Impact of Using Risk-Based Stratification on Referral of Patients With Chronic Kidney Disease From Primary Care to Specialist Care in the United Kingdom.

Introduction: The externally validated Kidney Failure Risk Equation (KFRE) for predicting risk of end-stage renal disease (ESRD) has been developed, but its potential impact in a population on referrals for patients with chronic kidney disease (CKD) from primary to specialty nephrology care is not known.

Methods: A cross-sectional population-based study of individuals in United Kingdom primary care registered in The Health Improvement Network database was conducted. National Institute of Health and Care Excellence (NICE) 2014 CKD guidelines the 4-variable KFRE set at a >3% risk of ESRD at 5 years were applied to patients identified with CKD stage 3-5 between January 1, 2016, and March 31, 2017.

Results: In all, 39,476 (36.6%) of 107,962 adults with CKD stage 3-5 had a urine albumin:creatinine ratio (ACR) available and entered into the primary analysis. Of that, 7566 (19.2%) patients fulfilled NICE criteria for referral, 2386 (31.5%) of whom had a ≤3% 5-year risk of ESRD. Also 8663 (21.9%) patients had a >3% 5-year risk of ESRD, 3483 (40.2%) of whom did not fulfill NICE criteria; this represents 8.8% of the primary population. By using the KFRE threshold rather than NICE criteria for referral, 5869 patients (14.9% of the primary analysis population) would have been reallocated between primary and specialist care. Imputational analysis was used for missing ACR measurements and showed similar results.

Conclusions: A risk-based referral approach would lead to a substantial reallocation of patients between primary care and specialist nephrology care with only a small increase in numbers eligible, ensuring those at higher risk of progression are identified.