Comparison of Biologic Discontinuation in Patients With Elderly-Onset Versus Younger-Onset Rheumatoid Arthritis

Objective: The objective of this study is to compare biologic drug discontinuation rates for older- versus younger-onset rheumatoid arthritis (YORA) because this is a key outcome measure that could impact prescribing practices. Methods: We performed a retrospective medical record review of all patients who fulfilled the 1987 American College of Rheumatology (ACR) criteria for adult-onset rheumatoid arthritis (RA) in 1999-2013 among residents of a geographically defined area, with follow-up until death, migration, or July 1, 2017. Discontinuation rates were estimated using cumulative incidence adjusted for the competing risk of death. Results: A total of 240 cases of elderly-onset rheumatoid arthritis (EORA) and 366 cases of YORA were identified (65% and 73% female, respectively; P = 0.025). Cumulative incidence of biologic initiation was lower among the EORA cohort compared with the YORA cohort (18% vs 33%, respectively, at 10 years after RA incidence; P < 0.001). Among those treated with a biologic, years from RA diagnosis to first biologic treatment was not significantly different between the two groups (P = 0.62). Drug survival of first biologic was 64% at 1 year (95% confidence interval [CI]: 45%-77%) and 53% at 2 years (95% CI: 33%-66%) for EORA, compared with 61% at 1 year (95% CI: 50%-69%) and 45% at 2 years (95% CI: 34%-53%) for YORA (P = 0.75). Concurrent glucocorticoid use at initiation of first biologic was statistically and significantly associated with a lower risk of discontinuation in EORA (hazard ratio 0.21; 95% CI: 0.08-0.53) but not in YORA (interaction P = 0.04). Conclusion: Drug survival rates of biologic medications did not differ significantly between patients with EORA and YORA.