QUESTION, PERSUADE, REFER (QPR) IS EFFECTIVE AND EVIDENCE-BASED.
The recognition of suicide as an imminent concern has led to the development of evidence-based prevention programs to decrease suicide-related mortality. One program, Question, Persuade, Refer (QPR), has become the most widely-distributed gatekeeper training program in the world. Research indicates both short- and long-term positive outcomes in knowledge and self-efficacy, supporting use of QPR. Independent research reviewers of published studies for National Registry of Evidence-based Practice and Policies found that trained gatekeepers have increased knowledge, confidence and gatekeeper skills per these measures:

Declarative & perceived knowledge
Self-efficacy
Diffusion of Gatekeeper training information
Gatekeeper skills (ability to engage in active listening, ask clarifying questions,
make an appropriate referral)

References: https://qprinstitute.com/research-theory
Cross, W.F., Seaburn, D., Gibbs, D., Schmeelk-Cone, K. et al. (2011);Matthieu, M.M., Cross, W., Batres. A.R., Flora et al.
(2008);Wyman, P.A., Brown, C.H. Inman, J., Cross W., et al (2008).
Definition: According to the Surgeon General’s National Strategy for Suicide Prevention (2001), “key gatekeepers” are
“people who regularly come into contact with individuals or families in distress”
Reference: Litteken, Clay & Sale, Elizabeth. (2018). Long-Term Effectiveness of the Question, Persuade, Refer (QPR)
Suicide Prevention Gatekeeper Training Program: Lessons from Missouri. Community Mental Health Journal. 54. 1-11.
10.1007/s10597-017-0158-z.