Characteristics of overdose and non-overdose suicide attempts in a multi-ethnic Asian society.

BACKGROUND: Overdosing is an accessible method adopted by people attempting suicide in city settings.

AIMS: This study aimed to compare the trends and characteristics of people attempting suicide by drug overdose and by other methods in Singapore.

METHODS: This study examined the medical records of 628 patients who were admitted to a university hospital in Singapore, between January 2004 and December 2006. Patients were classified as overdose and non-overdose persons attempting suicide for comparisons of demographic and suicidal characteristics. Logistic regression was used to determine the odds ratios of various factors associated with self-perceived lethality of the suicide attempt. Patterns of monthly and weekly variations in the frequencies of suicide attempts were also analyzed.

RESULTS: The percentages of Chinese people was higher in the non-overdose group (71.5% vs. 62.9%), while the percentages of Malay and Indian people were higher in the overdose group (31.6% vs. 18.5%). The female gender (OR=0.36, p=0.04) and admission of suicide intention (OR=7.11, p<0.001) were significantly associated with higher perceived lethality of the suicide method in the non-overdose group. Suicide attempts occurred more frequently between May and November, and on Tuesdays.

CONCLUSIONS: Gender and ethnic differences between overdose and non-overdose people attempting suicide were found. Temporal variations of suicidal cases were also noted.