This review aims to assess the cost-effectiveness of psychological interventions for schizophrenia/bipolar disorder (BD), to determine the robustness of current evidence and identify gaps in the available evidence.
Electronic searches (PsycINFO, MEDLINE, Embase) identified economic evaluations relating incremental cost to outcomes in the form of an Incremental Cost-Effectiveness Ratio (ICER) published in English since 2000. Searches were concluded in November 2018. Inclusion criteria were: adults with schizophrenia/BD; any psychological/psychosocial intervention (e.g. psychological therapy and integrated/collaborative care); probability of cost-effectiveness at explicitly-defined thresholds reported. Comparators could be routine practice, no intervention, or alternative psychological therapies. Screening, data extraction, and critical appraisal were performed using pre-specified criteria and forms. Results were summarised qualitatively. The protocol was registered on the PROSPERO database (CRD42017056579).
Of 3,864 studies identified, 12 met the criteria for data extraction. All were integrated clinical and economic randomised controlled trials. The most common intervention was cognitive behavioural therapy (CBT, 6/12 studies). The most common measure of health benefit was the quality-adjusted life-year (QALY) (6/12). Followup ranged from 6-months to 5-years. Interventions were found to be cost-effective in most studies (9/12): the probability of cost-effectiveness ranged from 35-99.5%. All studies had limitations and demonstrated uncertainty (particularly related to incremental costs).
Most studies concluded psychological interventions for schizophrenia/BD are cost-effective, including CBT, though there was notable uncertainty. Heterogeneity across studies makes it difficult to reach strong conclusions. There is a particular need for more evidence in the population with BD and for longer-term evidence across both populations.