Association of physician care with mortality in Kidney Early Evaluation Program (KEEP) participants

People with or at high risk of chronic kidney disease (CKD) are at increased risk of premature morbidity and mortality. We sought to examine the effect of care provided by a primary care physician (PCP) on survival for all participants in the National Kidney Foundation's Kidney Early Evaluation Program (KEEP) and the effect of care provided by a nephrologist on survival for KEEP participants with estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2).

Provision of care by a PCP (n = 138,331) or nephrologist (n = 10,797) was defined using self-report of seeing that provider within the past year. Survival was ascertained by linking KEEP data to the Social Security Administration Death Master File. Multivariable Cox proportional hazards models examining the relationship between primary care and nephrologist provider status adjusted for age, sex, race, smoking status, education, health insurance, diabetes, cardiovascular disease, hypertension, cancer, albuminuria, body mass index, baseline eGFR, and hemoglobin level, with nephrology models further adjusting for calcium, phosphorus, and parathyroid hormone levels.

Of all participants, 70.9% (98,050 of 138,331) reported receiving PCP care; older age and female sex were associated with this care. During a median follow-up of 4.2 years, 4,836 deaths occurred. After multivariable adjustment, receiving PCP care and mortality were not associated (HR, 0.94; 95% CI, 0.86-1.03; P = 0.2). Of participants with eGFR <60 mL/min/1.73 m(2), 10.1% (1,095 of 10,797) reported receiving nephrology care; younger age and male sex were associated with receipt of nephrology care. During a mean follow-up of 2.2 years, 558 deaths occurred. After multivariable adjustment, nephrologist care was not associated with mortality (HR, 1.01; 95% CI, 0.75-1.36; P = 0.9). These associations were not modified by other specialist care (endocrinologist or cardiologist).

For all KEEP participants, neither PCP nor nephrology care was associated with improved survival. These results highlight the need to explore the connection between access to health care and outcomes in persons at high risk of or with CKD.