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

Stevenson MD, Scope A, Sutcliffe PA, et al.; the group cognitive behavioural therapy for postnatal depression advisory group.

Publication Details

Background

Postnatal depression (PND) describes a wide range of distressing symptoms that can occur in women following childbirth. A clinical diagnosis of the disorder is often made using the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition which describes a range of diagnostic categories indicative of a depressive disorder. 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

The overall aims of the review were to evaluate the clinical effectiveness and cost-effectiveness of group CBT compared with currently used packages of care for women with PND.

Methods

Clinical effectiveness

A systematic review of the literature was performed to identify all studies describing trials of group CBT for PND. Databases were searched (for example MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, PsycINFO, etc.) from 1950 to January 2008 for both quantitative and qualitative studies.

Cost-effectiveness

A systematic review of the literature was performed to identify all cost-effectiveness studies of group CBT for PND. Databases were searched from 1950 to January 2008.

Results

Number and quality of studies

Clinical effectiveness

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.

Cost-effectiveness

No studies were identified that were deemed relevant to the decision problem.

Evidence of effectiveness

Clinical effectiveness

Six studies of group CBT for PND were included in the quantitative review as part of a narrative analysis. 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 Edinburgh Postnatal Depression Scale (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.

Cost-effectiveness

A de novo economic model was constructed to assess the cost-effectiveness of group CBT.

Summary of cost-effectiveness

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).

Sensitivity analyses

The cost of running a group CBT course, the assumed efficacy of group CBT and the length of residual benefit all markedly affected the results; plausible combinations of these values would produce cost per QALY values below currently used thresholds. Expected value of information analyses were undertaken. These showed that there was expected to be a considerable benefit in conducting further research, particularly regarding the cost of treatment and the relationship between changes in values of the EPDS and changes in the value of the Short Form questionnaire-6 Dimensions (SF-6D).

Discussion

Strengths, limitations and uncertainties of the analyses

A strength of our work is that an estimation of the cost-effectiveness of group CBT for PND in the UK has been calculated; previously such estimates have not been published. Furthermore, a relationship between a change in EPDS score and utility has been estimated, although the correlation is only moderate. We believe that such a relationship has not previously been published. The analyses have shown that the cost per QALY is heavily dependent on the cost per women treated with group CBT and the assumed relationship between changes in EPDS values and changes in SF-6D values.

Limitations include the dearth of RCT evidence to assess the effectiveness of group CBT for PND. The available evidence was in some cases of low quality due to poor reporting. Some of the included studies failed to provide adequate information about the exact nature of the CBT element of the intervention, concurrent treatment in the intervention group, and patient characteristics such as time postpartum. These factors may have significant implications for the generalisability of the findings. Furthermore, the potentially small number of health visitors involved in delivering the group CBT assumed applicable to the UK setting may provide severe limitations in generalising the results to other health visitors.

No robust comparisons between group CBT and individual CBT, or between group CBT and other group therapies, were found. For the quantitative analyses only one RCT was considered appropriate for meta-analysis and this had only 45 participants. A further limitation is that utility measurements were not recorded in the RCTs, thus benefits were estimated from a regression of the relationship between EPDS and SF-6D.

As such there is considerable uncertainty in the estimated efficacy of group CBT compared with RPC. This, and uncertainties in the costs of conducting group CBT and in the duration of benefit, mean that the cost-effectiveness of group CBT for PND is uncertain.

Conclusions

Implications for service provision

Evidence from the clinical effectiveness review provides inconsistent and low quality information on which to base any interpretations for service provision. Although three of the included studies provide 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. There is also a requirement to make clearer assessments of the facilitators and resources required for group CBT, including training needs, and to provide a clear method of assessing suitable participants for the treatment.

