"Feeling better" or "feeling well" in usual care of hip and knee osteoarthritis pain: determination of cutoff points for patient acceptable symptom state (PASS) and minimal clinically important improvement (MCII) at rest and on movement in a national multicenter cohort study of 2414 patients with painful osteoarthritis

Abstract

Patient-reported outcome measures are being developed for more relevant assessments of pain management. The patient acceptable symptom state (PASS) ("feeling well") and the minimal clinically important improvement (MCII) ("feeling better") have been determined in clinical trials, but not in daily pain management. We carried out a national multicenter cohort study of patients over the age of 50years with painful knee osteoarthritis (KOA) or hip osteoarthritis (HOA) who had visited their general practitioner and required treatment for more than 7days. Overall, 2414 patients (50.2% men, mean age 67.3years, body mass index 27.9kg/m(2), 33.5% with HOA) were enrolled by 1116 general practitioners. After 7days of treatment, PASS was estimated on a numerical rating scale as 4 at rest and 5 on movement, for both HOA and KOA, above the PASS threshold in clinical trials. In KOA, PASS was more frequently reached in men and younger people with less pain at rest and on movement, and in patients specifically seeking an improvement during sport activities. In HOA, PASS was most frequently reached in patients with low levels of pain at risk and in nonobese patients. MCII was -1 numerical rating scale point after 7days of usual treatment. This improvement is smaller than that recorded in randomized controlled trials, and was the same for both sites, both at rest and on movement. In conclusion, patient-reported outcome values in daily practice differ from those in clinical trials, and their determinant factors may depend on the site of osteoarthritis. Assessments of the treatment of painful osteoarthritis should be adapted to the characteristics and daily life of the patient, to personalize patient management.