Incidence and prevalence of adult systemic lupus erythematosus in a large US managed-care population

Abstract

Objective The objective of this paper is to determine the incidence and prevalence of adult systemic lupus erythematosus (SLE) in a large US managed-care population. Methods Subject inclusion in the incidence cohort required a medical claim with an SLE diagnosis and a service date from 2003 to 2008 that satisfied the following criteria: 1) ≥18 years on service date; 2) continuously enrolled for 24 months before and 12 months after service date; 3) in the 12 months after service date, ≥ one inpatient claim or ≥ two office or ER visits with an SLE diagnosis; 4) no SLE diagnosis 24 months prior to service date; and 5) no SLE medications 12 months prior to service date. Prevalence cohort subjects were identified using a similar algorithm and were not required to satisfy criteria 4) and 5). Results A total of 1,557 subjects were included in the incidence cohort, and 15,396 were included in the prevalence cohort. The overall age- and gender-adjusted SLE incidence rate (2003–2008) was 7.22 cases per 100,000 person-years. The annual prevalence of SLE (per 100,000 individuals) varied from 81.07 in 2003 to 102.94 in 2008. Conclusion The SLE incidence in this large managed-care plan with geographic diversity was slightly higher than previous estimates, and the prevalence was within the range of previous estimates.