Substantial Clinical Benefit Thresholds for Hip Disability and Osteoarthritis Outcome Score Subscales and Associated Risk Factors for Nonattainment After Total Hip Arthroplasty: A Prospective Cohort Study of 9,229 Patients.

Abstract

The Centers for Medicare & Medicaid Services (CMS) now requires patient-reported outcome measures (PROMs) collection after total hip arthroplasty (THA), emphasizing substantial clinical benefit (SCB) in the Hip Disability and Osteoarthritis Outcome Score - Joint Replacement (HOOS-JR). This study aimed to establish SCB thresholds for HOOS Pain, Physical Function Short Form (PS), and JR, and to identify factors influencing SCB achievement after THA. A prospective analysis included 13,324 primary THAs performed between 2016 and 2022 at a tertiary healthcare institution. Of these, baseline PROMs were completed by 11,766 patients (88.3%), and one-year follow-up data were available for 9,229 patients (78.4%). Demographic characteristics, comorbidities, and PROMs data were collected, and patients were stratified into eight phenotypes based on pain, function, and mental health status. The SCB thresholds were calculated using anchor-based methods, anchored by the Veterans RAND-12 physical health question at one year. Multivariable logistic regression was conducted to determine factors linked to not achieving SCB. Established SCB thresholds were 40 for HOOS Pain (83.7% sensitivity, 45.3% specificity), 29.3 for HOOS-PS (75.4% sensitivity, 49.5% specificity), and 32.3 for HOOS-JR (79.3% sensitivity, 50.3% specificity). Overall, 72.8% of patients reached SCB. Factors significantly associated with failing to achieve SCB included non-White race, smoking, increased comorbidities, and worse baseline scores in pain, function, and mental health (P < 0.001). This study provides actionable benchmarks for HOOS domains following CMS mandates. Addressing disparities by incorporating preoperative phenotype stratification and risk mitigation strategies could optimize equitable outcomes after THA.