Abstract
OBJECTIVE: To identify preoperative sociodemographic and health-related factors that predict higher risk of nonfatal self-harm and suicide after bariatric surgery. BACKGROUND: Evidence is emerging that bariatric surgery is related to an increased risk of suicide and self-harm, but knowledge on whether certain preoperative characteristics further enhance the excess risk is scarce. METHODS: The nonrandomized, prospective, controlled Swedish Obese Subjects study was linked to 2 Nationwide Swedish registers. The bariatric surgery group (N = 2007, per-protocol) underwent gastric bypass, banding or vertical banded gastroplasty, and matched controls (N = 2040) received usual care. Participants were recruited from 1987 to 2001, and information on the outcome (a death by suicide or nonfatal self-harm event) was retrieved until the end of 2016. Subhazard ratios (sub-HR) were calculated using competing risk regression analysis. RESULTS: The risk for self-harm/suicide was almost twice as high in surgical patients compared to control patients both before and after adjusting for various baseline factors [adjusted sub-HR = 1.98, 95% confidence interval (CI) = 1.34-2.93]. Male sex, previous healthcare visits for self-harm or mental disorders, psychiatric drug use, and sleep difficulties predicted higher risk of self-harm/suicide in the multivariate models conducted in the surgery group. Interaction tests further indicated that the excess risk for self-harm/suicide related to bariatric surgery was stronger in men (sub-HR = 3.31, 95% CI = 1.73-6.31) than in women (sub-HR = 1.54, 95% CI = 1.02-2.32) (P = 0.007 for adjusted interaction). A simple-to-use score was developed to identify those at highest risk of these events in the surgery group. CONCLUSIONS: Our findings suggest that male sex, psychiatric disorder history, and sleep difficulties are important predictors for nonfatal self-harm and suicide in postbariatric patients. High-risk patients who undergo surgery might require regular postoperative psychosocial monitoring to reduce the risk for future self-harm behaviors.