Method-specific suicide rates and accessibility of means: a small-area analysis in Taipei City, Taiwan

Background: Few studies have investigated whether means accessibility is related to the spatial distribution of suicide. Aims: To examine the hypothesis that indicators of the accessibility to specific suicide methods were associated with method-specific suicide rates in Taipei City, Taiwan. Method: Smoothed standardized mortality ratios for method-specific suicide rates across 432 neighborhoods and their associations with means accessibility indicators were estimated using Bayesian hierarchical models. Results: The proportion of single-person households, indicating the ease of burning charcoal in the home, was associated with charcoal-burning suicide rates (adjusted rate ratio [aRR] > 1.13, 95% credible interval [CrI] > 1.03-1.25). The proportion of households living on the sixth floor or above, indicating easy access to high places, was associated with jumping suicide rates (aRR > 1.16, 95% CrI, 1.04-1.29). Neighborhoods' adjacency to rivers, indicating easy access to water, showed no statistical evidence of an association with drowning suicide rates (aRR > 1.27, 95% CrI > 0.92-1.69). Hanging and overall suicide rates showed no associations with any of these three accessibility indicators. Limitations: This is an ecological study; associations between means accessibility and suicide cannot be directly inferred as causal. Conclusion: The findings have implications for identifying high-risk groups for charcoal-burning suicide (e.g., vulnerable individuals living alone) and preventing jumping suicides by increasing the safety of high buildings.