Clinically Relevant Threshold Achievement Evolves Over Time Following Primary Total Hip Arthroplasty
Author(s):Cohen MF, Walsh EG, Patel DH, Quesada-Jimenez R, Kuhns BD, Domb BG.
DOI Link: 10.1016/j.arth.2026.03.018
Background
Clinically relevant outcome thresholds such as the patient acceptable symptom state (PASS) and minimum clinically important difference (MCID) enhance interpretation of patient-reported outcomes following total hip arthroplasty (THA). However, how these thresholds evolve over time remains unclear.
Methods
A retrospective review was conducted on 221 hips undergoing primary THA with complete 2- and 5-year follow-up. PASS thresholds for mHHS, HOOS-JR, VAS, and Forgotten Joint Score (FJS) were calculated using ROC analysis. MCID for mHHS and VAS was determined using a distribution-based method. Threshold achievement rates were compared between timepoints.
Key Findings
PASS thresholds decreased over time, reflecting lower functional expectations at 5 years compared to 2 years.
PASS achievement rates increased from 2 to 5 years, significantly for mHHS (76% → 84.6%; P < .01).
At 2 years, PASS thresholds/achievement rates were: mHHS 88.0 (76%), HOOS-JR 71.9 (85.5%), FJS 53.1 (89.1%), VAS 2.5 (84.6%).
At 5 years: mHHS 75.0 (86.4%), HOOS-JR 60.4 (91.0%), FJS 51.0 (86.9%), VAS 2.3 (83.3%).
MCID achievement rates remained stable between 2 and 5 years for mHHS and VAS (P > .05).
Conclusion
PASS thresholds and achievement rates evolve over time following THA, with increasing rates of patient-acceptable outcomes despite lower functional threshold values. MCID achievement remains consistent.
What Does This Mean for Providers?
Providers should recognize that patient expectations and perceptions of acceptable outcomes shift over time following THA. Lower PASS thresholds at longer follow-up may reflect adaptation and aging, while increasing PASS achievement suggests improved patient satisfaction. Longitudinal interpretation of PROs should account for these temporal changes when assessing outcomes and counseling patients.