Self-harm emergencies after bariatric surgery: a population-based cohort study

Importance — Self-harm behaviors including suicidal ideation and past attempts are frequent in bariatric surgery candidates. It is unclear, however, whether these behaviors are mitigated or aggravated by surgery.

Objective — To compare the risk of self-harm behaviors before and after bariatric surgery.

Design — Population-based self-matched longitudinal-cohort analysis.

Setting — Ontario, Canada.

Participants — Adults operated between April 1, 2006 and March 31, 2011 in Ontario.

Intervention — Bariatric surgery.

Outcome — Self-harm emergencies three years before and after surgery.

Results — The cohort included 8,815 patients of whom most were women (81%), 35 years or older (80%), and treated with gastric bypass (98%). A total of 111 patients had 158 self-harm emergencies during follow-up. Overall, self-harm emergencies significantly increased after surgery (3.63/1,000 patient-years) compared to before surgery period (2.33/1,000 patient-years), equaling an incidence rate ratio (RR) of 1.54 (95% confidence interval [95% CI]=1.03-2.30; P=0.007). Self-harm emergencies after surgery were especially higher than before surgery among patients older than 35 years (RR=1.76; 95% CI=1.05-2.94), those with a low-income status (RR=2.09, 95%CI=1.20-3.65), and those living in rural areas (RR=6.49; 95% CI=1.42-29.63). The most common self-harm mechanism was an intentional overdose (73%). About 93% of events occurred in patients diagnosed with a depressive disorder during the five years prior to the surgery.

Conclusion and Relevance — The risk of self-harm emergencies increased after bariatric surgery, underscoring the need of suicide risk screening during follow-up.