Long-term mortality rate in rheumatoid arthritis patients with disease onset in the 1980s

Abstract

Objective: To investigate the mortality rate and possible early predictive factors of mortality after 19–23 years in a cohort of patients with rheumatoid arthritis (RA) followed prospectively from disease onset.

Patients and methods: A community-based cohort of 183 patients (63% female) with RA and disease duration < 2 years was recruited 1985–1989. The patients were followed yearly from diagnosis until death or 31 December 2008. Mean age and mean duration of symptoms (range) at diagnosis were 52 (18–78) years and 11 (0–24) months, respectively. Death certificates were obtained from the Swedish Cause of Death Register and causes of death were coded by the International Classification of Diseases (ICD-10). Death rates of RA patients were compared to those of age- and sex-matched controls. Possible predictors of mortality were analysed using a Cox regression model.

Results: By 31 December 2008, 69 patients (37 women and 32 men) had died. The standardized mortality ratio (SMR) was 1.23 [95% confidence interval (CI) 0.97–1.55] and p < 0.09. Older age, male sex, smoking, and the presence of cardiovascular disease (CVD) at RA diagnosis were identified as early predictors of mortality. CVD was the most common cause of death (46%), followed by malignancies (29%) and infections (13%). RA was not stated as the direct cause of death in any patient and was mentioned among underlying causes in only 16/69 (23%) patients.

Conclusion: Mortality rate after 19–23 years of disease duration in this cohort of patients with disease onset in the 1980s was not significantly increased compared to age- and sex-matched controls. No RA disease-related factor predicted mortality.

Acknowledgements

This study was supported by grants from the Swedish Rheumatism Association, the Swedish Research Council, the Medical Faculty of the University of Lund, Alfred Österlund's Foundation, the Crafoord Foundation, Greta and Johan Kock's Foundation, the King Gustaf V Foundation, and Lund University Hospital.