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.
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.
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).
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.
Keywords: Repeated self-harm, Follow-up, National Health Insurance Research Database (NHIRD)



2
publication history
16, and rare diseases), and psychiatric disorders (two groups consisting of patients with/without psychiatric disorders in accordance with the ICD-9-CM N-Code 209-319).