BACKGROUND AND AIMS Although remote drug/alcohol interventions have been widely reviewed, their effectiveness specifically for people in treatment remains unclear. We aimed to systematically review the effectiveness of remote interventions (delivered by telephone or computer) in alcohol/drug treatment and recovery support.

METHODS We searched 29 databases including Medline and PsycINFO for randomised controlled trials (RCTs) of remote interventions for adults diagnosed with alcohol/drug use disorder conducted in Organization for Economic Co-operation and Development (OECD) countries published 2004-2023. We grouped interventions according to whether they supplemented or replaced/partially replaced in-person care. We used random effects meta-analyses to estimate pooled odds ratios (OR) for relapse, and standardised mean differences (SMD) for days of alcohol/drug use. We appraised outcomes using Cochrane Risk of Bias 2.

RESULTS We identified 34 RCTs (6461 participants) evaluating 42 remote interventions, with diverse therapeutic approaches. Over 70% of outcomes were judged to be at high risk-of-bias. When remote interventions supplemented in-person care, there was a 39% lower odds of relapse [17 interventions; OR 0.61; 95% confidence interval (CI) = 0.46, 0.81; P = 0.001; I = 40.3%) and a reduction in the mean days of use (17 interventions; SMD -0.18; 95% CI = -0.28 to -0.08; P = 0.001; I = 27.3%) compared with in-person care alone. When remote interventions replaced/partially replaced in-person care, there was a 49% lower odds of relapse (7 interventions; OR 0.51; 95% CI = 0.34, 0.76; P = 0.001; I = 39.7%) and a very slight and uncertain reduction in mean days of use (8 interventions; SMD -0.08; 95% CI = -0.24 to 0.07; P = 0.301; I = 48.4%) compared with in-person care. Subgroup analyses by type of substance and therapeutic approach were mixed and inconclusive.

CONCLUSIONS Remote interventions which supplement in-person alcohol/drug treatment appear to reduce relapse and days of use. The evidence is less conclusive regarding remote interventions that replace/partially replace in-person care due to a smaller body of evidence and uncertainty (days of use). High risk-of-bias means findings should be interpreted with caution.