Measuring recovery among people who have completed residential rehabilitation: Factor structure and scoring of the substance use recovery evaluator.

Introduction: The substance use recovery evaluator (SURE) is a new patient-reported outcome measure of recovery from alcohol and other drugs. The original SURE validation study did not include clients from residential rehabilitation treatment, and the possible challenges in applying the measure in this setting were noted. This study evaluates the factor structure and scoring of the substance use recovery evaluator for people after discharge from residential alcohol and other drug rehabilitation in Australia.

Methods: Two hundred and twenty-five participants interviewed at 14 weeks post-discharge from residential rehabilitation between 2018 and 2020 were included in a cross-sectional analysis of longitudinal data. Item response theory statistics (IRT) were used to determine optimal scoring methods for the SURE. Confirmatory factor analysis (CFA) models were used to confirm the SURE's factor structure.

Results: An initial CFA of the 5-factor model using original scoring could not be fitted. Although IRT indicated a combination of binary and three-point scale scoring could be used, a binary scale included most of the information from other response categories, and CFA using a Bayes estimation to confirm the original structure with binary data indicated good model fit, p = 0.164.

Discussion and conclusions: The SURE has the same five underlying factors identified by the original study, each of which provides important clinical information about recovery. Binary rescoring provides a valid, parsimonious and clinically relevant way of measuring substance use recovery for residential treatment populations post-discharge.