Reliability of the GAIN-SS, CRAFTT and PESQ screening instruments for substance use among South African adolescents

Screening for adolescent substance use can assist with the early identification of substance-related problems and guide the provision of appropriate services. As such, psychometrically sound screening tools are needed. The aim of this study was to compare the reliability of the CRAFFT, Global Appraisal of Individual Needs-Short Screener (GAIN-SS) substance use subscale and Personal Experience Screening Questionnaire (PESQ) among adolescents from disadvantaged communities in Cape Town, South Africa.

Adolescents aged 12-19 years (n = 231) completed the three screeners at two points in time.

Findings show that all three of the screeners had adequate internal consistency (Cronbach α ≥ 0.8). Test-retest reliability was similar for all three screeners, with intraclass correlation coefficient values slightly higher for the PESQ (0.82, 95% CI: 0.77-0.86) than for the GAIN-SS substance use subscale (0.79, 95% CI: 0.73-0.84) and CRAFFT (0.76; 95% CI: 0.66-0.83). Kappa values indicated that the GAIN-SS substance use subscale and CRAFFT had moderate levels of agreement, while the PESQ had substantial levels of agreement for identifying those who had moderate or higher substance use risks at Time 1 and Time 2.

The findings indicate that all of these short screeners seem to have acceptable reliability when used in this population. All of the three screeners are appropriately reliable when used with adolescents from disadvantaged communities in Cape Town, but the PESQ performed slightly better. Future studies should also include the assessment of validity of these screeners in this context.