Cost-effectiveness of brief structured interventions to discontinue long-term benzodiazepine use: an economic analysis alongside a randomised controlled trial.

Background: In Spain, long-term use of benzodiazepine is prevalent in 7% of the population; however, this longer-term use lacks clinical benefits, costs €90million per year and side-effects further add extra cost through adverse health outcomes. This study aims to estimate the cost-effectiveness of primary care services stepped dose reduction of long-term benzodiazepines using either Structured Interview with Follow-up (SIF) or Without Follow-up (SIW), compared to Treatment as Usual (TAU). Design: Cost-effectiveness analysis was conducted alongside randomised control utilizing data from three arm cluster randomized trial. Setting: Primary care. Participants: 75 general practitioners were randomised to one of the three arms (TAU, SIW, SIF). Measurements: Cost and Cost per Quality-Adjusted Life Year (QALY) Results: Compared to usual care, providing SIW per participant costs an additional €117.94 and adding patient follow-up, €218.4. As a result of intervention, participants showed a gain of, on average, for SIW 0.0144 QALY (95% CI -0.0137 to 0.0425) and for SIF 0.0340 QALYs (0.0069 to 0.0612). The Incremental Cost Effectiveness Ratio was €8190.28/QALY (SIW) and €6423.53/QALY (SIF). At the Spanish reimbursement threshold (€45,000 per QALY) the chance interventions are cost effective is 79.8% for SIW and 97.7% for SIF. Conclusions: Brief structured interventions to discontinue long-term benzodiazepine use represent value for money, particularly with scheduled follow-up appointments, and would represent a cost-effective investment by the Spanish healthcare to reduce prevalence of long-term use.