Assessment of Latent Subgroups with Suicidal Ideation and Suicidal Behavior among Gun Owners and Non-Gun Owners in the US

IMPORTANCE Firearm ownership is associated with increased risk for suicide. OBJECTIVE To examine patterns of associations among suicidal thoughts and behaviors among gun owners and non-gun owners in the US. DESIGN, SETTING, AND PARTICIPANTS In this survey study, cross-sectional online survey data were collected from March to April 2020 from US adults recruited via Qualtrics Panels. Quota sampling was used to approximate US census demographics. MAIN OUTCOMES AND MEASURES The primary outcomes were past-year passive suicidal ideation, active suicidal ideation, suicidal planning, suicidal behaviors, and nonsuicidal self-injury as measured by items from the Self-Injurious Thoughts and Behaviors Interview-Revised (SITBI-R). Simple latent class analysis (LCA) was used to assign participants to separate classes based on posterior probabilities, and multigroup LCA was used to assess whether the same construct was measured in specified groups. RESULTS Of 65 079 adults invited to participate, 10 625 (16.3%) completed the survey; 9153 responded "yes" or "no" to the firearm ownership item and were included in the analysis. Of these 9153 respondents (4695 [51.3%] male; mean [SD] age, 46.7 [16.8] years), 2773 (30.3%) reported owning a gun and 6380 (69.7%) reported not owning a gun. Compared with non-gun owners, gun owners were more likely to be male (1779 [64.2%] vs 2916 [45.7%]; chi(2)(1) 263.3; P < .001) and White (2090 [75.4%] vs 3945 [61.8%]; chi(2)(5) 232.9; P < .001) and to have served in the military (772 [27.8%] vs 609 [9.5%]; chi(2)(1) 571.4; P < .001). Five distinct patterns of SITBI-R item endorsement were extracted using simple LCA. Multigroup LCA indicated that the probability of SITBI-R item endorsement differed between gun owners and non-gun owners across subgroups. Among gun owners, the probability of past-month nonfatal suicide attempts was highest in class 4 (ranging from 16.8% for reaching out for help to 27.2% for starting, then changing one's mind). Gun owners in class 4 were characterized by high probabilities of endorsing thoughts about specific ways or methods to attempt suicide (100%) and preparatory behavior (100%). Among non-gun owners, the probability of nonfatal suicide attempts was highest in class 5 (ranging from 14.9% for reaching out for help to 29.7% for starting, then changing one's mind). Non-gun owners in class 5 were characterized by high probabilities of endorsing passive suicidal ideation (84.0%-100%), active suicidal ideation (86.7%-95.0%), and thoughts about specific ways or methods to attempt suicide (97.4%) and a specific place (92.1%) to attempt suicide. CONCLUSIONS AND RELEVANCE In this study, in subgroups with lower probabilities of suicide attempt, gun owners and non-gun owners showed similar patterns of suicide risk item endorsement, but when the probability of a suicide attempt increased, gun owners were less likely than non-gun owners to endorse passive and active suicidal ideation. These findings suggest that assessing a broader range of suicide risk indicators may improve risk detection.