Asking about the last four drinking occasions on a tablet computer as a way to record alcohol consumption in Aboriginal and Torres Strait Islander Australians: a validation

BACKGROUND: Alcohol consumption among Indigenous Australians can be irregular, depending on social and geographic context. The Finnish method uses the last four drinking occasions to estimate drinking quantity and pattern. The Grog Survey App is an interactive and visual tablet computer application which uses touch-screen technology to deliver questions on drinking. METHODS: Alcohol consumption recorded on the Grog Survey App using the last four occasions (Finnish) method was compared with a clinical interview conducted by an Indigenous Australian health professional. To assess convergent validity, Spearman's ranked correlations between consumption estimates from the App and from interview were calculated. Sensitivity and specificity analyses were used to compare how well the App and clinical interview agreed when classifying drinkers' risk. To assess criterion validity, average grams alcohol per day as estimated by the App (and by interview) were compared against presence of self-reported withdrawal tremors (from App or interview). Test-retest reliability was assessed by correlations between measures of alcohol consumption recorded on two occasions. RESULTS: The App recorded higher numbers of standard drinks consumed per drinking occasion than the interview. There was reasonable agreement between the App and interview across common reference periods (sensitivity 92.7%, specificity 69.8%, short-term risk; sensitivity 70.7%, specificity 68.8%, long-term risk). Average consumption recorded by the App was as good or better predictor of withdrawal tremors than consumption as estimated by interview. CONCLUSIONS: The Finnish method, as delivered by the App, offers an innovative way to collect survey data on alcohol in a population with an intermittent drinking pattern.