Trends in the incidence and mortality of systemic lupus erythematosus, 1950-1992

Objective. To describe trends in systemic lupus erythematosus (SLE) inciden ce and mortality over the past 4 decades. Methods. Using the Rochester Epidemiology Project resources, medical record s were screened to identify all Rochester, Minnesota residents with any SLE -associated diagnoses, discoid lupus, positivity for antinuclear antibodies , and/or false-positive syphilis test results determined between January 1, 1980 and December 31, 1992, Medical records were then reviewed using a pre tested data collection form in order to identify cases of SLE according to the American College of Rheumatology 1982 revised criteria for SLE, Drug-in duced cases were excluded. All identified SLE patients were followed up unt il death, migration from the county; or October 1, 1997, These data were co mbined with similar data from the same community obtained between 1950 and 1979, and trends in the SLE incidence and mortality over time were calculat ed, Results. Of the 430 medical records reviewed, 48 newly diagnosed cases of S LE (42 women and 6 men) were identified between 1980 and 1992, The average incidence rate (age- and ses-adjusted to the 1970 US white population) was 5.56 per 100,000 (95% confidence interval [95% CI] 3.93-7.19), compared wit h an incidence of 1.51 (95% CI 0.85-2.17) in the 1950-1979 cohort. The age- and ses-adjusted prevalence rate as of January 1, 1993 was similar to 1.22 per 1,000 (95% CI 0.97-1.47). Survival among SLE patients nas significantl y worse than in the general population (P = 0.017 compared with the 1980-19 92 cohort, and P < 0.0001 compared with the 1950-1979 cohort, bq log-rank t est). Cos proportional hazards modeling demonstrated a statistically signif icant improvement in the survival rate over time (P = 0.035). Conclusion. Over the past 1 decades, the incidence of SLE has nearly triple d, and there has been a statistically significant improvement in survival. These findings are likely due to a combination of improved recognition of m ild disease and better approaches to therapy.