MATES in manufacturing: a cluster RCT evaluation of a workplace suicide prevention program

Background: The MATES in Construction suicide prevention program was adapted to the manufacturing sector and evaluated in a pilot of the program.Methods: Ten manufacturing worksites were randomly assigned to intervention (5 sites) and wait-list control (5 sites) conditions in a two-arm cluster randomized design. 1245 workers responded at baseline (87% response rate) and 648 at final (35% response rate). Literacy of Suicide Scale (LOSS) was assessed as a process outcome, and help-seeking intentions as the primary outcome (General Help-Seeking Questionnaire [GHSQ] score). Secondary outcomes included help sought, suicidal thoughts and likelihood of suicide attempt scores, and Kessler-6 scores. Linear mixed models for repeated measures were used in intention-to-treat (ITT) and completer analyses.Results: All sites finished the trial, with intervention periods ranging from 8 to 11 months; however, none of the five intervention sites fully implemented the intervention as planned. ITT analyses showed an improvement in LOSS scores within the intervention group (0.49, 95% CI 0.13-0.49), but the mean difference in change between intervention and control included the null (0.34, 95% CI −0.10 to 0.80). The primary outcome of GHSQ scores also improved within the intervention group, but the difference in change included the null (mean difference 1.52, 95% CI −0.69 to 3.74). No secondary outcomes improved relative to control in ITT or completers analyses. Exploratory analysis of disaggregated GHSQ help sources showed greater improvement in mean difference in change for the main MATES message of seeking help from MATES Connectors.Conclusion: The intervention, as implemented, was not effective at achieving the primary or secondary outcomes.Trial Registration: Australian and New Zealand Clinical Trial Registry: ACTRN 12622000122752.