Physician Preferences and Variations in Prescription of Biologic Drugs for Rheumatoid Arthritis: A Register-Based Study of 4,010 Patients in Sweden.

OBJECTIVE: The prescription of biologic drugs for rheumatoid arthritis (RA) patients has varied considerably across different regions. Previous studies have shown physician preferences to be an important determinant in the decision to select biologic disease-modifying antirheumatic drugs (bDMARDs) rather than nonbiologic, synthetic DMARDs (sDMARDs) alone. The aim of this study was to test the hypothesis that physician preferences are an important determinant for prescribing bDMARDs for RA patients in Sweden.
METHODS: Using data from the Swedish Rheumatology Quality Register, we identified 4,010 RA patients who were not prescribed bDMARDs during the period 2008-2012, but who, on at least 1 occasion, had an sDMARD prescription and changed treatment for the first time to either a new sDMARD or a bDMARD. Physician preference for the use of bDMARDs was calculated using data on each physician's prescriptions during the study period. The relationship between prescription of a bDMARD and physician preference, controlling for patient characteristics, disease activity, and the physician's local context was evaluated using multivariate logistic regression.
RESULTS: When adjusting for patient characteristics, disease activity, and the physician's local context, physician preference was an important predictor for prescription of bDMARDs. Compared with patients of a physician in the lowest preference tertile, patients of physicians in the highest and middle tertiles had an odds ratio for receiving bDMARDs of 2.8 (95% confidence interval [95% CI] 2.13-3.68) and 1.28 (95% CI 1.05-1.57), respectively.
CONCLUSION: Physician preference is an important determinant for prescribing bDMARDs.