, and FEV1 (expressed either as percent-predicted or GOLD severity rating) were not related to completion of pulmonary rehabilitation. However, a shorter 6-minute walk distance, fewer arm lifts per minute, lower CRQ total score, and higher HADS anxiety and depression scores were all associated with noncompletion of the program. Seventy-four percent of those with normal anxiety scores versus 59% with abnormal scores completed outpatient pulmonary rehabilitation (OPR) (P = .006). Completion percentages were 73% versus 56% for normal and abnormal depression scores, respectively (P = .007). In stepwise logistic regression with the above predictor variables entered, a shorter 6-minute walk distance and higher HADS depression scores were significantly related to noncompletion of OPR.
Table 2 lists the pre- to postrehabilitation changes in outcome measures. All outcomes showed highly significant (P < .0001) improvement from baseline. Using data from only those patients who eventually completed pulmonary rehabilitation, percent improvements over baseline were as follows: 6 minute walk distance (18%), arm lifts (30%), CRQ total score (22%), HADS anxiety (16%), and HADS depression (27%). The MCID for improvement was surpassed in 41% and 46% of patients for HADS anxiety and depression, respectively. Of those with abnormal anxiety scores at baseline (n = 44), 91% surpassed the MCID, while for those with abnormal depression scores (n = 30), 93% surpassed the MCID. The percentage of patients with abnormal anxiety scores and abnormal depression scores decreased to 9% and 6%, respectively, in those completing pulmonary rehabilitation having final outcome analysis. Using an increase in score of ≥ 1.5 units to define MCID worsening, clinically meaningful increases in anxiety and depression were observed in 16% and 11%, respectively.
Our review of COPD patients undergoing pulmonary rehabilitation demonstrated the following: (1) anxiety and depression are prevalent in COPD patients referred to pulmonary rehabilitation; (2) depression and anxiety are significant predictors of noncompletion of pulmonary rehabilitation; and (3) pulmonary rehabilitation leads to substantial and clinically meaningful changes in both anxiety and depression.
Using HADS scores of 10 or greater to define abnormality, we found relatively high prevalence rates of anxiety and depression in COPD patients enrolling in our pulmonary rehabilitation program: 25% had abnormal anxiety scores and 17% had abnormal depression scores. While these abnormalities suggest an increased burden of psychological symptoms, they do not necessarily imply all had clinical anxiety or depression. The prevalence rates of abnormal HADS scores are similar to those observed in a review of 701 COPD patients entering pulmonary rehabilitation in the Netherlands. In this review, abnormal HADS scores for anxiety were present in 32% and for depression in 27%. These studies underscore the desirability of screening for these comorbid conditions in COPD patients entering pulmonary rehabilitation.
An interesting finding is the relationship between these psychological variables and completion or noncompletion of pulmonary rehabilitation. Overall, 70% of our patients finished pulmonary rehabilitation. This completion rate is remarkably similar to the 69% reported by Garrold et al17 in an analysis of success and failure in pulmonary rehabilitation. While we do not maintain records on why our patients drop out, 5 of the noncompleters died during rehabilitation. Probably most of the remaining dropouts were due to the development of a respiratory exacerbation or were from a change of mind regarding continued participation.
In our study, a lower 6-minute walk distance was a significant predictor of noncompletion of pulmonary rehabilitation. The reasons behind this effect are not entirely clear, but the walk test distance is predictive of mortality and morbidity in COPD,18,19 including exacerbations.20 These changes may mediate decreased adherence with continuing pulmonary rehabilitation. In addition to a decreased 6-minute walk distance, anxiety and depression were significant predictors of noncompletion of pulmonary rehabilitation. Our findings are in accord with Garrold et al17 (cited previously), who also determined that depression was predictive of noncompletion of pulmonary rehabilitation.
Not only did anxiety and depression scores on the HADS questionnaire improve significantly with pulmonary rehabilitation, but the threshold for the MCID was surpassed in a sizeable percentage of patients: reductions in HADS anxiety and/or depression scores by more than 1.5 units were present in more than 40% of patients. Since some patients had very low anxiety or depression scores at enrollment, a ceiling effect was undoubtedly present, with there being no room for improvement. Indeed, for those with abnormal anxiety or depression scores, more than 90% had improvements that met or exceeded the MCID. Thus, pulmonary rehabilitation appears to be of considerable benefit in relieving anxiety and depression. How it does so remains to be determined. Conversely, increases surpassing the MCID for anxiety and depression were seen in 16% and 11%, respectively.
We were not able to demonstrate a significant association between anxiety and depression scores on the HADS and spirometric abnormalities. This indicates that this aspect of COPD severity and severity of depression and anxiety, that is, COPD patients with GOLD class 1–4, experience comparable levels of psychological distress. The findings from our study are in accordance with other studies of COPD patients undergoing pulmonary rehabilitation. In patients with COPD, pulmonary rehabilitation induces important changes in anxiety and depression independent of changes in dyspnea and quality of life.21
A limitation of our study is that it is a retrospective review of data with a before-after type of analysis and no control group for comparison. Certainly factors other than the pulmonary rehabilitation intervention may have affected the self-report HADS scores. Without data from a control group, firm conclusions cannot be made. However, strengths of the study include the use of reliable outcome measures and the focus on clinically meaningful change. Also, our study, with its relatively large sample size and a “real world” setting, suggests that pulmonary rehabilitation leads to clinically meaningful changes in anxiety and depression symptoms in patients with COPD.
