PROMIS® General Life Satisfaction scale: construct validity in musculoskeletal pain patients

BACKGROUND: Life satisfaction is part of subjective well-being. Measurement of life satisfaction is undertaken using self-report measures. This study aimed to evaluate the structural validity, concurrent validity, and internal structure of the PROMIS® General Life Satisfaction Scale (GLSS) in a musculoskeletal pain cohort. METHOD: Consecutive new patients attending the Victoria University Osteopathy Clinic (Melbourne, Australia) were invited to complete the GLSS prior to their initial consultation. Structural validity and internal structure were explored using confirmatory factor analysis and Mokken scale analysis. Concurrent validity was evaluated against a single-item measure of life satisfaction. RESULTS: The PROMIS® GLSS comprised a single factor and formed an acceptable Mokken scale in this population. No differential item functioning was observed. A large positive correlation (r = 0.70) was observed between the General Life Satisfaction scale and a single-item measure of life satisfaction. CONCLUSIONS: The PROMIS® General Life Satisfaction scale demonstrated acceptable internal structure and structural validity in a musculoskeletal pain population. Additional research is required to explore concurrent validity and other measurement properties, however initial data suggests the measure could be a feasible screen of life satisfaction for Australian osteopathic patients.