The suitability of the South Oaks Gambling Screen-Revised for Adolescents (SOGS-RA) as a screening tool: IRT-based evidence

The South Oaks Gambling Screen Revised for Adolescents (SOGS-RA) is one of the most widely used measures of adolescent gambling. We aimed to provide evidence of its suitability as a screening tool applying item response theory (IRT). The scale was administered to 981 adolescents (64% males; mean age = 16.57 years, SD = 1.63 years) attending high school. Analyses were carried out with a sample of 871 respondents, that is, adolescents who have gambled at least once during the previous year. Once the prerequisite of unidimensionality was confirmed through confirmatory factor analysis, unidimensional IRT analyses were performed. The 2-parameter logistic model was used in order to estimate item parameters (severity and discrimination) and the test information function. Results showed that item severity ranged from medium to high, and most of the items showed large discrimination parameters, indicating that the scale accurately measures medium to high levels of problem gambling. These regions of the trait were associated with the greatest amount of information, indicating that the SOGS-RA provides a reliable measure for identifying both problem gamblers and adolescents at risk of developing maladaptive behaviors deriving from gambling. The IRT-based evidence supports the suitability of the SOGS-RA as a screening tool in adolescent populations.