Intended for healthcare professionals


Risk of suicide and related adverse outcomes after exposure to a suicide prevention programme in the US Air Force: cohort study

BMJ 2003; 327 doi: (Published 11 December 2003) Cite this as: BMJ 2003;327:1376
  1. Kerry L Knox, assistant professor of community and preventive medicine (Kerry_knox{at},
  2. David A Litts, special adviser to US surgeon general for suicide prevention2,
  3. G Wayne Talcott, chief of community prevention division3,
  4. Jill Catalano Feig, preventive medicine consultant4,
  5. Eric D Caine, John Romano professor of psychiatry1
  1. 1University of Rochester Center for the Study and Prevention of Suicide, University of Rochester Medical Center, Rochester, NY 14642, USA
  2. 2Department of Health and Human Services, Washington, DC 20007, USA
  3. 3Air Force Medical Operations Agency, Office of the Surgeon General, Brooks Air Force Base, San Antonio, TX 78235, USA
  4. 4Air Force Institute for the Environment, Safety and Occupation Health Risk Analysis, Brooks Air Force Base, San Antonio
  1. Correspondence to: K L Knox
  • Accepted 10 October 2003


Objective To evaluate the impact of the US Air Force suicide prevention programme on risk of suicide and other outcomes that share underlying risk factors.

Design Cohort study with quasi-experimental design and analysis of cohorts before (1990-6) and after (1997-2002) the intervention.

Participants 5 260 292 US Air Force personnel (around 84% were men).

Intervention A multilayered intervention targeted at reducing risk factors and enhancing factors considered protective. The intervention consisted of removing the stigma of seeking help for a mental health or psychosocial problem, enhancing understanding of mental health, and changing policies and social norms.

Main outcome measures Relative risk reductions (the prevented fraction) for suicide and other outcomes hypothesised to be sensitive to broadly based community prevention efforts, (family violence, accidental death, homicide). Additional outcomes not exclusively associated with suicide were included because of the comprehensiveness of the programme.

Results Implementation of the programme was associated with a sustained decline in the rate of suicide and other adverse outcomes. A 33% relative risk reduction was observed for suicide after the intervention; reductions for other outcomes ranged from 18-54%.

Conclusion A systemic intervention aimed at changing social norms about seeking help and incorporating training in suicide prevention has a considerable impact on promotion of mental health. The impact on adverse outcomes in addition to suicide strengthens the conclusion that the programme was responsible for these reductions in risk.


  • Contributors KLK, DAL, and EDC initiated the study and together with GWT and JCF designed the original protocol and coordinated the study. KLK analysed the data. All the authors contributed to the revision of the protocol and the writing of the paper, which was initially drafted by KLK and DAL. KLK is guarantor for the study.

  • Funding Department of Defense/Army/AMRDC, DAMD17-01-1-0797, R13 MH62073 (EDC), K24 MH01759 (Y Conwell), and K01 MH066317-01 (KLK).

  • Competing interests None declared

  • Ethical approval Institutional Review Boards at the University of Rochester, the US Air Force, and the US Department of Defense

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