Prevalence and incidence of systemic lupus erythematosus and associated outcomes in the 2009–2016 US Medicare population

Abstract

Objectives We aimed to update data on the prevalence and incidence of systemic lupus erythematosus (SLE) in the Medicare population and describe associated outcomes. Methods This observational study used Medicare 20% random sample data 2007–2016 to estimate SLE prevalence and incidence 2009–2016. The study population included patients aged ≥18 years (stratified by <65 and ≥65 years) with Medicare fee-for-service coverage. The SLE definition was based on a published and validated algorithm. All-cause death, hospitalizations, and kidney disease incidence were defined for a prevalent SLE cohort 2011–2015. Unadjusted event rates during 5-year follow-up were reported per 100 patient-years. Results The study included > 5 million eligible patients for each year 2009–2016. There were 19,518 (10,898, aged ≥65; 8620, aged <65) in 2016, extrapolated to 97,590 (54,490 aged ≥65; 43,100 aged <65) in the overall 2016 Medicare population. Age- and sex-adjusted prevalence rates (per 100,000 Medicare population) ranged from 301.1 in 2009 to 366.6 in 2016, all ages, and 184.0–239.9, ≥65 years. There were 2614 (1844 aged ≥65; 770 aged <65) incident patients in 2016; age-/sex-adjusted incidence rates (per 100,000 Medicare population) ranged from 46.9 in 2009 to 49.0 in 2016, all ages, and 37.5–40.8, ≥65. Five-year unadjusted mortality, elderly vs. younger, was 8.8 vs. 3.8, morbidity 34.5 vs. 32.4, and kidney disease incidence 19.8 vs. 18.0 per 100 patient-years. Conclusions Prevalence rates steadily increased while incidence was relatively stable 2009–2016. Our data should be interpreted with caution due to our elderly study population.