Psychometric testing of a self-administered, computerized adolescent drug and alcohol screening instrument

Objective: This study examined the psychometric properties of the Adolescent Drug and Alcohol Screening Instrument (ADASI) and its effect on youth knowledge and behavior. Method: Youth ages 12 to 15 (n=166) visiting a health clinic were assessed for drug and alcohol use and risk status using the ADASI (T1) and again at one week after the initial visit (T2). Internal consistency was examined using the coefficient á statistic. Test-retest reliability at one week was examined using Pearson correlations. To assess concurrent and external validity, the Problem-Oriented Screening Instrument for Teenagers (POSIT) was also administered at T1 and T2. POSIT scores were compared to ADASI scores and responses using nonparametric correlations. In addition, an effectiveness analysis compared youth at intake with posttest and 30-day follow-up (T3) measures of perceived risk of ATOD use; health information-seeking behaviors; and substance use behaviors and intentions. A pre/post design with 30-day follow-up was employed and analyses included paired-sample t-tests and nonparametric tests. Results: The ADASI showed good internal consistency at T1 and T2 (0.727, 0.746). Test-retest reliability was good, with a coefficient of stability of .603 (r). Concurrent and external validity of the ADASI was strong, with significant correlations with comparable screening questions, suggesting that the questions address risks relevant to substance use. The ADASI was effective in significantly increasing youths' perceived risks and information seeking behavior about ATOD use. Conclusions: Overall, the ADASI shows promise as a technically sound and user-friendly instrument for screening youth for substance use risk in community-based and healthcare settings.