Population Risk Predictors of Major Adverse Kidney Events in Patients with Focal Segmental Glomerulosclerosis from the CURE-CKD Registry

Background Predictors of major adverse kidney events (MAKE) in focal segmental glomerulosclerosis (FSGS) have not been previously explored within large, real-world populations. The study aim was to evaluate population-level predictors of MAKE for patients with FSGS from health system data. Methods The study population was derived from electronic health records from Providence and University of California Los Angeles Health. Cox proportional hazards models were used to estimate the effects of clinical and non-clinical variables including age, gender, race and ethnicity, health system, health insurance, healthcare utilization, estimated glomerular filtration rate (eGFR), diabetes, hypertension, and prescription medications as predictors of MAKE defined as: ≥40% eGFR decline, kidney failure (eGFR <15 mL/min/1.73 m ² , administrative codes for kidney failure, dialysis, or transplant) and death. Results Adults with FSGS (N=629) were 54% (n=342) men and 53±17 (mean±SD) years old. Baseline eGFR was 60±30 mL/min/1.73 m ² , while median (interquartile range) urine albumin/creatinine ratio (UACR) and urine protein/creatinine ratio (UPCR) were 1,430 (520-2,630) mg/g and 1.6 (0.5-3.9) g/g, respectively. Angiotensin converting enzyme inhibitors or angiotensin receptor blockers were prescribed to 76% (n=475), while corticosteroids and other immunomodulators were prescribed in 47% (n=297) and 12% (n=74), respectively. MAKE were observed in 42% (n=262) of study participants over a median of 2.9 (1.4-4.5) years. Higher hazard for MAKE was associated with above-median UACR or UPCR (HR [95% CI] (3.46 [2.28-5.23]) in patients with available measures, prescription for non-corticosteroid immunomodulator (1.87 [1.32-2.65]), non-commercial health insurance (1.78 [1.36-2.33]), hospitalization (1.64 [1.25-2.15]), lower eGFR per 10 mL/min/1.73 m ² 1.25 [1.18-1.32]), number of outpatient visits (1.03 [1.01-1.05]) and lower hazard for MAKE was associated with older age (0.89 [0.82-0.98]). Conclusions Substantial loss of kidney function or kidney failure occurred in more than four in ten patients with FSGS by a median of three years. MAKE were predicted by unique population level factors, such as healthcare utilization and insurance type, which may help to identify patients with FSGS, who could most benefit from diagnostic testing and interventions to improve clinical outcomes.