Cost-effectiveness of structured group psychoeducation versus unstructured group support for bipolar disorder: Results from a multi-centre pragmatic randomised controlled trial

Highlights

• The cost-effectiveness of group psychoeducation (PEd) to treat BD is unknown.

• Data were collected as part of a pragmatic randomised controlled trial (RCT).

• The control treatment in the RCT was group peer support (PS).

• PEd may be cost-effective but this is uncertain.

• Further economic data may help to address this uncertainty.

Abstract

Background

Bipolar disorder (BD) costs the English economy an estimated £5.2billion/year, largely through incomplete recovery. This analysis estimated the cost-effectiveness of group psychoeducation (PEd), versus group peer support (PS), for treating BD.

Methods

A 96-week pragmatic randomised controlled trial (RCT), conducted in NHS primary care. The primary analysis compared PEd with PS, using multiple imputed datasets for missing values. An economic model was used to compare PEd with treatment as usual (TAU). The perspective was Health and Personal Social Services.

Results

Participants receiving PEd (n=153) used more (costly) health-related resources than PS (n=151) (net cost per person £1098 (95% CI, £252-£1943)), with a quality-adjusted life year (QALY) gain of 0.023 (95% CI, 0.001-0.056). The cost per QALY gained was £47,739. PEd may be cost-effective (versus PS) if decision makers are willing to pay at least £37,500 per QALY gained. PEd costs £10,765 more than PS to avoid one relapse. The economic model indicates that PEd may be cost-effective versus TAU if it reduces the probability of relapse (by 15%) or reduces the probability of and increases time to relapse (by 10%).

Limitations

Participants were generally inconsistent in attending treatment sessions and low numbers had complete cost/QALY data. Factors contributing to pervasive uncertainty of the results are discussed.

Conclusions

This is the first economic evaluation of PEd versus PS in a pragmatic trial. PEd is associated with a modest improvement in health status and higher costs than PS. There is a high level of uncertainty in the data and results.

Introduction

Bipolar disorder (BD) is the 18th leading cause of disability (years lived with) for any health problem (Vos et al., 2013). BD has been estimated to cost the English economy £5.2 billion annually, largely due to incomplete recovery as a result of inadequate treatment (McCrone et al., 2008).

Traditionally, medications such as lithium carbonate have been used to prevent episodes of illness and are still recommended for this purpose (National Collaborating Centre for Mental Health and National Institute for Clinical Excellence, 2014) but are only partially effective. In high income countries people with BD often have the opportunity to access peer support (PS) groups, in addition to medication and support from health professionals. People with BD value such support (Morselli et al., 2004) which may improve self-efficacy and be effective in managing many long term health conditions (Kennedy et al., 2007). Clinical guidelines for the management of BD recommend psychological treatment for the prevention of relapse in addition to pharmacotherapy (National Collaborating Centre for Mental Health and National Institute for Clinical Excellence, 2006, Veterans Administration and Department of Defense, 2010). Current guidelines for England recommend manualised evidence-based psychological interventions developed specifically for BD as a component of long-term management of BD (National Collaborating Centre for Mental Health and National Institute for Clinical Excellence, 2014).

Because relatively large groups 10–18 people) can undertake treatment together, manualised psychological interventions delivered to groups, for example group psychoeducation (PEd), may be an efficient option for mental health services to improve outcomes for people with BD. Although therapists need to be trained to run the groups, the intervention is highly manualised and training is less intensive than for other psychological approaches such as individual cognitive behavioural therapy (CBT) (Colom and Vieta, 2006). The existing evidence base for group psychological treatments in preventing relapses for BD is inconsistent. The first trial of PEd in a group of people with BD, showed clinical and cost-effectiveness for all types of bipolar relapse (Colom et al., 2009, Colom et al., 2003a, Colom et al., 2003b). Generally however findings from previous trials of PEd have been heterogeneous in design, often involving a small number of participants and short follow-up periods. They reported inconsistent effects on mood symptoms, quality of life, or functioning (Bond and Anderson, 2015).

The analyses described here were part of an integrated clinical and economic randomised controlled trial (RCT) of the effectiveness of PEd compared to PS (trial acronym: PARADES) (Dunn and Makin, 2015). Results suggested that while PEd was no more clinically effective than PS it was more acceptable to participants. PS, rather than treatment as usual (TAU), was chosen as the comparator in the RCT as the clinical aim was to compare PEd with an unstructured group-based intervention, matching for attentional effects. However, PS is not standard care in the UK, opportunities to access PS are highly variable, and to our knowledge there is no plan to establish PS in clinical practice. Furthermore a key problem identified in the National Institute for Health and Care Excellence (NICE) guideline for bipolar disorder (CG185) was that there was insufficient evidence to model the relative cost-effectiveness of psychological therapies compared to TAU (National Collaborating Centre for Mental Health and National Institute for Clinical Excellence, 2014). This is important because the decision problem facing providers is whether or not to provide PEd in addition to TAU, rather than which intervention to provide between PEd and PS. In order to address this, a simple economic model and threshold analysis were used to synthesise results of the RCT with clinical literature. This approach provides additional information for settings or patient groups where access to psychological therapies such as that provided by PS is limited (Dunn and Makin, 2015).

The overall aim of the economic evaluation was to explore the likelihood that PEd is cost-effective. Specific objectives were to:

• Estimate and compare the costs and quality-adjusted life years (QALYs) for participants in the intervention (PEd) and control (PS) groups at baseline and follow-up;

• Use RCT data to assess whether there were differences in the relative cost-effectiveness of PEd compared with PS;

• As PS is unlikely to be adopted as routine practice, explore whether PEd could be cost-effective compared with TAU, using a probabilistic simulation (economic) model.