1. Fabbri LM, Luppi F, Beghe B, Rabe KF. Complex chronic comorbidities of COPD. Eur Respir J. 2008;31:204–212.
2. Cully JA, Graham DP, Stanley MA, et al. Quality of life in patients with chronic obstructive pulmonary disease and comorbid anxiety or depression. Psychosomatics. 2006;47:312–319.
3. Dahlen I, Jansen C. Anxiety and depression are related to the outcome of emergency treatment in patients with obstructive pulmonary disease. Chest. 2002;122:1633–1637.
4. Gudmundsson G, Gislason T, Janson C, et al. Risk factors for rehospitalisation in COPD: role of health status, anxiety and depression. Eur Respir J. 2005; 26:414–419.
5. Ng TP, Niti M, Tan WC, Cao Z, Ong KC, Eng P. Depression symptoms and chronic obstructive pulmonary disease. Arch Intern Med. 2007;167:60–67
6. Celli BR, MacNee W, Agusti A, et al. Standards for the diagnosis and treatment of patients with COPD: a summary of the ATS/ERS position paper. Eur Respir J. 2004;23:932–946.
7. Ries AL, Bauldoff GS, Carlin BW, et al. Pulmonary rehabilitation: joint ACCP/AACVPR evidence-based clinical practice guidelines. Chest. 2007;131:4S–42S.
8. Coventry PA, Hind D. Comprehensive pulmonary rehabilitation for anxiety and depression in adults with chronic obstructive pulmonary disease: systemic review and meta-analysis. J Psychosom Res. 2007;63:551–565.
9. Zigmond AS, Snaith RP. The Hospital Anxiety and Depression Scale. Acta Psychiatr Scand. 1983;6:361–370.
10. Bjelland I, Dahl AA, Haug TT, Neckelmann D. The validity of the Hospital Anxiety and Depression Scale: an updated literature review. J Psychosom Res. 2002;52:69–77.
11. Janssen DJA, Spruit MA, Leue C, et al. Symptoms of anxiety and depression in COPD patients entering pulmonary rehabilitation. Chron Respir Dis. 2010;7:147–157.
12. Puhan MA, Frey M, Buchi S, Schunemann HJ. The minimal important difference of the Hospital Anxiety and Depression Scale in patients with chronic obstructive pulmonary disease. Health Qual Life Outcomes. 2008;6:46.
13. Coventry PA. Does pulmonary rehabilitation reduce anxiety and depression in chronic obstructive pulmonary disease? Curr Opin Pulm Med. 2009;15:143–149.
14. Global Initiative for Chronic Obstructive Lung Diseases. Executive summary: global strategy for diagnosis, management, and prevention of COPD. http://www.goldcopd.com
. Updated 2009. Accessed September 7, 2010.
15. Normandin EA, McCusker C, Connors ML, Vale F, Gerardi D, ZuWallack RL. An evaluation of two approaches to exercise conditioning in pulmonary rehabilitation. Chest. 2002;121:1085–1091.
16. Williams JEA, Singh SJ, Sewell L, Guyatt GH, Morgan MDL. Development of a self-reported Chronic Respiratory Questionnaire (CRQ-SR). Thorax. 2001;56:954–959.
17. Garrold R, Marshall J, Barley E, Jones PW. Predictors of success and failure in pulmonary rehabilitation. Eur Resp J. 2006;27:788–794.
18. Gerardi DA, Lovett L, Benoit-Connors ML, Reardon JA, ZuWallack RL. Variables related to increased mortality following outpatient pulmonary rehabilitation. Eur Respir J. 1996;9:431–435.
19. Bowen JB, Votto JJ, Thrall RS, et al. Functional status and survival following pulmonary rehabilitation. Chest. 2000;118:697–703.
20. Kessler R, Faller M, Fourgaut G, Mennicier B, Weitzenblum E. Predictive factors of hospitalization for acute exacerbation in a series of 64 patients with chronic obstructive pulmonary disease. Am J Respir Crit Care Med. 1999;159:158–164.
21. Paz-Diaz H, Montes de Oca M, Lopez JM, Celli BR. Pulmonary rehabilitation improves depression, anxiety, dyspnea and health status in patients with COPD. Am J Phys Med Rehabil. 2007;1:30–36.
anxiety; Chronic Respiratory Disease Questionnaire (CRQ-SR); COPD; depression; Hospital Anxiety and Depression Scale (HADS); Minimal Clinically Important Difference (MCID); Pulmonary Rehabilitation; Six Minute Walk Test
© 2013 Lippincott Williams & Wilkins, Inc.