Background: Clinical practice guidelines recommend referral to nephrology when estimated glomerular filtration rate (eGFR) decreases to <30mL/min/1.73m2; however, evidence for benefits of nephrology care are mixed.
Study design: Observational cohort using landmark analysis.
Settings & participants: A national cohort of veterans with advanced chronic kidney disease, defined as an outpatient eGFR≤30mL/min/1.73m2 for January 1, 2010, through December 31, 2010, and a prior eGFR<60mL/min/1.73m2, using administrative and laboratory data from the Department of Veterans Affairs and the US Renal Data System.
Predictor: Receipt and frequency of outpatient nephrology care over 12 months.
Outcomes: Survival and progression to end-stage renal disease (ESRD; receipt of dialysis or kidney transplantation) were the primary outcomes. In addition, control of associated clinical parameters over 12 months were intermediate outcomes.
Results: Of 39,669 patients included in the cohort, 14,983 (37.8%) received nephrology care. Older age, heart failure, dementia, depression, and rapidly declining kidney function were independently associated with the absence of nephrology care. During a mean follow-up of 2.9 years, 14,719 (37.1%) patients died and 4,310 (10.9%) progressed to ESRD. In models adjusting for demographics, comorbid conditions, and trajectory of kidney function, nephrology care was associated with lower risk for death (HR, 0.88; 95% CI, 0.85-0.91), but higher risk for ESRD (HR, 1.48; 95% CI, 1.38-1.58). Among patients with clinical parameters outside guideline recommendations at cohort entry, a significantly higher adjusted proportion of patients who received nephrology care had improvement in control of hemoglobin, potassium, albumin, calcium, and phosphorus concentrations compared with those who did not receive nephrology care.
Limitations: May not be generalizable to nonveterans.
Conclusions: Among patients with advanced chronic kidney disease, nephrology care was associated with lower mortality, but was not associated with lower risk for progression to ESRD.
Keywords: CKD progression; Chronic kidney disease (CKD); delivery of health care; disease trajectory; end-stage renal disease (ESRD); guideline-concordant care; immortal time bias; intensity of care; landmark analysis; nephrology; nephrology care; nephrology referral.
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