Group cognitive behavioural therapy for postnatal depression : a systematic review of clinical effectiveness, cost effectiveness and value of information analyses

Background: Postnatal depression (PND) describes a wide range of distressing symptoms that can occur in women following childbirth. There is substantial evidence to support the use of cognitive behaviour therapy (CBT) in the treatment of depression, and psychological therapies are recommended by the National Institute for Health and Clinical Excellence as a first-line treatment for PND. However, access is limited owing to expense, waiting lists and availability of therapists. Group CBT may, therefore, offer a solution to these problems by reducing therapist time and increasing the number of available places for treatment. Objectives: To evaluate the clinical effectiveness and cost-effectiveness of group CBT compared with currently used packages of care for women with PND. Data sources: Seventeen electronic bibliographic databases were searched (for example MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, PsycINFO, etc.), covering biomedical, health-related, science, social science and grey literature (including current research). Databases were searched from 1950 to January 2008. In addition, the reference lists of relevant articles were checked and various health services’ related resources were consulted via the internet. Review methods: The study population included women in the postpartum period (up to 1 year), meeting the criteria of a standardised PND diagnosis using the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition, or scoring above cut-off on the Edinburgh Postnatal Depression Scale (EPDS). No exclusion was made on the basis of the standardised depression screening/case finding instrument of standardised clinical assessment tool used to define PND. All full papers were read by two reviewers (AS and DS) who made independent decisions regarding inclusion or exclusion, and consensus, where possible, was obtained by meeting to compare decisions. In the event of disagreement, a third reviewer (EK) read the paper and made the decision. All data from included quantitative studies were extracted by one reviewer (AS) using a standardised data extraction form. All data from included qualitative studies were extracted by two reviewers (AS and AB) using a standardised data extraction form with disagreements resolved by discussion. Two different data extraction forms were used, one for the quantitative papers and a second for the qualitative papers. Results: Six studies met the inclusion criteria for the quantitative review. Three were randomised controlled trials (RCTs) and three were non-randomised trials. Two studies met the inclusion criteria for the qualitative review. These were both treatment evaluations incorporating qualitative methods. Only one study was deemed appropriate for the decision problem; therefore a meta-analysis was not performed. This study indicated that the reduction in the EPDS score through group CBT compared with routine primary care (RPC) was 3.48 [95% confidence interval (CI) 0.23 to 6.73] at the end of the treatment period. At 6-month follow-up the relative reduction in EPDS score was 4.48 (95% CI 1.01 to 7.95). Three studies showed the treatment to be effective in reducing depression when compared to RPC, usual care or waiting list groups. There was no adequate evidence on which to assess group CBT compared with other treatments for PND. Two studies of group CBT for PND were included in the qualitative review. Both studies demonstrated patient acceptability of group CBT for PND, although negative feelings towards group CBT were also identified. A de novo economic model was constructed to assess the cost-effectiveness of group CBT. The base-case results indicated a cost per quality-adjusted life-year (QALY) of £46,462 for group CBT compared with RPC. The 95% CI for this ratio ranged from £37,008 to £60,728. There was considerable uncertainty in the cost per woman of running a CBT course, of the appropriateness of efficacy data to the decision problem, and the residual length of benefit associated with group CBT. These were tested using univariate sensitivity analyses. Supplementary analyses that fitted distributions to the cost of treatment and the duration of comparative advantage reported a cost per QALY of £36,062 (95% CI £20,464 to £59,262). Limitations The cost per QALY ratio for group CBT in PND was uncertain because of gaps in the evidence base. There was little quantitative or qualitative RCT evidence to assess the effectiveness of group CBT for PND. The evidence that was available was of low quality in the main because of poor reporting of the results. Furthermore, little information was reported on concurrent treatment used in the studies, which was controlled for in only two of the studies. Conclusions: Evidence from the clinical effectiveness review provided inconsistent and low quality information on which to base any interpretations for service provision. Although three of the included studies provided some indication that group psycho-education incorporating CBT is effective compared with RPC, there is enough doubt in the quality of the study, the level of CBT implemented in the group programmes, and the applicability to a PND population to limit any interpretations significantly. It is also considered that the place of group CBT in a stepped care programme needs to be identified, as well as there being a need for a clearer referral process for group CBT