Glucocorticoids are recommended for short-term use in rheumatoid arthritis (RA), but many patients continue receiving long-term therapy. We evaluated the variability in glucocorticoid prescribing across rheumatologists to inform interventions to limit long-term glucocorticoid use to the lowest dose necessary.
Two cohorts were created using Medicare data from 2006 to 2015. Using cohort 1 (RA patients receiving disease-modifying antirheumatic drugs [DMARDs]), we calculated each rheumatologist's "provider preference" for glucocorticoids (frequency of use compared to other providers), using the ratio of observed to expected number of patients receiving glucocorticoids to account for case mix. In cohort 2 (RA patients receiving stable DMARD therapy), we evaluated whether provider preference for glucocorticoids could independently predict use of ≥5 mg/day of glucocorticoids 6-9 months after initiation of DMARD therapy.
Using cohort 1 (1,272,644 yearly observations; 385,597 patients), we calculated provider preference among 6,875 rheumatologists (28,936 yearly observations). Provider preference was highly variable, with physicians at the lowest and upper quartiles prescribing glucocorticoids 33% less often to 31% more often (25th and 75th percentiles, respectively) than expected. In cohort 2 (155,539 patients receiving stable DMARD therapy), provider preference was strongly associated with glucocorticoid use ≥5 mg/day at 6-9 months, with a predicted probability of use of 22% (95% confidence interval [95% CI] 21.7-22.7) versus 11% (95% CI 10.2-10.9) for a patient seeing a provider in the highest versus lowest quintile of preference.
Glucocorticoid prescribing for RA varies greatly among rheumatologists, and provider preference is one of the strongest predictors of a patient's long-term glucocorticoid use. These findings raise quality of care concerns and highlight the need for stronger evidence to guide RA treatment.