A randomized controlled trial of a brief intervention for alcohol and drugs linked to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) in primary health care in Chile.

AIM: To study the effectiveness of a brief intervention (BI) associated with the ASSIST (Alcohol Smoking and Substance Involvement Screening Test) for alcohol and illicit drug use as part of a systematic screening program implemented in primary care.

DESIGN: A multi-center randomized open-label trial stratified using the ASSIST-specific substance involvement score (for alcohol, scores ranged from 11 to 15 and 16 to 20; and for the other substances from 4 to 12 and 13 to 20).

SETTING: A total of 19 primary care centers (n = 520), eight emergency rooms (n = 195) and five police stations (n = 91) were evaluated.

PARTICIPANTS: A total of 12 217 people aged between 19 and 55 years were screened for moderate alcohol and drug use risk as defined by the ASSIST Chilean version. A total of 806 non-treatment-seekers were randomized.

INTERVENTION AND COMPARISON: ASSIST-linked BI (n = 400) compared with an informational pamphlet on risk associated with substance use (n = 406).

MEASUREMENTS: Total ASSIST alcohol and illicit involvement score (ASSIST-AI), and ASSIST-specific score for alcohol, cannabis and cocaine at baseline and at 3-month follow-up.

FINDINGS: Sixty-two per cent of participants completed follow-up. An intention-to-treat analysis showed no difference between the two groups for the ASSIST-AI score [mean difference (MD) = - 0.17, confidence interval (CI) = -1.87, 2.20], either for specific scores alcohol (MD = 0.18, CI = -1.45, 1.10), cannabis (MD = -0.62, CI = -0.89, 2.14) or cocaine (MD = -0.79, CI = -2.89, 4.47).

CONCLUSION: It is not clear whether a brief intervention associated with the Alcohol Smoking and Substance Involvement Screening Test is more effective than an informational pamphlet in reducing alcohol and illicit substance consumption in non-treatment-seeking, primary care users with moderate risk.