Factor structure of the Q-LES-Q short form in an enrolled mental health clinic population

PURPOSE: The Quality of Life, Enjoyment, and Satisfaction Questionnaire-Short Form (Q-LES-Q-SF) is a recovery-oriented, self-report measure with an uncertain underlying factor structure, variously reported in the literature to consist of either one or two domains. We examined the possible factor structures of the English version in an enrolled mental health population who were not necessarily actively engaged in care. METHODS: As part of an implementation trial in the U.S. Department of Veterans Affairs mental health clinics, we administered the Q-LES-Q-SF and Veterans RAND 12-Item Health Survey (VR-12) over the phone to 576 patients across nine medical centers. We used a split-sample approach and conducted an exploratory factor analysis (EFA) and multi-trait analysis (MTA). Comparison with VR-12 assessed construct validity. RESULTS: Based on 568 surveys after excluding the work satisfaction item due to high unemployment rate, the EFA indicated a unidimensional structure. The MTA showed a single factor: ten items loaded on one strong psychosocial factor (α = 0.87). Only three items loaded on a physical factor (α = 0.63). Item discriminant validity was strong at 92.3%. Correlations with the VR-12 were consistent with the existence of two factors. CONCLUSIONS: The English version of the Q-LES-Q-SF is a valid, reliable self-report instrument for assessing quality of life. Its factor structure can be best described as one strong psychosocial factor. Differences in underlying factor structure across studies may be due to limitations in using EFA on Likert scales, language, culture, locus of participant recruitment, disease burden, and mode of administration.