Aim: The concurrent, construct and discriminative validity of the World Health Organization's Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) were examined in a multi-site international study.
Participants: One thousand and 47 participants, recruited from drug treatment (n = 350) and primary health care (PHC) settings (n = 697), were administered a battery of instruments.
Measurements: Measures included the ASSIST; the Addiction Severity Index-Lite (ASI-Lite); the Severity of Dependence Scale (SDS); the MINI International Neuropsychiatric Interview (MINI-Plus); the Rating of Injection Site Condition (RISC); the Drug Abuse Screening Test (DAST); the Alcohol Use Disorders Identification Test (AUDIT); the Revised Fagerstrom Tolerance Questionnaire (RTQ); and the Maudsley Addiction Profile (MAP).
Findings: Concurrent validity was demonstrated by significant correlations between ASSIST scores and scores from the ASI-Lite (r = 0.76-0.88), SDS (r = 0.59), AUDIT (r = 0.82) and RTQ (r = 0.78); and significantly greater ASSIST scores for those with MINI-Plus diagnoses of abuse or dependence (P < 0.001). Construct validity was established by significant correlations between ASSIST scores and measures of risk factors for the development of drug and alcohol problems (r = 0.48-0.76). Discriminative validity was established by the capacity of the ASSIST to discriminate between substance use, abuse and dependence. Receiver operating characteristic (ROC) analysis was used to establish cut-off scores with suitable specificities (50-96%) and sensitivities (54-97%) for most substances.
Conclusions: The findings demonstrated that the ASSIST is a valid screening test for identifying psychoactive substance use in individuals who use a number of substances and have varying degrees of substance use.