To compare the performance of published classification/diagnostic criteria for polymyalgia rheumatica (PMR), including the new 2012 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, in a single-centre study.
We studied all consecutive patients with new-onset PMR seen in our centre over 6 years, whose diagnosis was confirmed during a prospective 12-month follow-up period. Subjects were classified by each of the seven different criteria. Sensitivity and specificity were compared. Control population consisted of all consecutive patients aged ≥50 years seen in a 4-year period in our early arthritis clinic who had a 12-month confirmation of a diagnosis of rheumatoid arthritis (RA) or other inflammatory articular diseases.
Data were collected from 136 cases and 149 controls, including 94 patients with RA. The most sensitive criteria were the new 2012 EULAR/ACR classification criteria (92.6%). Adding ultrasound (US) specificity increased from 81.5% to 91.3% in total cases and from 79.7% to 89.9% in RA. Bird criteria had a sensitivity of 89.2% but the lowest specificity (40.2% in total cases and 72.5% in RA). Jones and Nobunaga criteria were the most specific criteria (96.7% and 97.8% in total cases and 98.6% and 99.5% in RA) but the less sensitive (63.1% and 58.2%) ones. Overall, discriminatory ability, as reflected by the area under the receiver operating characteristic curve, was better for the 2012 US EULAR/ACR criteria (0.920 in total cases and 0.910 in RA).
The new EULAR/ACR criteria in new-onset PMR patients perform best in discriminating PMR from RA and other inflammatory articular diseases. Ultrasound further increases the specificity of the criteria.