Abstract
OBJECTIVE: Centers for Medicare and Medicaid Services (CMS) has requested hospitals collect and report patient-reported outcomes (PROs) beginning in 2024 including the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS-JR). However, scale structural validity of the HOOS-JR has minimally been assessed. The purpose of this study was to assess internal consistency, structural validity, and multi-group invariance properties of the HOOS-JR in a large sample of patients who underwent a total hip arthroplasty (THA). METHODS: A cross-sectional study using the Surgical Outcomes System was retrospectively queried for patients who underwent a THA. Internal consistency was assessed using Cronbach's alpha and McDonald's Omega. A confirmatory factor analysis (CFA) was performed on the HOOS-JR using a priori cut-off values. Multi-group invariance testing was also performed on the sample of patients across sex and age groups. RESULTS: Internal consistency was acceptable for 6-item (alpha = 0.88; omega = 0.88) and 5-item (alpha = 0.86; omega = 0.86) HOOS-JR. The one-factor, 6-item CFA did not meet the recommended fit indices. The one-factor, 5-item CFA had acceptable fit for the sample data. Invariance testing criteria were met between the age groups; however, scalar invariance was not met for sex. CONCLUSION: The 6-item HOOS-JR did not meet contemporary model fit indices indicating that scale refinement is warranted. The 5-item met most goodness-of-fit indices and invariance criteria. However, further scale refinement may be warranted as localized fit issues were identified.