Mortality estimates and excess mortality in rheumatoid arthritis

Area of Science:

• Rheumatology
• Epidemiology
• Public Health

Background:

• Rheumatoid arthritis (RA) is a chronic autoimmune disease affecting joints and potentially other organs.
• Long-term survival data in RA patients are crucial for understanding disease impact and improving patient care.
• Previous studies suggest increased mortality in RA, but long-term trends require further investigation.

Purpose of the Study:

• To determine the 20-year survival rates of patients with rheumatoid arthritis (RA) in Australia.
• To compare the mortality rates of RA patients with the general Australian population.
• To identify causes of death contributing to the mortality gap in RA patients.

Main Methods:

• Utilized data from the Australian Rheumatology Association Database (ARAD) for RA patients diagnosed from 1995 onwards.
• Linked patient data with the Australian National Death Index for mortality information.
• Employed standardized mortality ratio (SMR) and relative survival models, calculating restricted mean survival time (RMST) and cause-specific SMRs (CS-SMRs).

Main Results:

• A cohort of 1895 RA patients was analyzed, with 204 deaths over 20 years.
• No increased mortality was observed in the first 10 years, but by 20 years, the SMR was 1.49.
• Respiratory conditions, specifically pneumonia and interstitial lung disease, were major causes of death, while coronary heart disease and neoplasms showed no significant increase.

Conclusions:

• Mortality risk in RA patients increases over time, with a moderate elevation observed at 20-year follow-up.
• Respiratory diseases appear to be a more significant contributor to the excess mortality in RA than cardiovascular diseases.
• These findings highlight the importance of monitoring and managing respiratory complications in long-term RA care.