Background Polymyalgia rheumatica (PMR) is a common rheumatic disorder in the elderly population. General Internal Medicine doctors often encounter these patients. However, the gold standard for the diagnosis of PMR is nonexistent. Recently, new classification criteria for PMR have been presented by ACR and EULAR. Exactly using the ultrasound to diagnose PMR, it is well known that specificity will be improved. However, all general physicians do not have assured techniques of joint power Doppler ultrasonography. This time, we compared the diagnostic accuracy between EULAR/ACR classification (scoring algorithm without Ultrasound -3 required criteria) and Bird criteria, Chuang criteria and Kyle criteria for PMR.
Objectives To investigate the diagnostic accuracy including sensitivity and specificity of each criterion. The objectives were 48 cases of PMR that had been started PSL therapy with the 3 positive factors or more on Bird criteria during June 2008 to May 2013.
Methods Forty-eight cases were evaluated retrospectively and coefficient of agreement. In addition, discriminant analysis was performed on 4 criteria.
Results In total 48 patients, 30 patients (62.5%) were female. Average age was 75.4±8.5 years old (48-89yo). As same as EULAR/ACR study design, we decided final diagnosis of PMR after 26 weeks starting steroid treatment. Finally, PMR cases are 41 and Non-PMR cases are 7cases (Prevalence: 85.4%). All 48 cases are matched for Bird criteria. Four cases had not examined ACPA and RF at initial diagnosis, EULAR/ACR classification was adapted 44 cases (Prevalence 84.1%).
Table 1 shows the comparison of the diagnostic accuracy and coefficient of agreement of 3 criteria.
Table 2 shows the results of discriminant analysis.
Conclusions EULAR/ACR provisional classification had better performance than the other PMR criterion with a statistically significant. This study did not include a lot of control case, high prevalence prevented from having a high matching coefficient κ(kappa) value on EULAR/ACR classification. From the discriminant analysis, EULAR/ACR classification had a high discriminant probability with 83%. At the present moment, EULAR/ACR classification is the most reliable criteria for PMR.
Dasgupta B, Cimmino MA, Maradit-Kremers H, et al. 2012 provisional classification criteria for polymyalgia rheumatica: a European League Against Rheumatism/American College of Rheumatology collaborative initiative. Ann Rheum Dis. 2012 Apr;71(4):484-92.
Bird HA, Esselinckx W, Dixon AS, et al. An evaluation of criteria for polymyalgia rheumatica. Ann Rheum Dis. 1979 Oct;38(5):434-9.
Disclosure of Interest None declared