Patient acceptable symptom state and OMERACT-OARSI set of responder criteria in joint replacement. Identification of cut-off values

Objective: To identify new cut-off values beyond which patients can be considered as satisfied or as responders through patient acceptable symptom state (PASS) and OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International) set of responder criteria in total joint replacement.

Methods: Secondary analysis of a 1-year prospective multicenter study of 861 patients, 510 with total knee replacement (TKR) and 351 with total hip prosthesis (THR). Pain and function data were collected by the reverse scoring option of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). PASS values were identified with the 25th centile estimation using an anchoring question about satisfaction with actual symptoms. OMERACT-OARSI set of responder criteria was based on a combination of absolute and relative change of pain, function and global patient's assessment. Receiver operating characteristic (ROC) analysis was used as a complementary approach.

Results: The values for PASS were about 80 and 69 for pain and function in THR, while these values were 80 and 68 when using OMERACT-OARSI criteria. Regarding TKR, PASS values were about 75 and 67 in pain and function with both criteria. ROC values were slightly lower in all cases. PASS and OMERACT-OARSI values varied moderately across tertiles of baseline severity.

Conclusion: With the provided data we can establish when a patient can be considered as satisfied/responder in joint replacement. The scores achieved at 1 year were very similar according to both criteria.