Vascular disease as a cause of death in patients with severe disability due to osteoarthritis and rheumatoid arthritis

OBJECTIVES: The mechanism of the increased risk of cardiovascular disease in rheumatoid arthritis (RA) remains uncertain. We had the opportunity to compare the causes and ages of death in a population of osteoarthritis (OA) and RA patients who had had similar lower limb disability. METHODS: Death certificates were sought for a population of OA and RA patients who had had knee joint replacements performed by a single orthopaedic surgeon over a 10 year period with a minimum follow up period of 18 years. Primary cause of death was assigned by a blinded clinician and compared between the populations. Competing risk analysis was used to compare RA and OA populations for cardiovascular deaths. RESULTS: The total population was 607 (294 OA; 313 RA). 85% (249) of the OA and 79% (246) of the RA patients had deceased at the time of study in 2008. 85% of the death certificates were found. The RA patients were operated an average of 7.5 years younger and also died 7.5 years younger. The causes of death were similar in the two populations. The ages at death were consistently and similarly older for the OA group for all causes of death. There was a 9% increased risk of cardiovascular death in the RA group but this was not statistically different from the OA group. CONCLUSIONS: OA and RA patients, controlled for lower limb disability, have similar causes of death including cardiovascular disease. However, the RA patients died significantly younger. Cause of death is likely to be related to things that OA and RA share, such as disability and some treatments e.g. NSAIDs, whereas age at death relates to differences, such as age of onset and inflammation.