Safety and Effectiveness of Biologic Disease-Modifying Antirheumatic Drugs in Older Patients with Rheumatoid Arthritis: A Prospective Cohort Study.

BACKGROUND AND OBJECTIVE: The number of older patients with rheumatoid arthritis is increasing, but data on drug effectiveness and safety in these patients are scarce. This study assessed the effectiveness and safety of biologic disease-modifying antirheumatic drugs in older patients with rheumatoid arthritis. METHODS: This prospective cohort study was based on data recorded in the Rheumatic Diseases Portuguese Register (Reuma.pt). Treatment persistence, European League Against Rheumatism response at 6 and 12 months, and adverse events were compared between adult (age < 65 years), old (age 65-74 years), and very old (age ≥ 75 years) patients. RESULTS: In total, 2401 patients were included, of which 379 were old and 83 were very old. Older patients had higher disease activity at baseline (Disease Activity Score 28: 5.5 in adults, 5.7 in old patients, and 6 in very old patients; p = 0.02) and more comorbidities, with patients aged 65-74 years beginning biologic disease-modifying antirheumatic drugs later in the course of rheumatoid arthritis. Treatment persistence was similar in the three patient groups (p = 0.07). The European League Against Rheumatism response rates were comparable in the three groups at 6 months (81.6% of adults, 75.2% of old patients, and 81.8% of very old patients; p = 0.19), and inferior in old patients at 12 months. The proportion of patients who experienced adverse events was also similar in the three groups (21% of adults, 22.5% of old patients, and 22.9% of very old patients; p = 0.76), but the rate of serious adverse events was higher in old patients (1.94/100 patient-years) and very old patients (4.29/100 patient-years) compared with 1.03/100 patient-years in adult patients with rheumatoid arthritis (p < 0.05). CONCLUSIONS: Adults, old patients, and very old patients with rheumatoid arthritis benefit similarly from biologic disease-modifying antirheumatic drug treatments, although older patients have more active disease at baseline and more comorbidities. However, it is necessary to consider the risk of serious adverse events in older patients when prescribing a biologic.