Abstract
OBJECTIVE: Persons with low socioeconomic status have an increased risk of endstage renal disease (ESRD) due to systemic lupus erythematosus (SLE), possibly because of limited access to care. We examined if the incidence of ESRD due to SLE was higher in geographic areas with poorer access to care. METHODS: In this population-based ecological study, we tested associations between the incidence of ESRD due to SLE and the proportion of hospitalizations with no insurance, Medicaid or managed care insurance, residence in a primary care-provider shortage area or rural area, and rate of hospitalizations for ambulatory care-sensitive conditions, by ZIP code in California in 1999-2004. RESULTS: The incidence of ESRD due to SLE was higher in ZIP codes with higher proportions of hospitalizations with no insurance (r = 0.22, p < 0.0001) or Medicaid (r = 0.21, p < 0.0001), and in ZIP codes with higher rates of hospitalizations for ambulatory care-sensitive conditions (r = 0.23, p < 0.0001). In multivariate analyses, incidences were higher in ZIP codes with higher proportions of hospitalizations with Medicaid (p < 0.0001) and higher rates of hospitalizations for ambulatory care-sensitive conditions (p = 0.06), independent of the socioeconomic status of the ZIP code residents. CONCLUSION: The incidence of ESRD due to SLE is higher in areas with higher proportions of residents who have public insurance and higher rates of avoidable hospitalizations, suggesting that limited access to care may contribute to this complication of SLE.