Is there a sex bias in prescribing anti-tumour necrosis factor medications to patients with rheumatoid arthritis? A nation-wide cross-sectional study

Objectives To determine whether men and women with rheumatoid arthritis are prescribed anti-tumour necrosis factor (anti-TNF) treatment at different levels of disease activity. Methods Data from the Swedish national biologics registry ARTIS were used to analyse characteristics of patients' disease at the start of the first anti-TNF treatment. Means for men and women were compared using t-tests, and non-normally distributed covariates were compared using the Wilcoxon rank-sum test. Linear regression models, adjusted for age and calendar year, were used to investigate the association between sex and each disease activity measurement. Results Women were younger and had longer disease duration at treatment start than men. Tender joint count, erythrocyte sedimentation rate, patient's global assessment, patient-reported pain and health assessment questionnaire scores were significantly higher in women, whereas men had a higher level of C-reactive protein (p < 0.05 for all comparisons). Swollen joint count and physician's global assessment did not differ by sex. Conclusions For women with rheumatoid arthritis, treatment with anti-TNF therapy was initiated at a higher level of subjective disease activity than for men, but at the same level of physician-reported disease activity. These data imply that patients' subjectively experienced disease activity may be discounted in the treatment decision.