Open Access Research article

A nationwide, population-based, long-term follow-up study of repeated self-harm in Taiwan

Chi-Hsiang Chung1, Ching-Huang Lai2, Chi-Ming Chu2, Lu Pai3, Senyeong Kao2 and Wu-Chien Chien2*

Author Affiliations

1 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

2 School of Public Health, National Defense Medical Center, No. 161, Section 6, Min-Chuan East Road, Neihu District, Taipei City 11490, Taiwan, Republic of China

3 Taiwan Injury Prevention & Safety Promotion Association, Room 4112, No. 161, Section 6, Min-Chuan East Road, Neihu District, Taipei City 11490, Taiwan, Republic of China

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BMC Public Health 2012, 12:744 doi:10.1186/1471-2458-12-744

Published: 6 September 2012

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.

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