Weekly lottery sales volume and suicide numbers: A time series analysis on national data from Taiwan

Objective: To investigate the association between weekly lottery sales and number of suicide deaths in Taiwan. Methods: All suicides aged 15+ years during 2004-2006 in Taiwan were included. Poisson autoregression time series models investigated associations of weekly numbers with contemporaneous and recent sales from two national lotteries in operation. Adjustments were made for seasonal fluctuation, temperature, monthly unemployment and autocorrelation. Results: In fully adjusted models, suicide deaths were negatively correlated with sales of tickets for a low-prize, low-cost lottery system. However, they were correlated positively with recent sales for a higher-cost, larger-prize system. Both correlations were stronger for male than female suicide numbers but differed in terms of age groups most strongly implicated. Conclusions: Associations between lottery sales and suicide numbers differed according to the nature of the lottery. A low-prize, low-publicity system appeared to be more benign than a high-prize, high-publicity one.