Abstract
Repetition of deliberate self harm is an important predictor of subsequent suicide. Repetition rates in Asian countries appear to be significantly lower than in western high income countries. The reason for these reported differences is not clear and has been suggested to due methodological differences or the impact of access to more lethal means of self harm. This prospective study determines the rates and demographic pattern of deliberate self-poisoning, suicide and fatal and non fatal repeated deliberate self-poisoning in rural Sri Lanka. Details of deliberate self poisoning admission in all hospitals (n=46) and suicides reported to all the police stations (n=28) of a rural district were collected for 3 years, 2011-2013. Demographic details of the cohort of deliberate self-poisoning patients admitted to all hospitals in 2011 (N=4022), were screened to link with patient records and police reports of successive two years with high sensitivity using a computer program and manual matching was performed with higher specificity. Life time repetition was assessed in a randomly selected subset of DSP patients (n=438). There were 15,914 DSP admissions and 1078 suicides during the study period. Within the study area the deliberate self poisoning and suicide population incidences were, 248.3/100,000 and 20.7/100,000 in 2012. Repetition rate for four weeks, one-year and two-years were 1.9% (95% CI 1.5-2.3%), 5.7% (95% CI 5.0 to 6.4) and 7.9% (95% CI 7.1 to 8.8) respectively. The median interval between two attempts were 92 (IQR 10 - 238) and 191 (IQR 29 - 419.5) days for the one and two-year repetition groups. The majority of patients used the same poison in the repeat attempt. Age and hospital stay of individuals with repetitive events were not significantly different from those who had no repetitive events. The two-year rate for suicide following DSP was 0.7% (95% CI 0.4-0.9%). Reported life time history of deliberate self harm attempts was 9.5% (95% CI 6.7-12.2%). The low comparative repetition rates in rural Sri Lanka was not explained by higher rates of suicide or access to more lethal means or differences in methodology.
