Validation of a new patient-reported outcome instrument of health-related quality of life specific to patients with alcohol use disorder: the Alcohol Quality of Life Scale (AQoLS)

Abstract

PURPOSE: The Alcohol Quality of Life Scale (AQoLS) is a new patient-reported outcome 34-item questionnaire measuring health-related quality of life (HRQOL), specific to patients with an alcohol use disorder, developed from the patients' perspective. This is the first report establishing evidence in support of measurement reliability and validity of the AQoLS. METHODS: A total of 285 randomly selected patients receiving interventions for alcohol use disorder in addiction specialised care settings in France were included in the study (response rate 80.1 %). Exploratory factor analysis was conducted to evaluate the hypothesised-during-development-stage dimensional structure of the AQoLS. Internal consistency of the total score and the dimensions subscores were assessed through Cronbach's alpha coefficients. Construct validity was tested through correlations with the Short-Form 36 Health Survey (SF-36) and EuroQol 5 dimensions (EQ-5D). RESULTS: Exploratory analysis indicated seven observed dimensions which differed slightly from the 7 dimensions defined a priori in the framework hypothesised during the scale development: activities, relationships, living conditions, negative emotions, self-esteem, control and sleep. A major common factor allows the summing of the 34 items to obtain a total score. All the 34 items were acceptable. Cronbach's alpha for the AQoLS total score was 0.96 and ranged from 0.8 to 0.9 for the dimensions subscores. Negative correlations between AQoLS and all dimensions of the SF-36, but general health and positive correlations between AQoLS and all items of the EQ-5D were shown. As expected, the correlations were mostly moderate in magnitude, low with scores referring to physical areas and the highest with the SF-36 MSC. CONCLUSION: This study provides evidence of the measure's psychometric properties in terms of construct validity and internal consistency. The 'control' and 'self-esteem' dimensions are of particular interest as these concepts are not captured in existing HRQOL. Further longitudinal validation of the scale is necessary to assess sensitivity to change