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.