Association between the accessibility to lethal methods and method-specific suicide rates: An ecological study in Taiwan

Objective: To examine the association between availability of lethal methods of suicide and method-specific suicide rates at the city/county level in Taiwan. Method: Age-adjusted and age-specific suicide rates of 23 cities/counties in Taiwan for the years 1999 to 2003 were calculated. Partial correlation coefficients were used to examine cross-sectional associations between independent variables, i.e., proportion of agricultural population and proportion of households living on the sixth floor or above; and suicide rates by different methods (poisoning by solids/liquids, jumping, and hanging) after adjusting for unemployment rates and prevalence of depression. Results: The partial correlation coefficient was 0.77 (p <.001). for proportion of agricultural population with solids/liquids poisoning suicide rates. It was 0.73 (p <.001) for the proportion of households living on the sixth floor or above with suicide rates by jumping. Correlations between hanging suicide rates and proportion of agricultural population or between hanging suicide rates and proportion of households living on the sixth floor or above were not significant. Conclusion: The results showed strong positive associations between access to lethal methods and method-specific suicide rates. Controlling the availability of pesticides and fencing high buildings or installing window guards may be effective measures for suicide prevention.