Methods of suicide predict the risks and method-switching of subsequent suicide attempts: a community cohort study in Taiwan

Abstract

Objective

Suicide is a major public health concern. This study aimed to determine the predictors of repeated suicide attempts, focusing on whether lethality level of the suicidal method predicts the risk of subsequent suicide attempts.

Methods

All consecutive individuals (N=2,070) with an episode of nonfatal self-harm registered in a surveillance database provided by the Department of Health of Keelung City Government in Taiwan from January 1, 2006 to December 31, 2010 were enrolled and followed up until the end of 2011. The earliest attempt recorded in the database was defined as the index attempt. Subjects were classified according to suicide method into low-lethal and high-lethal groups. Data on time of and methods chosen for subsequent suicide attempts during the follow-up period were analyzed.

Results

Of the total people screened for the study, 18.1% made a repeated suicide attempt. Subjects in the high-lethal group were more likely to be male; aged 35–64 years; and single, divorced, or widowed. Compared to other time intervals, most subsequent suicide attempts occurred within 6 months from the index attempt. The independent predictors for repeated suicide attempts were the use of low-lethal methods in the index attempt and being 35–49 years old. Using high-lethal methods and being older than 50 years were associated with changing suicide method for the second attempt.

Conclusion

Lethality level of former suicidal method could predict repeated suicide attempts and changing of suicide methods. Further clarification is needed on whether a higher risk of repeat attempts is associated with higher rates of suicide mortality.

Keywords:

• lethality
• method of suicide
• suicide repetition
• risk factor
• survival analysis

Acknowledgments

The authors express their deepest gratitude to the Department of Health, Keelung City Government, for providing the suicide data. This study was supported by the Chang Gung Memorial Hospital Research Project (CZRPG290021).

Author contributions

YCH participated in interpreting data, reviewing references, and drafting the manuscript. YWW, CKC, and LJW participated in the design of study. LJW executed the statistical analysis and drafted and revised the manuscript. All authors read and approved the final manuscript and contributed to the drafting and revising of the paper.

Disclosure

The authors report no conflicts of interest in this work.