Development and Psychometric Properties of a New Patient-Reported Outcome Instrument of Health-Related Quality of Life Specific to Patients with Gambling Disorder: The Gambling Quality of Life Scale (GQoLS)

Background. Impairment or distress caused by gambling disorder can be subjectively assessed via quality of life. The aim of this study was to develop a new patient-reported outcome instrument to explore the health-related quality of life (HRQoL) in gambling disorders, the Gambling quality-of-life scale (GQoLS), and to document its psychometric properties. Methods. A previous qualitative study had been conducted using focus groups of problem gamblers to identify areas of HRQoL impacted by gambling. The seven domains identified served as the basis for the hypothetical structure of GQoLS. Draft items were generated from the patient's speeches to illustrate each of these domains. Cognitive debriefing interviews were realized to obtain a final hypothetical GQoLS. A validation study was then carried out to determine the final version of GQoLS and its psychometric properties (structural validity, construct validity, internal consistency). Results. The final GQoLS was composed of 21 items, with a total mean score of 38.3 (+/- 13.6). Structural validity found a major dimension and four other minor dimensions. The five dimensions were: "emotion", "lifestyle", "loneliness", "taboo" and "preoccupation". GQoLS was moderately to strongly correlated with PGSI and EQ-5D visual analogic scale. Cronbach's alpha coefficient was 0.92. Conclusion. GQoLS is the first HRQoL instrument specific to patients with a gambling disorder and developed from the patient's perspective. GQoLS presents good psychometric properties. GQoLS can be used in clinical research to demonstrate the effectiveness of an intervention on outcomes that are relevant from the patient's perspective.