The interaction effect between low income and severe illness on the risk of death by suicide after self-harm.
BACKGROUND
Previous Western studies have reported that the prevalence of death by suicide within 1 year after self-harm was 0.5-2%; however, no studies have focused on the Far East.


OBJECTIVE
To calculate the prevalence of death by suicide after self-harm over different lengths of follow-up time and to determine the predictors of death by suicide after self-harm.


METHODS
Our study was based on 3,388 inpatients hospitalized between 2000 and 2007 in any of the 1,230 hospitals in Taiwan. Death by suicide after self-harm among the members of this cohort was tracked after 3 months, 6 months, and 1-8 years. The tracking continued until December 31, 2008. We analyzed the prevalence and risk factors of death by suicide after self-harm using Cox's regression model.


RESULTS
Of the 3,388 individuals with a history of self-harm included in the study, 48 (1.4%) died by suicide after self-harm within 3 months and 97 (2.9%) within 1 year. In all, 144 (4.3%) died by suicide after self-harm within 8 years. The predictors of death by suicide were violent methods (such as hanging, drowning, firearms, and jumping), low income, and severe illness. Moreover, an interaction effect was noted between low income and severe illness on the outcome (death by suicide).


CONCLUSIONS
It seems that effective healthcare for individuals who engage in self-harming behavior would benefit from supplementing medical care with social assistance, such as the support of a social worker.
<location>Graduate Institute of Life Sciences, National Defense Medical Center, Taiwan, Republic of China</location>
Chi-Hsiang
CH
Chung
Lu
L
Pai
Senyeong
S
Kao
Meei-Shyuan
MS
Lee
Tsung-Tsair
TT
Yang
Wu-Chien
WC
Chien
D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011203:Poverty / Q000523:psychology / Q000706:statistics & numerical data*; D015995:Prevalence; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D016728:Self-Injurious Behavior / Q000453:epidemiology* / Q000401:mortality; D012720:Severity of Illness Index; D013405:Suicide / Q000706:statistics & numerical data*; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult
National Health Insurance Research Database
                (NHIRD); follow-up; repeated self-harm; suicide