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.

Keywords: Medicare; SLE; Systemic lupus erythematosus; incidence; outcome; prevalence.