The relationship between player losses and gambling-related harm: evidence from nationally representative cross-sectional surveys in four countries.

Background and Aims Flaws in previous studies mean that findings of J-shaped risk curves for gambling should be disregarded. The current study aims to estimate the shape of risk curves for gambling losses and risk of gambling-related harm (a) for total gambling losses and (b) disaggregated by gambling activity. Design Four cross-sectional surveys. Setting Nationally representative surveys of adults in Australia (1999), Canada (2000), Finland (2011) and Norway (2002). Participants A total of 10 632 Australian adults, 3120 Canadian adults, 4484 people aged 15-74 years in Finland and 5235 people aged 15-74 years in Norway. Measurements Problem gambling risk was measured using the modified South Oaks Gambling Screen, the NORC DSM Screen for Gambling Problems and the Problem Gambling Severity Index. Findings Risk curves for total gambling losses were estimated to be r-shaped in Australia {β losses = 4.7 [95% confidence interval (CI) = 3.8, 6.5], β losses^{2 =} -7.6 (95% CI = -17.5, -4.5)}, Canada [β losses = 2.0 (95% CI = 1.3, 3.9), β losses^{2 =} -3.9 (95% CI = -15.4, -2.2)] and Finland [β losses = 3.6 (95% CI = 2.5, 7.5), β losses^{2 =} -4.4 (95% CI = -34.9, -2.4)] and linear in Norway [β losses = 1.6 (95% CI = 0.6, 3.1), β losses^{2 =} -2.6 (95% CI = -12.6, 1.4)]. Risk curves for different gambling activities showed either linear, r-shaped or non-significant relationships. Conclusions Player loss-risk curves for total gambling losses and for different gambling activities are likely to be linear or r-shaped. For total losses and electronic gaming machines, there is no evidence of a threshold below which increasing losses does not increase the risk of harm. [ABSTRACT FROM AUTHOR]