Generalizability of the findings from a randomized controlled trial of a web‐based substance use disorder intervention

Background and Objectives There is growing concern regarding the generalizability of findings from randomized controlled trials (RCTs) of interventions for substance use disorders (SUDs). This study used a selection model approach to assess and improve the generalizability of an evaluation for a web‐based SUD intervention by making the trial sample resemble the target population. Methods The sample of the web‐based SUD intervention (Therapeutic Education System vs. Treatment‐as‐usual; n = 507) was compared with the target population of SUD treatment‐seeking individuals from the Treatment Episodes Data Set‐Admissions (TEDS‐A). Using weights based on the probabilities of RCT participation, we computed weighted treatment effects on retention and abstinence. Results Substantial differences between the RCT sample and the target population was demonstrated in significant difference in the mean propensity scores (1.62 standard deviations at p