Cost-effectiveness of a brief structured intervention program aimed at preventing repeat suicide attempts among those who previously attempted suicide: a secondary analysis of the ASSIP randomized clinical trial

IMPORTANCE: This is the first cost-effectiveness analysis of a brief therapy, the Attempted Suicide Short Intervention Program (ASSIP), for individuals who attempt suicide. OBJECTIVE: To explore the cost-effectiveness of the ASSIP intervention in the context of the Swiss health care system. DESIGN, SETTING, AND PARTICIPANTS: In this economic evaluation, the cost-effectiveness analysis was performed from a health care perspective between January 2017 and April 2018 using data from a randomized clinical trial conducted between June 2009 and December 2014. Participants were individuals who had attempted suicide and were receiving treatment at a psychiatric university hospital in Switzerland that provides inpatient and outpatient services for suicide attempters referred from an emergency department of a general hospital. INTERVENTIONS: The intervention group received 3 manual-based therapy sessions followed by regular personalized letters over 24 months. The control group was offered a single suicide risk assessment. MAIN OUTCOMES AND MEASURES: The main economic analysis explored cost per suicide attempt avoided expressed in 2015 Swiss francs (CHF). Cost-effectiveness planes were plotted and cost-effectiveness acceptability curves calculated. RESULTS: One hundred twenty participants (mean [SD] age, 37.8 [14.4] years; 66 [55%] women and 54 [45%] men) were assigned to an intervention group or a control group, each with 60 participants. At 24 months of follow-up, 5 suicide attempts were reported in the ASSIP group among 59 participants with follow-up data available, and 41 were reported in the control group among 53 participants with follow-up data available. The ASSIP group had higher intervention costs, with CHF 1323 vs CHF 441 for the control group. At 24 months of follow-up, psychiatric hospital costs were lower in the ASSIP group than in the control group, although this difference was not significant (mean [SD], CHF 20 559 [38 676] vs CHF 45 488 [73 306]; mean difference, CHF -16 081; 95% CI, CHF -34 717 to 1536; P = .11). General hospital costs were significantly lower for the ASSIP group. Total health care costs were also lower, but the difference was not significant (mean [SD], CHF 21 302 [38 819] vs 41 287 [74 310]; difference, CHF -12 604; 95% CI, CHF -29 837 to 625; P = .14). In a base-case analysis, ASSIP was dominant, with significantly fewer reattempts at lower overall cost. The intervention had a 96% chance of being less costly and more effective. A sensitivity analysis showed a 96% and 95% chance of ASSIP being more effective and less costly at willingness-to-pay levels of CHF 0 and CHF 30 000, respectively. CONCLUSIONS AND RELEVANCE: The ASSIP intervention is a cost-saving treatment for individuals who attempt suicide. The findings support the use of ASSIP as a treatment for suicide attempters. Further studies are needed to determine cost-effectiveness in other contexts. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02505373