Population-based mortality outcome of rheumatoid arthritis in females

Rheumatoid arthritis (RA) is a systemic disease whose morbidity exceeds its mortality. This abstract quantifies the mortality of RA in a general population over a 30-year period in females. The generic, across the spectrum of disease, mortality ratio is 136%; the excess death rate is 12. The mortality impact on males is minimal; the source publication noted a mortality ratio of 107%. Many selected cases of RA can be underwritten very favorably. PURPOSE: To quantify the excess mortality in females diagnosed with rheumatoid arthritis (RA) between 1955 to 1985. SUBJECTS AND METHODS: Medical records of all residents age 35 and over of Rochester, Minnesota, who met the American College of Rheumatology 1987 diagnostic criteria for RA were reviewed. Based on the comprehensive statistical base for residents in Rochester, virtually complete ascertainment of all clinically recognized cases of RA were identified. An incidence cohort identifying the same residents with new cases of RA occurring between January 1, 1955, and January 1, 1985, was created. Three, 10-year prevalence cohorts were assembled as of July 1, 1965, 1975 and 1985. Patients in each cohort were followed longitudinally until death or migration from Rochester. Data of disease characteristics, course, co-morbidity and death were collected. During the follow-up period, 6.9% moved out of the county, and 5.1% moved into the county after the diagnosis of RA had been made elsewhere. Expected survival was based on age and sex adjusted survival from the same community in the same time period. Mortality was described using the Kaplan-Meier product-limit method. Cox proportional hazards modeling was used to examine the effects of age, sex and rheumatoid factor on survival. DATA: In the 1965, 1975 and 1985 prevalence cohorts, there were 163, 235 and 272 cases of RA, respectively. Some individuals were present in more than one. Deaths in each cohort were 54, 93 and 111, respectively. Median follow-up was 12.7 years for the entire group with the earlier groups being longer. Mean follow-up was 15.1 years. Seventy-three percent of patients were females. The average age at diagnosis was 60.2 years.