Risk factors of suicide mortality among multiple attempters: A national registry study in Taiwan

Little is known about the risk factors of suicide mortality among multiple attempters. This study aims to investigate the predictors of suicidal mortality in a prospective cohort of attempters in Taiwan, focusing on the time interval and suicide method change between the last two nonfatal attempts. Methods: The representative data retrieved from the National Suicide Surveillance System (NSSS) was linked with National Mortality Database to identify the causes of death in multiple attempters during 2006–2008. Cox-proportional hazard models were applied to calculate the hazard ratios for the predictors of suicide. Results: Among the 55,560 attempters, 6485 (11.7%) had survived attempts ranging from one to 11 times; 861 (1.5%) eventually died by suicide. Multiple attempters were characterized by female (OR = 1.56, p < 0.0001), nonrecipient of national aftercare service (OR = 1.62, p < 0.0001), and current contact with mental health services (OR = 3.17, p < 0.0001). Most multiple attempters who survived from hanging (68.1%) and gas poisoning (61.9%) chose the same method in the following fatal episode. Predictors of suicidal death were identified as male, older age (≥ 45 years), shorter interval and not maintaining methods of low lethality in the last two nonfatal attempts. Receipt of nationwide aftercare was associated with lower risk of suicide but the effect was insignificant. Conclusion: The time interval of the last two nonfatal attempts and alteration in the lethality of suicide method were significant factors for completed suicide. Risk assessment involving these two factors may be necessary for multiple attempters in different clinical settings. Effective strategies for suicide prevention emphasizing this high risk population should be developed in the future