Kidney Medicine (Feb 2024)
Kidney Failure Attributed to Focal Segmental Glomerulosclerosis: A USRDS Retrospective Cohort Study of Epidemiology, Treatment Modalities, and Economic Burden
Abstract
Rationale & Objective: This 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 health care resource utilization and costs among those with Medicare-linked data. Study Design: This was a retrospective cohort study. Setting & Population: Patients with FSGS-attributed kidney failure in the USRDS were enrolled in the study. Outcomes: The outcomes were as follows: Prevalence and incidence, clinical and demographic characteristics, time to kidney transplant or death, health care resource utilization, and direct health care costs. Analytical Approach: Patients with FSGS as the primary cause of kidney failure were followed from USRDS registration (index date) until death or data end. Prevalence and 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 or death was assessed with Kaplan-Meier and competing risk analyses. Health care resource utilization and costs were reported among patients with 1 year Medicare Part A+B coverage postindex, including (Medicare Coverage subgroup) or excluding (1-year Medicare Coverage subgroup) those who died. Results: The 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%), whereas 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% required inpatient admission, 69.9% and 67.3% visited the emergency room, and mean monthly health care costs were $6,752 and $5,575 in the year postindex, respectively. Limitations: Drug costs may be underestimated because Medicare Part D coverage was not required; kidney acquisition costs were not available. Conclusions: FSGS-attributed kidney failure is associated with substantial clinical and economic burden, prompting the need for novel therapies for FSGS to delay kidney failure. Plain-Language Summary: This study of patients in the US Renal Data System observed increasing prevalence and fluctuating incidence of focal segmental glomerulosclerosis (FSGS)-attributed kidney failure from 2008 to 2018. Patients experienced a high clinical burden, including more than 3 years of treatment with dialysis, one-third receiving a kidney transplant, and one-third dying during follow-up. In the first year after US Renal Data System registration, three-quarters of patients with Medicare coverage required hospitalization, and more than two-thirds visited the emergency room. The total annual health care costs were >$68,000 per patient with FSGS-attributed kidney failure, underscoring the high economic burden of this disorder and the treatments required to sustain life. Novel therapies for FSGS are needed to delay or ideally prevent the need dialysis and transplantation after kidney failure.
