Psychometric validation of the Japanese version of Alcohol Quality of Life Scale (AQoLS-Japan) in the treatment of patients with alcohol use disorder

Abstract

Purpose: The Alcohol Quality of Life Scale (AQoLS) is accepted as a useful measure in assessing impact of alcohol use disorders (AUD) on health-related quality of life (HR-QoL) in Western cultures. We aimed to assess the psychometric properties of the Japanese version of the AQoLS (AQoLS-Japan). Methods: This was a 3-month, observational cohort study in patients undergoing routine treatment for AUD in Japan. HR-QoL was assessed using the AQoLS-Japan (34 items, 7 dimensions). Scale psychometrics were analyzed using correlative techniques. Results: Data from 132 patients were analyzed. Inter-item and item-scale correlations for the AQoLS-Japan scale were moderate to strong. Confirmatory factor analysis results supported the AQoLS-Japan structure but there was evidence of interdependency among some items and factors. Cronbach’s alpha coefficients for internal consistency ranged from 0.73 to 0.97, and intraclass correlation coefficients for scores between test (baseline) and retest (2 weeks) ranged from 0.65 to 0.82. Convergent and divergent validity and known-groups validity were supported. Evaluation of within-group change demonstrated that the AQoLS-Japan total and domains consistently demonstrated statistically significant improvement (p < 0.001 in all cases) in HR-QoL over time. Estimates for minimal clinically important difference on the AQoLS-Japan total score ranged from 13.2 to 18.2 for group-level change and from 2.4 to 15.7 for a group-level difference. Conclusions: The AQoLS-Japan is a reliable and valid measure of HR-QoL that is able to demonstrate benefits associated with the routine treatment of AUD in Japan.