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

Abstract

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.

Figure 1.. Cost-effectiveness Plane for 24-Month Results for the Number of Suicide Attempts

The majority of bootstrapped paired dots representing differences in pairs of costs and effects were scattered across the southwest quadrant. This indicates that the Attempted Suicide Short Intervention Program is highly likely to be less costly and more effective in reducing the number of reattempts, compared with the control group. The x-axis represents the incremental effect in terms of the number of suicide attempts. The lower the number, the better the effect.

Figure 2.. Cost-effectiveness Acceptability Curve

The graph shows the probability of the Attempted Suicide Short Intervention Program being cost-effective at different willingness-to-pay levels.