Suggested research priorities

The key research priorities would be to determine the cost per woman of providing group CBT were it to be widely available, collection of paired data for EPDS and a utility measure such as the SF-6D, to determine the effectiveness of group CBT compared with RPC and individual CBT (preferably in terms of a utility measure to obviate the transformation from the EPDS) and to determine the duration of comparative advantage by following up the women 1 year, or longer, after randomisation.

If the sample size is large enough, data on the following aspects should be recorded: the effect of the size of the participant group; the effect of the session duration; the effect of the setting; the qualifications and involvement of the facilitator; the effectiveness of group CBT on the different subtypes of PND; whether effectiveness is dependent on patient background, comorbidity, the number of children, previous PND, pre-pregnancy or antenatal depression; and the indirect effects of the treatment on the infant and other family members.

Publication

  • Stevenson MD, Scope A, Sutcliffe PA, Booth A, Slade P, Parry G, et al. Group cognitive behavioural therapy for postnatal depression: a systematic review of clinical effectiveness, cost-effectiveness and value of information analyses. Health Technol Assess 2010;14(44). [PubMed: 20863477]

NIHR Health Technology Assessment programme

The Health Technology Assessment (HTA) programme, part of the National Institute for Health Research (NIHR), was set up in 1993. It produces high-quality research information on the effectiveness, costs and broader impact of health technologies for those who use, manage and provide care in the NHS. ‘Health technologies’ are broadly defined as all interventions used to promote health, prevent and treat disease, and improve rehabilitation and long-term care.

The research findings from the HTA programme directly influence decision-making bodies such as the National Institute for Health and Clinical Excellence (NICE) and the National Screening Committee (NSC). HTA findings also help to improve the quality of clinical practice in the NHS indirectly in that they form a key component of the ‘National Knowledge Service’.

The HTA programme is needs led in that it fills gaps in the evidence needed by the NHS. There are three routes to the start of projects.

First is the commissioned route. Suggestions for research are actively sought from people working in the NHS, from the public and consumer groups and from professional bodies such as royal colleges and NHS trusts. These suggestions are carefully prioritised by panels of independent experts (including NHS service users). The HTA programme then commissions the research by competitive tender.

Second, the HTA programme provides grants for clinical trials for researchers who identify research questions. These are assessed for importance to patients and the NHS, and scientific rigour.

Third, through its Technology Assessment Report (TAR) call-off contract, the HTA programme commissions bespoke reports, principally for NICE, but also for other policy-makers. TARs bring together evidence on the value of specific technologies.

Some HTA research projects, including TARs, may take only months, others need several years. They can cost from as little as £40,000 to over £1 million, and may involve synthesising existing evidence, undertaking a trial, or other research collecting new data to answer a research problem.

The final reports from HTA projects are peer reviewed by a number of independent expert referees before publication in the widely read journal series Health Technology Assessment.

Criteria for inclusion in the HTA journal series

Reports are published in the HTA journal series if (1) they have resulted from work for the HTA programme, and (2) they are of a sufficiently high scientific quality as assessed by the referees and editors.

Reviews in Health Technology Assessment are termed ‘systematic’ when the account of the search, appraisal and synthesis methods (to minimise biases and random errors) would, in theory, permit the replication of the review by others.

The research reported in this issue of the journal was commissioned by the HTA programme as project number 06/83/01. The contractual start date was in January 2008. The draft report began editorial review in June 2009 and was accepted for publication in January 2010. As the funder, by devising a commissioning brief, the HTA programme specified the research question and study design. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The HTA editors and publisher have tried to ensure the accuracy of the authors’ report and would like to thank the referees for their constructive comments on the draft document. However, they do not accept liability for damages or losses arising from material published in this report.

The views expressed in this publication are those of the authors and not necessarily those of the HTA programme or the Department of Health.

Editor-in-Chief: Professor Tom Walley CBE

Series Editors: Dr Martin Ashton-Key, Dr Aileen Clarke, Professor Chris Hyde, Dr Tom Marshall, Dr John Powell, Dr Rob Riemsma and Professor Ken Stein