Gatekeeper training for suicide prevention: a systematic review and meta-analysis of randomized controlled trials

Gatekeeper training (GKT) aims to enhance suicide gatekeepers' (GKs) abilities in assessing suicide risk, identify those at-risk and refer them. However, existing randomized controlled trials (RCTs) on GKT have not produced definitive results. This study reviewed RCTs on GKT to provide evidence for developing effective suicide prevention strategies.

We conducted a systematic search of MEDLINE, PubMed, Web of Science, PsycINFO, CINAHL, Embase, Google Scholar, Medrxiv, and Ebsco for English-language RCTs published between January 1, 2000, and December 31, 2024. Two authors independently screened studies, extracted data, and assessed the risk of bias using the Cochrane risk-of-bias tool. Standardized mean differences (SMD) with 95% confidence intervals were calculated using a random-effect model. Heterogeneity was assessed by using I² statistic, and publication bias was evaluated through funnel plots and Egger's regression. We stratified participants into subgroups by characteristics and categorized interventions by delivery mode (online vs. offline). Post-test and follow-up data were integrated into a unified model, with follow-ups classified as short-term (1-5 months) or long-term (> 5 months). All analyses were performed using R version 3.4.0, following the PRISMA guidelines (registration number: CRD42024507513).

Sixteen studies were included. Compared to the control group, gatekeepers showed increased suicide knowledge (SMD = 0.72, 95% CI: 0.32 - 1.13) and enhanced self-efficacy (SMD = 0.73, 95% CI: 0.33 - 1.13) for suicide prevention. For knowledge, the improvements were sustained in the short-term (SMD = 0.64, 95% CI: 0.22 - 1.06) but diminished in the long-term (SMD = 0.25, 95% CI: 0.05 - 0.45). Online interventions showed a significant improvement in self-efficacy (SMD = 1.02, 95% CI: 0.73 - 1.32), while offline interventions demonstrated a potential but non-significant improvement (SMD = 0.53, 95% CI: -0.08 - 1.17). Preparedness also showed a significant improvement (SMD = 0.69, 95% CI: 0.31 - 1.07).

This meta-analysis demonstrated GKT's effectiveness in enhancing knowledge and self-efficacy (moderate effect) for suicide prevention. However, the positive effects tend to decrease over time. Online training offers significant benefits, making it a viable option for widespread implementation. Additionally, the selection of gatekeepers plays a crucial role in ensuring the effectiveness of online GKT programs.