title: A nationwide, population-based, long-term follow-up study of repeated self-harm in Taiwan.
abstract: BACKGROUND
  Previous follow-up studies of repeated self-harm show that the cumulative risk of repeated self-harm within one year is 5.7%-15%, with females at greatest risk. However, relatively few studies have focused on the Far East. The objective of this study was to calculate the cumulative risk of repeated self-harm over different lengths of follow-up time (3 months, 6 months, and 1-8 years), to determine factors influencing repeated self-harm and to explore the interaction between gender and self-harm methods.
  
  
  METHODS
  We used self-harm patient who hospitalized due to first-time self-harm between 2000 and 2007 from 1,230 hospitals in Taiwan. Hospitalization for repeated self-harm among members of this cohort was tracked after 3 months, 6 months, and 1-8 years. Tracking continued until December 31, 2008. We analyzed the cumulative risk and risk factors of repeated self-harm by using negative binomial regression.
  
  
  RESULTS
  Of the 39,875 individual study samples, 3,388 individuals (8.50%) were found to have repeatedly self-harmed. The cumulative risk of repeated self-harm within three months was 7.19% and within one year was 8%. Within 8 years, it was 8.70%. Females were more likely to repeatedly self-harm than males (RR = 1.21, 95% CI = 1.15-1.76). The main method of self-harm was solid or liquid substances (RR = 1.88, 95% CI = 1.23-2.04) or cutting or piercing (RR = 1.36, 95% CI = 1.02-1.82), and in patients with psychiatric disorders were more likely to self-harm (RR = 1.61, 95% CI = 1.48-1.75).
  
  
  CONCLUSIONS
  The key time for intervention for repeated self-harm is within three months. Appropriate prevention programs should be developed based on gender differences.
authors.affiliation: Graduate Institute of Life Sciences, National Defense Medical Center, No. 161, Section 6, Min-Chuan East Road, Neihu District, Taipei City 11490, Taiwan, Republic of China.
authors.forename: Chi-Hsiang
authors.initials: CH
authors.lastname: Chung
authors.forename: Ching-Huang
authors.initials: CH
authors.lastname: Lai
authors.forename: Chi-Ming
authors.initials: CM
authors.lastname: Chu
authors.forename: Lu
authors.initials: L
authors.lastname: Pai
authors.forename: Senyeong
authors.initials: S
authors.lastname: Kao
authors.forename: Wu-Chien
authors.initials: WC
authors.lastname: Chien
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology*; D012737:Sex Factors; D013406:Suicide, Attempted / Q000706:statistics & numerical data; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult