Cost-Utility Analysis of Discontinuing Antidepressants in England Primary Care Patients Compared with Long-Term Maintenance: The ANTLER Study

Background Depression is a common mental health condition with considerable negative impact on health and well-being. Although antidepressants are recommended as first-line treatment, there is limited evidence regarding the cost effectiveness of long-term maintenance antidepressants for preventing relapse. Objectives Our objective was to calculate the mean incremental costs and quality-adjusted life-years (QALYs) over 12 months of discontinuing long-term antidepressant medication in well patients compared with maintenance, using patient-level trial data. Methods We conducted a cost-utility analysis of 478 participants from 150 UK general practices recruited to a randomised, double-blind trial (ANTLER). QALYs were calculated from EQ-5D-5L and 12-Item Short Form survey (SF-12) results, with primary analysis using the EQ-5D-5L value set for England. Resource use was collected from primary care patient electronic medical records and self-completed questionnaires capturing mental-health-related resource use. Costs were calculated by applying standard UK unit costs to resource use. Adjustments were made for baseline variables. Results Participants randomised to discontinuation had significantly worse utility scores at 3 months (− 0.032; 95% confidence interval [CI] − 0.053 to − 0.011) but no significant difference in QALYs (− 0.011; 95% CI − 0.026 to 0.003) or costs (£3.11; 95% CI − 41.28 to 47.50) at 12 months. The probability that discontinuation was cost effective compared with maintenance was 12.9% at a threshold of £20,000 per QALY gained. Conclusions Discontinuation of antidepressants was unlikely to be cost effective compared with maintenance for currently well patients on long-term antidepressants. However, this analysis provides no information on the wider impact of antidepressants. Our findings provide information on the potential impact of discontinuing long-term maintenance antidepressants and facilitate improving guidance for shared patient–clinician decision making. Trial Registration EudraCT number 2015-004210-26; ISRCTN number ISRCTN15969819.