The incidence, prevalence, and outcomes of glomerulonephritis derived from a large retrospective analysis

The incidence and period prevalence of glomerulonephritis (GN) with resultant rates of death and end-stage renal disease (ESRD) in the United States are unknown. Therefore, we assessed the presumptive burden of GN in a 20% Medicare sample, 5,442,495 individuals, and an Optum Clinformatics Employer Group Health Plan sample of 13,712,946 individuals. GN was established using International Classification of Diseases, Ninth Revision, Clinical Modification claims-based algorithms. Outcomes were all-cause mortality and ESRD rates. Cox proportional hazards modeling was used to determine factors associated with outcomes in incident patients. For secondary (systemic immunologic disease) and primary GN, respectively, incidence rates per 100,000 patient-years were 134 (95% CI: 132–136) and 57 (56–58) in the Medicare cohort, and 10 (9–10) and 20 (19–21) in the health plan cohort. Period prevalence per 100,000 individuals was 917 (909–952) and 306 (302–311) in Medicare and 52 (51–54) and 70 (68–71) in the health plan. Death rates in incident Medicare patients were 3.9-fold higher for secondary and 2.7-fold higher for primary GN compared with no GN. ESRD rates were typically 1 to 2 orders of magnitude higher compared with no GN. In the Medicare cohort, women with incident secondary GN were less likely than men to progress to ESRD (hazard ratio: 0.70; 95% CI: 0.62–0.80) and death (0.82; 0.79–0.86). Black patients were more likely than white patients to progress to ESRD (secondary GN, 1.56; 1.31–1.85; primary GN, 1.57; 1.35–1.83), but not to death. Thus, in the United States, GN based on health claims data is associated with increased likelihood of progression to ESRD and death.