To examine the relationship between gambling behaviours and risk of gambling-related harm in a nationally representative population sample.
Risk curves of gambling frequency and expenditure (total amount and percentage of income) were plotted against harm from gambling.
Data derived from 19012 individuals participating in the Canadian Community Health Survey—Mental Health and Well-being cycle, a comprehensive interview-based survey conducted by Statistics Canada in 2002.
Gambling behaviours and related harms were assessed with the Canadian Problem Gambling Index.
Risk curves indicated the chances of experiencing gambling-related harm increased steadily the more often one gambles and the more money one invests in gambling. Receiver operating characteristic analysis identified the optimal limits for low-risk participation as gambling no more than two to three times per month, spending no more than $501–1000CAN per year on gambling and investing no more than 1% of gross family income on gambling activities. Logistic regression modelling confirmed a significant increase in the risk of gambling-related harm (odds ratios ranging from 2.0 to 7.7) when these limits were exceeded.
Risk curves are a promising methodology for examining the relationship between gambling participation and risk of harm. The development of low-risk gambling limits based on risk curve analysis appears to be feasible.