Longterm therapy in polymyalgia rheumatica: effect of coexistent temporal arteritis.

Objective: To analyze the clinical course and duration of therapy in a series of 104 patients with polymyalgia rheumatica (PMR), identifying factors that influence prolonged steroid use and relapses.

Methods: Retrospective study of 104 cases of PMR diagnosed from 1985 to 1995. Patients were followed from time of diagnosis until either their death or December 31, 1995. To assess the effects of the coexistence of temporal arteritis (TA) on outcome in PMR, patients were grouped according to the absence or presence of arteritis. Kaplan-Meier survival analysis was performed to evaluate the duration of therapy, the incidence of prolonged remissions and relapses, and the average time to relapse. The log-rank test was used to test for significant differences between groups. Multivariate Cox proportional hazards regression models were used to identify variables associated with the occurrence of these events.

Results: Of 104 patients, 69 had pure PMR and 35 had both PMR and TA. Although some patients had limited disease requiring limited corticosteroid (CS) therapy (usually about 2 years), a significant number of patients had sustained disease requiring longterm treatment. Patients with simultaneous arteritis tended to have a longer duration of therapy, but no increased risk of relapse. By multivariate analysis, increasing age at diagnosis, female sex, higher baseline erythrocyte sedimentation rate, and lower daily CS dose were significant risk factors associated with long duration of therapy. No clinical feature predicted patients who were more likely to relapse.

Conclusion: Although there was great individual patient variation, we found that typically CS therapy lasted at least 2 years. Our findings allow the identification of patients who are particularly predisposed to need prolonged and higher dose cumulative steroid therapy and merit preventive strategies to decrease the incidence of steroid related adverse events.