October 29, 2007 — Patients with rheumatoid arthritis (RA) continue to die at a faster rate than the general population, according to the results of a study reported in the November 2007 issue of Arthritis and Rheumatism. This widening mortality gap highlights the crucial need to identify treatments that could improve survival in patients with this disease.
"We found no evidence indicating that RA subjects experienced improvements in survival over the last 4 – 5 decades," senior author Sherine E. Gabriel, MD, MSc, from the Mayo Clinic in Rochester, Minnesota, says in a news release. "In fact, RA subjects did not even experience the same improvements in survival as their peers without arthritis, resulting in a worsening of the relative mortality in more recent years, and a widening of the mortality gap between RA subjects and the general population throughout time."
During the past few decades of significantly increased survival in the overall population, RA patients have also benefited from earlier diagnosis, breakthrough drugs, and more aggressive treatment regimens. However, whether these improvements in management are associated with improved survival was not well defined.
Using the medical record database of all residents of Olmsted County, Minnesota, the investigators identified 822 subjects with RA by American College of Rheumatology criteria, aged 18 years or older. This included all residents of Rochester first diagnosed with RA between January 1, 1955, and January 1, 1995, as well as all residents of Olmsted County diagnosed with RA between January 1, 1995, and January 1, 2000.
Mean age at RA incidence was 57.6 years; 71.5% of the patients were women. Follow-up through medical record review continued until death or January 1, 2007. During follow-up of median duration 11.7 years, 445 patients with RA died.
Using Cox regression models adjusting for age and sex, the investigators compared the survival rates of patients diagnosed with RA from 1955 to 1964, 1965 to 1974, 1975 to 1984, 1985 to 1994, and 1995 to 2000. During these 5 time periods, survival rates for RA patients did not change significantly, indicating no significant improvements in longevity.
These results were confirmed using person-year methods to calculate and compare mortality rates for RA patients vs those in the general population. Expected deaths for people in the general Minnesota white population of similar age and sex as the RA patients were determined from the National Center for Health Statistics life tables.
Although the expected mortality rate in the general population dropped dramatically for both men and women between 1965 and 2005, the mortality rates for female and male RA subjects were relatively constant at 2.4 and 2.5 per 100 person-years, respectively, during the same time period. For women in the Minnesota general population, mortality decreased from 1.0 per 100 person-years in 1965 to 0.2 per 100 person-years in 2000, whereas for men, mortality decreased from 1.2 per 100 person-years in 1965 to 0.3 per 100 person-years in 2000.
"Although the reasons for the widening mortality gap are unclear, cardiovascular deaths constitute at least half of the deaths in subjects with RA, and it is possible that the cardiovascular interventions that improved life expectancy in the general population may not have had the same beneficial effects in persons with RA," Dr. Gabriel said.
Study limitations include sample limited almost exclusively to white individuals in 1 geographic area, the possibility that individuals with RA who did not present for medical care were not included, and the inability to extrapolate the findings to patients diagnosed with RA after 2000, who may have been treated more aggressively.
The authors urgently recommend research that will elucidate the reasons behind this striking mortality discrepancy and that will lead to solutions improving survival in patients with RA.
The National Institutes of Health supported this study.
Arthritis Rheum. 2007;56:3583–3587.
Medscape Medical News © 2007 Medscape
Cite this: Laurie Barclay. Mortality Gap Widens for Patients With Rheumatoid Arthritis - Medscape - Oct 29, 2007.