Minimum clinically important improvement and patient acceptable symptom state in pain and function in rheumatoid arthritis, ankylosing spondylitis, chronic back pain, hand osteoarthritis, and hip and knee osteoarthritis: Results from a prospective multinational study

Abstract

Objective: To estimate the minimum clinically important improvement (MCII) and patient acceptable symptom state (PASS) values for 4 generic outcomes in 5 rheumatic diseases and 7 countries. Methods: We conducted a multinational (Australia, France, Italy, Lebanon, Morocco, Spain, and The Netherlands) 4‐week cohort study involving 1,532 patients who were prescribed nonsteroidal antiinflammatory drugs for ankylosing spondylitis, chronic back pain, hand osteoarthritis, hip and/or knee osteoarthritis, or rheumatoid arthritis. The MCII and PASS values were estimated with the 75th percentile approach for 4 generic outcomes: pain, patient global assessment, functional disability, and physician global assessment, all normalized to a 0–100 score. Results: For the whole sample, the estimated MCII values for absolute change at 4 weeks were −17 (95% confidence interval [95% CI] −18, −15) for pain; −15 (95% CI −16, −14) for patient global assessment; −12 (95% CI −13, −11) for functional disability assessment; and −14 (95% CI −15, −14) for physician global assessment. For the whole sample, the estimated PASS values were 42 (95% CI 40, 44) for pain; 43 (95% CI 41, 45) for patient global assessment; 43 (95% CI 41, 44) for functional disability assessment; and 39 (95% CI 37, 40) for physician global assessment. Estimates were consistent across diseases and countries (for subgroups ≥20 patients). Conclusion: This work allows for promoting the use of values of MCII (15 of 100 for absolute improvement, 20% for relative improvement) and PASS (40 of 100) in reporting the results of trials of any of the 5 involved rheumatic diseases with pain, patient global assessment, physical function, or physician global assessment used as outcome criteria.