Causes of death in patients with rheumatoid arthritis: comparison with siblings and matched osteoarthritis controls

Survival of patients with rheumatoid arthritis (RA) is reduced when compared to the general population. We assessed differences in causes and age of death between patients with RA and their siblings. Comparisons were also made with a control group of subjects with lower limb osteoarthritis (OA).

A population of 257 patients with RA studied in 1991 was compared to 371 of their same-sex siblings and 485 patients with hip and knee OA who were also attending the department at this time. Death certificates were obtained and compared.

Among patients with RA, 54% (139/257) were deceased, compared to 28% (105/371) of the siblings and 32% (154/485) of OA patients (RA vs siblings or OA, p < 0.05). There were more deaths due to ischemic heart disease (IHD) in both the RA and OA groups compared to those expected; ratio observed/expected, 1.66 (95% CI 1.01, 2.79) and 1.96 (95% CI 1.21, 3.25), respectively, but not for siblings: observed/expected = 1.05 (95% CI 0.53, 2.08). There was a significant deficit in cancer related deaths in RA patients, observed/expected = 0.62 (95% CI 0.36, 1.03).

Significantly more patients with RA had died than in either of the comparator populations. RA and OA patients died more frequently of IHD than the siblings. The RA population had a 40% reduced rate of cancer related deaths than expected and compared to their siblings.