Classification Criteria Help ID Polymyalgia Rheumatica
Scoring algorithm discriminates PMR from shoulder conditions, rheumatoid arthritis
WEDNESDAY, March 7 (HealthDay News) -- Provisional classification criteria have been established to discriminate polymyalgia rheumatica (PMR) from conditions which mimic PMR, according to a study published in the April issue of Arthritis & Rheumatism.
To develop European League Against Rheumatism/American College of Rheumatology classification criteria for PMR, Bhaskar Dasgupta, M.D., of Southend University Hospital in Westcliff-on-Sea, U.K., and associates evaluated candidate criteria in a six-month prospective cohort study of 125 patients with new-onset disease and 169 controls with conditions mimicking PMR.
The researchers developed a scoring algorithm on the basis of four factors: more than 45 minutes of morning stiffness; hip pain/limited range of motion; absence of rheumatoid factor and/or anti-citrullinated protein antibody; and absence of peripheral joint pain. A score of 4 or more discriminated PMR cases from controls with 68 percent sensitivity and 78 percent specificity. Shoulder conditions could be discriminated with greater specificity (88 percent), while rheumatoid arthritis was discriminated with lower specificity (65 percent). A score of 5 or more increased sensitivity to 66 percent and specificity to 81 percent, on addition of ultrasound.
"According to these provisional classification criteria, patients ≥50 years old presenting with bilateral shoulder pain, not better explained by an alternative pathology, can be classified as having PMR in the presence of morning stiffness >45 minutes, elevated C-reactive protein and/or erythrocyte sedimentation rate, and new hip pain," the authors write.
Several authors disclosed financial ties to the pharmaceutical industry.