Screening for problem gambling within mental health services: a comparison of the classification accuracy of brief instruments : Comparison of brief problem gambling screens

The Problem Gambling Severity Index (PGSI) is a widely used nine item scale for measuring the severity of gambling problems in the general population. Of the four gambler types defined by the PGSI, non-problem, low-risk, moderate-risk and problem gamblers, only the latter category underwent any validity testing during the scale's development, despite the fact that over 95% of gamblers fall into one of the remaining three categories. Using Canadian population data on over 25,000 gamblers, we conducted a comprehensive validity and reliability analysis of the four PGSI gambler types. The temporal stability of PGSI subtype over a 14-month interval was modest but adequate (intraclass correlation coefficient = 0.63). There was strong evidence for the validity of the non-problem and problem gambler categories however the low-risk and moderate-risk categories showed poor discriminant validity using the existing scoring rules. The validity of these categories was improved with a simple modification to the scoring system.

A large, integrated survey data set provided by the Ontario Problem Gambling Centre was used to investigate psychometric properties of the Problem Gambling Severity Index (PGSI). This nine-item self-report instrument was designed to measure a single, problem gambling construct. Unlike its nearest competitor--the South Oaks Gambling Screen (SOGS)--the PGSI was designed specifically for use with a general population rather than in a clinical context. The present analyses demonstrated that the PGSI does assess a single, underlying, factor, but that this is complicated by different, multiple factor structures for respondents with differing levels of problem gambling severity. The PGSI also demonstrated small to moderate correlations with measures of gambling frequency and faulty cognitions. Overall, the PGSI presents a viable alternative to the SOGS for assessing degrees of problem gambling severity in a non-clinical context.