Decreasing mortality in patients with rheumatoid arthritis: results from a large population based cohort in Sweden, 1964-95

Abstract

Objective: To assess changes in mortality in patients with rheumatoid arthritis (RA) from 1964 to 1995.

Methods: A population based cohort of 46,917 patients with RA was identified from 1964 to 1994, using the Swedish Hospital Discharge Register, and followed until 1995 through linkage to the Cause of Death Register. Mortality was separately analyzed in each inclusion period (1964-75, 1975-84, 1985-94). The relative risk of death was estimated as standardized mortality ratio (SMR) using the Swedish population as a reference

Results: All-cause mortality was increased twice the expected (SMR = 2.03, 95% CI 2.00, 2.05). Coronary artery disease was the major cause of death and mortality was increased by 80% (SMR = 1.79, 95% CI 1.75, 1.83). Females with RA aged 20-39 at first discharge had a more than 5-fold increased risk of coronary death (SMR = 5.48, 95% CI 3.45-5.71). From 1975 patients with RA had decreasing all-cause mortality. This decline was most pronounced in patients aged 40-59 at first discharge, where SMR was 2.68 (95% CI 2.45, 2.92) from 1964 to 1974 compared to SMR 1.63 (95% CI 1.37, 1.92) from 1985 to 1994.

Conclusion: The elevated mortality rates in RA patients compared to the general population have decreased during the last 20 years, possibly due to an increased access to specialized rheumatology care. An excess risk for death in coronary artery disease was, however, present in RA patients, especially patients with early onset of disease.