Patterns of glucocorticoid prescribing and provider-level variation in a commercially insured incident rheumatoid arthritis population: A retrospective cohort study.

OBJECTIVE: Glucocorticoids are common in RA management despite an unfavorable, exposure-dependent risk profile impacted by patient and provider-level factors. Existing work describing glucocorticoid use in RA is not generalizable and does not adequately examine provider factors. We aim to describe how providers prescribe glucocorticoids to commercially insured, newly diagnosed RA patients in the United States.
METHODS: This was a retrospective cohort study which used the national Optum© administrative database. We identified 9221 adults ages 18-65 with RA diagnosed 2010-2014. We assessed glucocorticoid dispensing 3 months pre-diagnosis through 12months post-diagnosis ("study period"), cumulatively stratified by calendar quarter and prescriber specialty (rheumatologist, primary care, other). We examined prescribing variation among individual rheumatologists by dividing quarterly distribution of per-patient dose and days' supply into quartiles.
RESULTS: 6717 (72.8%) patients filled ≥1 glucocorticoid prescription during the study period. 2890 (31.3%) patients received ≥3 months' supply, with median (IQR) daily dose 10 (6.6) mg/day and days' supply 189 (143) days. 52.6% of patients received glucocorticoids 1-3 months post-diagnosis; 29.2% received glucocorticoids 10-12 months post-diagnosis. Among glucocorticoid users post-diagnosis, quarterly median daily dose and days' supply were consistently ≥10 mg/day and ≥30 days, respectively. Rheumatologists prescribed most glucocorticoids, with median per-quarter daily dose and days' supply 10 mg/day and 43-60 days. Individual rheumatologists' prescribing varied widely across all quarters.
CONCLUSION: Among commercially insured incident RA patients, receipt of ≥10 mg/day prednisone equivalent for months is common, typically prescribed by rheumatologists, and persists a year post-diagnosis in 29.2% of patients. Glucocorticoid prescribing varies widely across rheumatologists. Further work is warranted to identify provider factors explaining variation in glucocorticoid prescribing, and assess how these affect health outcomes.