First multi-center retrospective study assessed the compliance with and persistence of biological therapies in Bulgarian population with rheumatoid arthritis

Rheumatoid arthritis is an inflammatory joint disease that causes progressive joint damage, leading to severe disability. Early diagnosis, optimal therapy, and strict adherence to the prescribed medication are key factors that allow for the cessation of the disease progression and the preserving of the patient's quality of life. The objective of this study was to estimate the compliance to and persistence of biologic disease-modifying anti-rheumatic drugs (bDMARDs) among the Bulgarian population with RA. This retrospective observational cohort study included 179 patients, who were tracked over a 36-month period. During baseline and subsequent follow-up visits (at months 6, 12, 24, and 36), we monitored the disease activity, side effects, medication tolerability and effectiveness, compliance, and persistence to the prescribed biologic agent. The compliance with bDMARDs among Bulgarian patients with RA was 85.5% in the first year, 76.0% in the second year, and 63.7% in the third year. The Infliximab cohort showed the lowest compliance rate (50%), with the other subgroups bDMARDs having similar results (64-70%) during the period of observation. The median therapy duration across all patient cohorts is 61.9 months (IQR 55.7-67.6). Our study did not establish any significant impact of gender, age and disease duration, concomitant treatment with methotrexate, type of biologic agent and previous exposure to biological agents on the treatment adherence. The compliance with and persistence of the prescribed bDMARD among the Bulgarian population with RA is unsatisfactory. Therapy interruption and nonadherence to recommended therapy are associated with disease progression and patient disability. The consequences include not only financial burdens but also psychosocial and physical impacts.