Non-fatal repetition of self-harm in Taipei City, Taiwan: cohort study.

Background: Repeat self-harm is an important risk factor for suicide. Few studies have explored risk factors for non-fatal repeat self-harm in Asia.
Aims: To investigate the risk of non-fatal repeat self-harm in a large cohort of patients presenting to hospital in Taipei City, Taiwan.
Method: Prospective cohort study of 7601 patients with self-harm presenting to emergency departments (January 2004-December 2006). Survival analysis was used to examine the rates, timing and factors associated with repeat self-harm.
Results: In total 778 (10.2%) patients presented to hospital with one or more further episodes of self-harm. The cumulative risk of non-fatal repetition within 1 year of a self-harm episode was 9.3% (95% CI 8.7-10.1). The median time to repetition within 1 year was 105 days. Females had a higher incidence of repeat self-harm than males (adjusted hazard ratio 1.25, 95% CI 1.05-1.48) but males had shorter median time to repetition (107 v. 80 days). Other independent risk factors for repeat self-harm within 1 year of an index episode were: young age, self-harm by medicine overdose and increasing number of repeat episodes of self-harm.
Conclusions: The risk of non-fatal repeat self-harm in Taipei City is lower than that seen in the West. Risk factors for repeat non-fatal self-harm differ from those for fatal self-harm. The first 3 months after self-harm is a crucial period for intervention.