Prediction of Suicide and Nonfatal Self-harm After Bariatric Surgery: A Risk Score Based on Sociodemographic Factors, Lifestyle Behavior, and Mental Health: A Nonrandomized Controlled Trial.

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.