Improving outcomes for COPD patients with mild-to-moderate anxiety and depression: a systematic review of cognitive behavioural therapy
- COVENTRY Peter A., GELLATLY Judith L.
- Journal article citation:
- British Journal of Health Psychology, 13(3), September 2008, pp.381-400.
Anxiety and depression are highly prevalent in patients with chronic obstructive pulmonary disease (COPD) and are associated with lower levels of self-efficacy, impaired health status, poorer treatment outcomes and reduced survival following emergency admission. Cognitive behavioural therapy (CBT) may be effective for treating anxiety and depression in COPD patients but evidence for this is uncertain. A systematic review of controlled trials that evaluated the effectiveness of CBT for treating mild-to-moderate anxiety or depression in adults with clinically stable COPD. Ovid electronic bibliographic databases were searched from inception to May 2006; all content held by the Cochrane Library Issue 3, 2006 was also searched. One small randomized controlled trial (RCT) of moderate quality showed that CBT, when given with exercise training and education, was associated with large and significant treatment effects for both anxiety and depression. Additionally, a larger RCT of higher quality demonstrated that CBT, when given with exercise and education, was associated with large and significant treatment effects for depression, but not for anxiety. No other included study reported significant reductions in either anxiety or depression in COPD patients given CBT. There is only limited evidence that CBT, when used with exercise and education, can contribute to significant reductions in anxiety and depression in COPD patients. There is scope for a well-powered RCT to evaluate the effectiveness and acceptability of CBT among this patient population.
- Extended abstract:
COVENTRY Peter A.; GELLATLY Judith L.;
Improving outcomes for COPD patients with mild-to-moderate anxiety and depression: a systematic review of cognitive behavioural therapy.
Journal citation/publication details
British Journal of Health Psychology, 13(3), September 2008, pp.381-400.
Only four randomised controlled trials (RCTs) were identified of the use of cognitive behavioural therapy (CBT) to address mild to moderate anxiety and depression in patients with chronic obstructive pulmonary disease. One small trial of moderate quality showed large and significant treatment effects for both anxiety and depression when CBT was used in association with exercise training and education. Another larger trial showed large effects for depression but not anxiety. The remaining trials did not report significant effects.
COPD is a leading cause of ill health, disability and death, with as many as three million UK adults potentially affected if smoking rates are used to model prevalence rates. Adverse psychological effects, including depression and anxiety, are common but little attention has been paid in existing reviews to the effectiveness of CBT in treating these problems in COPD patients.
What sources were used?
The following databases were searched: British Nursing Index; CINAHL (Cumulative Index to Nursing and Allied Health Literature); the Cochrane Library (Issue 3, 2006); EMBASE (Excerpta Medica); Medline; and PsycINFO. The reference lists of relevant studies were checked, and ongoing research was sought through searches of Current Controlled Trials and the National Research Register.
What search terms/strategies were used?
Searches were carried out from inception to May 2006, and the strategy used in Medline is reproduced as an appendix.
What criteria were used to decide on which studies to include?
The inclusion criteria were deliberately broad, encompassing primary experimental and quasi-experimental studies with control groups that delivered CBT interventions to clinically stable outpatients aged 18 or older who were suffering from mild to moderate COPD. Only English language studies were selected. Further details of the inclusion criteria are given in the text.
Who decided on their relevance and quality?
The second author checked the 171 references delivered by the searches, eliminating 78 duplicates and 62 studies that did not meet the inclusion criteria on the basis of title and abstract. The remainder were retrieved in full text for further checking. The filtering process is summarised in a flow diagram.
Quality assessment of the selected trials was carried out by both authors using a modified version of the checklist developed by Guyatt (1994) and, where necessary, additional referenced criteria for assessing the quality of cohort studies.
How many studies were included and where were they from?
Four studies (three RCTs and one non-randomised trial) were included and are summarised in Table 1. Three were conducted in the USA and one in Brazil.
How were the study findings combined?
A modified version of a standardised data extraction form was used to record data on setting, study design, participants, baseline characteristics, intervention type, and outcomes (both physical and psychological). Differences between the studies and the outcome measures used precluded a meta-analysis. However, where possible, effect sizes were calculated by subtracting mean change scores for anxiety or depression in the control group from those in the experimental group, and dividing the sum by the pooled estimate of the standard deviation.
Findings of the review
The four trials compared the following: 1) CBT, exercise and education vs. CBT and education, as well as vs. a waiting list control group; 2) CBT vs. education; 3) CBT, exercise and education vs. exercise and education; and 4) CBT vs. standard care. All trial participants were older people, with the mean age of intervention groups ranging from 62.1 to 73 years; all participants were diagnosed as suffering from severe COPD (i.e. not the mild to moderate COPD that is the subject of the review); and all interventions were group-based and delivered by a single therapist.
All four trials investigated the effect of CBT on anxiety levels but used different outcome measures. Although the direction of the treatment effect ‘mainly favoured interventions that included CBT’, only one trial involving 30 patients produced a large and significant positive effect size. This showed that weekly sessions of CBT for 12 weeks, delivered as part of a pulmonary rehabilitation programme, can significantly reduce anxiety in COPD patients compared with standard care.
The three RCTs investigated the effect of CBT on depression, and again the direction of treatment effect was in favour of CBT interventions. The small trial that produced positive effects for anxiety also did so for depression, while a larger trial involving 79 patients produced significant reductions in depression for patients who received exercise training that included education and stress management classes based on a CBT format.
‘This systematic review shows that there is scant evidence of the effectiveness of CBT for reducing anxiety and/or depression in older adults with clinically stable severe COPD.’
Various methodological factors might explain ‘the equivocal and largely negative findings of the studies’, including small sample sizes, selection bias and the difficulty of isolating the treatment effects of CBT, especially when used with exercise and education.
It is also possible that the content and format of the CBT interventions may have been inappropriate for the participants. In some cases participants may have limited abilities to comprehend and use the coping skills acquired during CBT. Others may have found the group-based format insufficiently geared to their individual needs and wants.
Implications for policy or practice
Although there is clearly a need for further and better designed trials of the use of CBT with COPD patients, there may be scope to improve outcomes ‘by making psychotherapeutic interventions, especially CBT, more widely available as part of community-based pulmonary rehabilitation programmes.’
- Subject terms:
- long term conditions, anxiety, behaviour therapy, cognitive behavioural therapy, depression;
- Content type:
- systematic review
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