Characteristics of patients with polymyalgia rheumatica based on glucocorticoid dose in Japan: A cohort study using routinely collected health data.

Objectives: This study aimed to describe the characteristics, inflammatory markers as surrogates for disease activity, and treatment of patients with polymyalgia rheumatica (PMR) in Japan.

Methods: This cohort study analysed the data of 373 patients with PMR retrieved from an electronic medical records database in Japan. Patients were classified into quartiles, based on the daily glucocorticoid dose over the initial 90 days of treatment (Q1-Q4).

Results: The low glucocorticoid dose group (Q1) had more patients aged ≥90 years (11.7%), and a higher prevalence of comorbidities. At 52 weeks, glucocorticoid-free remission was achieved in 10% of patients, and higher C-reactive protein levels were observed during the follow-up period. In contrast, the high glucocorticoid dose group (Q4) exhibited a slower decline in C-reactive protein levels and more events of increased glucocorticoid dose compared to Q1-Q3. The introduction of methotrexate was low, with 4.3% to 7.3% of patients. The incidence of osteoporosis and diabetes was higher in patients <75 years, whereas the incidence of hypertension was higher in patients ≥75 years.

Conclusions: Patients refractory to high glucocorticoid doses were identified. Patients receiving inadequately low doses of glucocorticoids were older with more comorbidities. This study highlights the unmet medical needs for PMR.