The Prevalence of Nonsuicidal Self-Injury in Military Personnel: A Systematic Review and Meta-Analysis.

Military service members and veterans (SMVs) are at risk for self-directed violence, including nonsuicidal self-injury (NSSI). While NSSI is an important construct worthy of independent study, it is understudied among SMVs and, when included in research, typically examined in the context of suicide risk. Consequently, lifetime prevalence rate estimates of NSSI among SMVs vary. This Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review and meta-analysis estimated the average lifetime NSSI prevalence among SMVs and explored demographic and methodological factors that may account for observed variability. Based on a search of Ovid MEDLINE, Embase, PsycINFO, and Web of Science, 47 samples from 42 articles across five countries met inclusion criteria. Results revealed an average NSSI lifetime prevalence rate of 15.76% among SMVs. Significantly higher prevalence rates were observed among clinical (28.14%) versus community (11.28%) samples and studies using interviews to assess NSSI (23.56%) versus self-report (13.44%) or chart review (7.84%). Lifetime prevalence increased as publication year increased and decreased as sample size increased. In contrast to prior literature, prevalence rates were comparable between active-duty SMVs, and studies collecting data anonymously versus those that did not. Lifetime prevalence was not moderated by age, gender, race, country, primary research focus, quality of NSSI operationalization, or whether NSSI methods were assessed. Findings suggest NSSI is a pervasive problem among military personnel, particularly within clinical settings, highlighting the need for systematic assessment of this important but understudied clinical phenomenon among SMVs. Further research is necessary to elucidate additional risk factors for NSSI among SMVs, including trauma exposure.