Estimation of Minimally Important Differences and Patient Acceptable Symptom State Scores for the Patient-Reported Outcomes Measurement Information System Pain Interference Short Form in Rheumatoid Arthritis.

The best estimate of a group-level MID was approximately 2 points, similar to MIDs suggested in other conditions. The PASS value for the entire group was almost an SD better than the population mean. Results should enhance use of PROMIS PI in RA by facilitating interpretation of scores and changes.