Temporal trends in mortality in patients with rheumatoid arthritis: a Danish population-based matched cohort study

Abstract

Abstract Objectives To investigate the 5-year all-cause mortality in patients with RA compared with the general population. Methods This was a nationwide population-based matched cohort study. RA patients diagnosed between 1996 and the end of 2015 were identified using administrative heath registries and followed until the end of 2020 allowing 5 years of follow-up. Patients with incident RA were matched 1:5 on year of birth and sex with non-RA individuals from the Danish general population. Time-to-event analyses were performed using the pseudo-observation approach. Results Compared with matched controls in 1996–2000, the risk difference for RA patients ranged from 3.5% (95% CI 2.7%, 4.4%) in 1996–2000 to –1.6% (95% CI –2.3%, –1.0%) in 2011–15, and the relative risk from 1.3 (95% CI 1.2, 1.4) in 1996–2000 to 0.9 (95% CI 0.8, 0.9) in 2011–15. The age-adjusted 5-year cumulative incidence proportion of death for a 60-year-old RA patient decreased from 8.1% (95% CI 7.3%, 8.9%) when diagnosed in 1996–2000 to 2.9% (95% CI 2.3%, 3.5%) in 2011–15, and for matched controls from 4.6% (95% CI 4.2%, 4.9%) to 2.1% (95% CI 1.9%, 2.4%). Excess mortality persisted in women with RA throughout the study period, while the mortality risk for men with RA in 2011–15 was similar to their matched controls. Conclusions Enhanced improvement in mortality was found in RA patients compared with matched controls, but for sex-specific differences excess mortality was only persistent in women with RA.