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 10632 Australian adults, 3120 Canadian adults, 4484 people aged 15-74years in Finland and 5235 people aged 15-74years 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 losses²⁼-7.6 (95% CI=-17.5, -4.5)}, Canada [β losses=2.0 (95% CI=1.3, 3.9), β losses²⁼-3.9 (95% CI=-15.4, -2.2)] and Finland [β losses=3.6 (95% CI=2.5, 7.5), β losses²⁼-4.4 (95% CI=-34.9, -2.4)] and linear in Norway [β losses=1.6 (95% CI=0.6, 3.1), β losses²⁼-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.