PHILADELPHIA — Rheumatoid arthritis became less deadly since the mid-1990s compared with the preceding 4 decades, based on population-based data from about 600 patients.
During 1995–2007, the 5-year mortality estimate in 463 patients newly diagnosed with rheumatoid arthritis (RA) was 7%, compared with a 13% rate among 147 patients who had their initial diagnosis during 1985–1994, Dr. Elena Myasoedova said at the annual meeting of the American College of Rheumatology.
In an analysis that adjusted for age and gender, this represented a statistically significant, 33% drop in the mortality rate among new RA patients compared with the prior decade, said Dr. Myasoedova, a rheumatologist at the Mayo Clinic in Rochester, Minn.
In contrast, mortality among the RA patients was “essentially unchanged” during each of the 3 decades before 1995, based on additional data from a Rochester, Minn., cohort. Participants were aged 18 years or older and were classified as having RA during 1995–2007, categorized on the basis of 1987 diagnostic criteria of the American College of Rheumatology. The patients came from Olmsted County, Minn., and enrolled in the Rochester Epidemiology Project.
A comparison of the 1985–1994 and 1995–2007 groups showed that more recently diagnosed patients were less likely to have ever smoked, with a 50% prevalence compared with a 60% rate in the prior decade. The most recent patients had a higher prevalence of obesity, 47% compared with a 22% rate in the earlier decade. The 1995–2007 group also had lower average erythrocyte sedimentation rates, 30 mm/hour compared with 35 mm/hour in the prior decade. But the most current patients were more likely to have erosions or destructive joint changes, with a 29% prevalence compared with 21% in 1985–1994.
Additional analyses of the 1985–1994 and 1995–2007 groups showed that RA survival was better more recently regardless of gender or whether patients were positive or negative for rheumatoid factor.
It's unclear what led to improved survival. Possible explanations include a trend toward milder disease, as well as improved RA control using newer treatments and an approach that favors aggressive treatments earlier in the course of RA, Dr. Myasoedova said.
A second report she presented in a poster at the meeting showed that patients diagnosed with RA during 1995–2007 had half the rate of second extra-articular manifestations compared with the 1985–1994 patients. This finding is relevant to survival because extra-articular manifestations are significant predictors of mortality.
The 1995–2007 group of 463 patients had 159 incident extra-articular manifestations (34%), but only 37 second manifestations (8%), Dr. Myasoedova reported in her poster.
She and her associates again speculated in their poster that improved RA management and possibly milder RA disease may have led to the decline in second extra-articular manifestations, which in turn may have cut RA mortality. Dr. Myasoedova reported that she had no disclosures.
Possible explanations include a trend toward milder disease and newer, aggressive treatments.
Source DR. MYASOEDOVA
