Long-term Outcomes Based on the Sex of the Rheumatologist in a Prospective Cohort of Rheumatoid Arthritis Patients

Objective: To explore the influence of the physician's sex on long-term outcomes in patients with rheumatoid arthritis (RA) undergoing targeted therapy. Methods: A prospective, single-center cohort study of adult RA patients treated with biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) was conducted between 2014 and 2022. The physician’s sex was the main exposure. The primary outcome was disease activity score in 28 joints (DAS28), and the secondary outcomes were DAS28 subcomponents and glucocorticoid use. The association between the physician's sex and outcomes was assessed by generalized estimating equations. Covariates were selected through regularization techniques. Results: We included 1151 patients (81% female) with a mean age of 57 years, a mean disease duration of 14 years, and a median observation of 4 years. At the time of inclusion, 68% of the patients had moderate-high DAS28. Management by female physicians yielded significantly lower mean DAS28 (2.80 [95% CI, 2.65 to 2.97] vs 3.00 [95% CI, 2.87 to 3.19]; P=.004) and a higher likelihood of DAS28 remission (adjusted odds ratio, 1.84 [95% CI, 1.16 to 2.17]; P<.0001) compared with male physicians. Secondary outcome analyses also found lower C-reactive protein level (2.5 vs 3.5 mg/L; P<.0001) and swollen joint count in 28 joints (0.9 vs 1.4; P<.0001) and no significant differences in glucocorticoid use. Sensitivity analyses found that the effect of the physician’s sex was mostly directed at male patients. Conclusion: The sex of the physician can significantly influence disease control in patients with RA, with female rheumatologists achieving better outcomes in terms of disease activity and remission.