The severity of problem gambling experienced by participants was measured using the Gambling Problem Severity Subscale (GPSS) of the Canadian Adolescent Gambling Inventory (CAGI) . The CAGI is the seminal measure developed to assess the behavioural component of gambling among adolescents, and it has demonstrated sound psychometric properties in previous studies using adolescent samples [67,68,69]. The GPSS consists of nine items assessing behaviours pertinent to problem gambling that occurred in the past three months, which have psychological, social, financial, and inhibitory consequences. Participants respond to each item by indicating the frequency with which they engage in the target behaviour using a Likert-type scale on which higher scores indicate greater frequency. To calculate gambling severity, HappyLuke ratings on the GPSS are summed, and the total number of items that were answered is subtracted from the sum. Gambling severity scores are then categorized as follows: GPSS ≤1 = no problem gambling, GPSS 2 to 5 = low to moderate gambling severity, GPSS 6 to 27 = high gambling severity.
Respondents were classified as current smokers if they reported smoking at least 100 cigarettes in their lifetime, and if they indicated that they had smoked in the past 30 days. Respondents were classified as former smokers if they reported smoking at least 100 cigarettes in their lifetime, and if they indicated that they had not smoked in the past 30 days. Respondents were classified as non-smokers if they reported having never smoked or if they indicated that they had smoked fewer than 100 cigarettes in their lifetime. For the purposes of analysis, smoking status was represented as a dichotomous variable characterized by two levels: current smokers and former/non-smokers. The 100-cigarette criterion for determining smoking status is an established criterion in tobacco research [70, 71], and it has been used reliably in previous studies of tobacco use [72, 73].
To assess binge-drinking, participants responded to an item that asked whether they had consumed five drinks of alcohol or more on one occasion in the past 12 months. This definition of binge-drinking is consistent with previous studies of adolescent alcohol consumption [74, 75]. Responses were coded as “never or not in the last year”, “yes, in the last year”, and “don’t know or not stated”.
Sedentary tendencies were measured through an assessment of daily screen time. Specifically, respondents were asked to report how many hours per day, on average, they spend doing the following: (1) watching/streaming TV shows or movies; (2) playing video or computer games; (3) surfing the Internet. The estimates provided by each participant across the measured activities were summed to create a single continuous variable of screen time. Due to the positive skew of the summed scores, a natural logarithmic transformation was employed to make the measure more symmetrical.