Trajectory analysis of glucocorticoid treatment highlights issues in the current tapering strategy for polymyalgia rheumatica.

Objectives: To identify glucocorticoid (GC) treatment patterns in patients with polymyalgia rheumatica (PMR) and explore patient profiles that may benefit from GC-sparing interventions.

Methods: This descriptive study was conducted using an electronic medical record database in Japan. We identified patients with PMR aged ≥50 years who were initiated 5-<30 mg/day of GCs with increased inflammatory markers. Group-based trajectory modelling (GBTM) was used to characterise GC treatment patterns over 52 weeks. We analysed clinical characteristics, including changes in GC doses, longitudinal C-reactive protein levels, immunosuppressant use and GC-related toxicities.

Results: Among 452 eligible patients with PMR, four treatment trajectories were identified: rapidly-declining (19.0%), low-dose (36.9%), intermediate-dose (32.5%) and high-dose (11.5%). The rapidly declining and low-dose groups had more patients aged ≥80 years and with comorbidities. The median doses at week 52 in the low-dose, intermediate-dose and high-dose groups were 3.0, 4.0 and 7.5 mg/day, respectively. These groups had higher cumulative doses and greater GC-related toxicities compared with the rapidly declining group, which was reduced to 0 mg/day by week 8. The cumulative incidence of immunosuppressant use at week 52 was 6.1%-10.5%, even in the high-dose group.

Conclusions: GBTM analysis indicates that many patients who do not discontinue GC use within 1 year are exposed to high cumulative GC doses, which are associated with an elevated risk of GC-related toxicities. Our findings highlight the need to reconsider treatment strategies for patients with PMR, including the use of GC-sparing agents.