Cost-effectiveness of an extended-role general practitioner clinic for persistent physical symptoms: results from the Multiple Symptoms Study 3 (MSS3) pragmatic randomised controlled trial

Abstract

To evaluate the cost-effectiveness of an extended-role general practitioner (GP) symptoms clinic (SC), added to usual care (UC) for patients with multiple persistent physical symptoms (sometimes known as "medically unexplained symptoms"). A 52-week within-trial cost-utility analysis of a pragmatic multicentre randomised controlled trial comparing SC+UC (n=178) against UC alone (n=176), conducted from the primary perspective of the UK National Health Service (NHS) and personal and social services (PSS). Base-case quality-adjusted life-years (QALYs) were measured using EQ-5D-5L. Missing data were imputed using multiple imputation (MI). Cost-effectiveness results were presented as incremental cost-effectiveness ratios (ICERs) and incremental net monetary benefits (INMBs). Uncertainty was explored using cost-effectiveness acceptability curves (using 1000 non-parametric bootstrapped samples) and sensitivity analysis (including societal costs, using SF-6D and capability ICECAP-A outcomes to estimate QALYs and years of full capability (YFC) respectively, varying intervention costs, missing data mechanism assumptions). Multiple imputation analysis showed that, compared to UC alone, SC+UC was more expensive [(adjusted mean cost difference: 704; 95% CI:£605, £807)] and more effective [(adjusted mean QALY difference: 0.0447 (95% CI:0.0067, 0.0826)] yielding an ICER of £15,765/QALY, INMB of £189.22 (95% CI:-£573.62, £948.28) and a 69% probability of the SC+UC intervention arm being cost-effective at a threshold of £20000 per QALY. Results were robust to most sensitivity analyses, but sensitive to missing data assumptions (2 of the 8 scenarios investigated), SF-6D and ICECAP-A quality of life outcomes. A Symptoms Clinic is likely to be a potentially cost-effective treatment for patients with persistent physical symptoms.