(149) Characteristics Associated with Long-Term Glucocorticoid Use in Patients with New Onset Polymyalgia Rheumatica

Background: Polymyalgia Rheumatica (PMR), an inflammatory condition in ≥50-year-olds, is managed with glucocorticoid (GC) therapy recommended for 36–48 weeks without a flare or 40–52 weeks with a single flare. However, 77%, 51%, and 25% remain on GC at 1, 2, and 5 years. Extended GC use increases toxicity, especially in the elderly. Early recognition of patients needing >1-year GC treatment can identify those at risk of toxicity and may benefit from GC-sparing therapy.

Objectives: To identify characteristics at 6 months in new onset PMR patients associated with GC use beyond 1 year.

Methods: This was an analysis of a new onset PMR cohort from Medicare claims (10/01/2016–12/31/2020). Patients included were aged ≥50 years, had no history of PMR/giant cell arteritis and ≥1 inpatient/≥2 outpatient claims ≥30 days to < 365 days apart, started GC 7.5–25 mg/day ≤30 days after 1st inpatient or from 1st outpatient to ≤30 days after 2nd outpatient code, had GC dose ≥200 mg in 1st ≤30 days and ≥4 months use and enrollment ≥1 year before diagnosis. Patients with other systemic rheumatic disease, malignancy treatment, multiple sclerosis, organ transplant, or conventional synthetic immunomodulatory (csIM) drugs or IL-6 receptor inhibitors ≤1 year prior to 1st inpatient or 2nd outpatient claim to 6 months after starting GC were excluded (GC cohort). The primary outcome was comparison of characteristics at 6 months in patients who were on GC vs. off GC at 1 year. An additional analysis assessed patients who met criteria but had a csIM ≤6 months from starting GC (csIM cohort). Comorbidities were defined with diagnosis, procedure, or drug codes and frailty by a validated claims-based frailty index.

Results: 4,748 patients were included in the GC cohort and 318 in the csIM cohort. Methotrexate (MTX) was the most common csIM [200/318 (62.9%)]. Of patients in the GC and csIM cohort, 3,038 (64.0%) and 183 (57.5%) were on GC at 1 year. In both cohorts, more patients on GC vs. off GC at 1 year were on GC dose ≥5 mg at 6 months. Patients on GC vs. off GC at 1 year had higher cumulative GC use at 6 months in both cohorts.
In the GC cohort, demographic characteristics and comorbidities or frailty at 6 months, were not associated with GC use at 1 year while in the csIM cohort, age, year GC was initiated, initial GC dose, and glaucoma were associated with GC use at 1 year. A sensitivity analysis including patients who initiated MTX within 6 months found 55.5% (111/200) of patients were on GC at 1 year and MTX use was associated with GC use at 1 year; fewer patients on GC vs. off GC at 1 year had received MTX within 6 months 111/3149 (3.5%) vs 89/1799 (4.9%).

Conclusions: Over half of PMR patients remained on GC after 1 year. GC dose at 6 months may help identify patients who may benefit from GC sparing therapy.