The polymyalgia rheumatica activity score in daily use: proposal for a definition of remission

OBJECTIVE: To confirm the reliability and applicability of the Polymyalgia Rheumatica Disease Activity Score (PMR-AS), and to establish a threshold for remission. METHODS: First, 78 patients with PMR (50 women/28 men, mean age 65.97 years) were enrolled in a cross-sectional evaluation. The PMR-AS, patient's satisfaction with disease status (PATSAT; range 1-5), erythrocyte sedimentation rate (ESR; first hour), and a visual analog scale of patients' general health assessment (VAS patient global; range 0-100) were recorded. Subsequently, another 39 PMR patients (24 women/15 men, mean age 68.12 years) were followed longitudinally. Relationships between the PMR-AS, PATSAT, ESR, and VAS patient global were analyzed by the Kruskal-Wallis test, Spearman's rank correlation, and kappa statistics. PMR-AS values in patients with a PATSAT score of 1 and a VAS patient global <10 formed the basis to establish a remission threshold. RESULTS: PMR-AS values were significantly related to PATSAT (P < 0.001), VAS patient global (P < 0.001), and ESR (P < 0.01). PATSAT and VAS patient global were reasonably different (kappa = 0.226). The median PMR-AS score in patients with PATSAT score 1 and VAS patient global <10 was 0.7 (range 0-3.3), and the respective 75th percentile was 1.3. To enhance applicability, a range from 0 to 1.5 was proposed to define remission in PMR. The median ESR in these patients was 10 mm/hour (range 3-28), indicating external validity. CONCLUSION: We demonstrated the reliability, validity, and applicability of the PMR-AS in daily routine. Moreover, we proposed a remission threshold (0-1.5) founded on patient-dependent parameters.