Zhongzhi Xu1,2, Jiannan Yang1, Qingpeng Zhang3, Paul S F Yip4. 1. School of Data Science, City University of Hong Kong, Hong Kong SAR, China. 2. Hong Kong Jockey Club Centre for Suicide Research and Prevention, The University of Hong Kong, Hong Kong SAR, China. 3. School of Data Science, City University of Hong Kong, Hong Kong SAR, China. qingpeng.zhang@cityu.edu.hk. 4. Hong Kong Jockey Club Centre for Suicide Research and Prevention, The University of Hong Kong, Hong Kong SAR, China. sfpyip@hku.hk.
Abstract
PURPOSE: The risk of death from suicide after self-poisoning has been known to be significantly higher as compared to the general population. Nevertheless, the change in suicide risk before and after self-poisoning is still unclear. METHODS: The database of territory-wide medical records collected by the Hospital Authority of Hong Kong was used to identify inpatients who have survived the first-ever self-poisoning but died by suicide between January 1, 2001, and December 31, 2010. A self-controlled case series ("SCCS") design controlling for time-invariant patient confounders was used to explore the temporal change in suicide risk after the first self-poisoning episode. RESULTS: During the study period, 227 people in the database died from suicide after surviving one episode of self-poisoning. A significant increase of the risk of suicide in the first 12 months after the first lifetime self-poisoning-Risk Ratio ("RR") 2.88 (95% CI 1.74-4.76)-was detected. The RR gradually returned to baseline levels after the second post-poisoning period. CONCLUSION: By within-person comparison, the net increase of the suicide risk caused by the first self-poisoning was quantitatively modeled, demonstrating that the first lifetime self-poisoning event itself is a modifiable risk factor of subsequent suicide death.
PURPOSE: The risk of death from suicide after self-poisoning has been known to be significantly higher as compared to the general population. Nevertheless, the change in suicide risk before and after self-poisoning is still unclear. METHODS: The database of territory-wide medical records collected by the Hospital Authority of Hong Kong was used to identify inpatients who have survived the first-ever self-poisoning but died by suicide between January 1, 2001, and December 31, 2010. A self-controlled case series ("SCCS") design controlling for time-invariant patient confounders was used to explore the temporal change in suicide risk after the first self-poisoning episode. RESULTS: During the study period, 227 people in the database died from suicide after surviving one episode of self-poisoning. A significant increase of the risk of suicide in the first 12 months after the first lifetime self-poisoning-Risk Ratio ("RR") 2.88 (95% CI 1.74-4.76)-was detected. The RR gradually returned to baseline levels after the second post-poisoning period. CONCLUSION: By within-person comparison, the net increase of the suicide risk caused by the first self-poisoning was quantitatively modeled, demonstrating that the first lifetime self-poisoning event itself is a modifiable risk factor of subsequent suicide death.
Entities:
Keywords:
Net change in risk of suicide; Poison-purchasing restrictions; Secondary suicide prevention; Self-controlled case series analysis; Self-harm; Self-poisoning