Kidney Failure Attributed to Focal Segmental Glomerulosclerosis: A USRDS Retrospective Cohort Study of Epidemiology, Treatment Modalities, and Economic Burden

Abstract

Rationale & ObjectiveThis study describes the epidemiology, characteristics, and clinical outcomes of patients with focal segmental glomerulosclerosis (FSGS)-attributed kidney failure in the US Renal Data System (USRDS) during 2008-2018, and healthcare resource utilization and costs among those with Medicare-linked data. Study DesignRetrospective cohort study Setting & PopulationPatients with FSGS-attributed kidney failure in the USRDS OutcomesPrevalence/incidence, clinical/demographic characteristics, time to kidney transplant/death, healthcare resource utilization, direct healthcare costs Analytical ApproachPatients with FSGS as the primary cause of kidney failure were followed from USRDS registration (index date) until death/data end. Prevalence/incidence were calculated per 1,000,000 US persons. Patient characteristics at index and treatment modalities during follow-up were described. Time to kidney transplant/death was assessed with Kaplan-Meier and competing risk analyses. Healthcare resource utilization and costs were reported among patients with 1 year Medicare Part A+B coverage post-index, including (Medicare Coverage subgroup) or excluding (1-year Medicare Coverage subgroup) those who died. ResultsThe FSGS cohort and Medicare Coverage and 1-year Medicare Coverage subgroups included 25,699, 6,340, and 5,575 patients, respectively. Mean annual period prevalence and incidence rates of FSGS-attributed kidney failure were 87.6 and 7.5 per 1,000,000 US persons, respectively. Initial treatment for most patients was in-center hemodialysis (72.1%), while 7.3% received kidney transplant. Accounting for competing risk of death, Year 1 and 5 kidney transplant rates were 15% and 34%, respectively. In the Medicare Coverage and 1-year Medicare Coverage subgroups, 76.6% and 74.2%, respectively, required inpatient admission, 69.9% and 67.3% visited the emergency room, and mean monthly healthcare costs were $6,752 and $5,575 in the year post-index. LimitationsDrug costs may be underestimated as Medicare Part D coverage was not required; kidney acquisition costs were not available. ConclusionsFSGS-attributed kidney failure is associated with substantial clinical and economic burdens, prompting the need for novel therapies for FSGS to delay kidney failure.