Diagnosis of polymyalgia rheumatica in primary health care: favoring and confounding factors - a cohort study.

Objectives: To evaluate in a primary care setting the favoring and confounding factors for the diagnosis of polymyalgia rheumatica (PMR). Material and methods: Among 303 patients consecutively referred by their general practitioners (GPs) to our rheumatologic outpatient clinic, we identified three groups: group A - patients with confirmed diagnosis of PMR, group B - patients with unconfirmed diagnosis, group C - patients with unrecognized PMR. All the diagnostic confounding and favoring factors were discussed with GPs using an e-mail questionnaire. Participation in rheumatology training courses represented the final question. The collected data were statistically assessed in a blind way. In Fisher's exact test and ANOVA test, a p-value was significant if < 0.05. The study was carried out in compliance with the Helsinki Declaration and approved by the Ethics Committee of Mariano Lauro Hospital. Every patient signed an informed consent form at the time of the first visit. Results: All patients were Caucasian; 24.1% were male; mean age was 72.3 ±8.6 years (min. - 51, max. - 94). There were 41 patients in group A, 93 in group B and 169 in group C. The percentage of misdiagnoses was very high (87.1%): among 134 patients diagnosed with PMR by their GPs (group A + group B) confirmation was made in 41, and in 169 unrecognized PMR was found. Participation in training courses was very significant compared to the diagnostic accuracy (p < 0.0001 in χ2 test) and to the diagnosis timing (24.3 days ±12.5 vs. 42.9 ±15.5 with p-value < 0.05 in the ANOVA test). When the percentages were assessed according to participation, an inadequate evaluation of some clinical manifestations favored over-diagnosis among the trained GPs. Conclusions: The level of diagnostic accuracy for PMR must be improved in primary care. Participation in rheumatology training courses can be an important step.