RESUMEN
OBJECTIVES: To determine the test-retest reliability, concurrent, convergent, and discriminant validity of a recently devised screen (the Newton screen) for alcohol and cannabis use/misuse, and its predictive validity at follow-up. STUDY DESIGN: Adolescents, 12-17 years old (n = 4898), treated in 1 of 16 participating pediatric emergency departments across the US were enrolled in a study as part of a larger study within the Pediatric Emergency Care Applied Research Network. Concurrent and predictive validity (at 1, 2, and 3 years of follow-up) were assessed in a random subsample with a structured Diagnostic and Statistical Manual of Mental Disorders-based interview. Convergent validity was assessed with the Alcohol Use Disorders Identification, a widely used alcohol screening measure. RESULTS: The sensitivity of the Newton screen for alcohol use disorder at baseline was 78.3% with a specificity of 93.0%. The cannabis use question had a baseline sensitivity of 93.1% and specificity of 93.5% for cannabis use disorder. Predictive validity analyses at 1, 2, and 3 years revealed high specificity but low sensitivity for alcohol and high specificity and moderate sensitivity for cannabis. CONCLUSIONS: The Newton screening instrument may be an appropriate brief screening tool for use in the busy clinical environment. Specificity was high for both alcohol and cannabis, but sensitivity was higher for cannabis than alcohol. Like other brief screens, more detailed follow-up questions may be necessary to definitively assess substance misuse risk and the need for referral to treatment.