Method choice in nonfatal self-harm as a predictor of subsequent episodes of self-harm and suicide: Implications for clinical practice

Objectives. We examined time-varying and time-invariant characteristics of nonfatal intentional self-harm episodes in relation to subsequent episodes of self-harm and suicide. Methods. We conducted a follow-up cohort study through 2007 of 3600 patients discharged from hospitals in New Jersey with a primary diagnosis of intentional self-harm in 2003. We determined repetition of self-harm from hospital records and suicide from state registers. Results. Use of methods other than drug overdose and cutting in self-harm events, greater medical severity of nonfatal episodes, and a history of multiple self-harm episodes increased the risk of suicide. However, most suicides occurred without these risk factors. Most suicides took place without intervening episodes of self-harm, and most persons used a low-lethality method (drug overdose or cutting) in their index episode, but switched to a more lethal method in their fatal episode. Conclusions. Our findings suggest that preventing suicide among persons with a history of self-harm must account for the possibility that they will adopt methods with higher case-fatality ratios than they previously tried.