Early Versus Late Referral to Specialist Nephrology Services - A Systematic Review

Aim: To determine the effect of early versus late nephrology referral on clinical outcomes in people with chronic kidney disease (CKD). Background: Later referral to specialist nephrology services results in significant morbidity and mortality. Methods: A systematic literature search was performed to identify relevant studies to February 2012. Studies compared adult patients with CKD (eGFR<30 mL/min/1.73 m²) referred for evaluation to nephrology services early versus those referred later. Two authors independently assessed study eligibility and extracted data. Risk of bias was assessed using the Newcastle-Ottawa Scale for non-randomised studies. Meta-analyses were performed using a random effects model, expressed as relative risk (RR) with 95%CI. Results: Forty cohort studies (9 prospective and 31 retrospective) of 63,887 participants were included. There were no existing randomised control trials. Mortality was reduced in early referrals at all time points with RR 0.47 (95%CI 0.29-0.76) at 3 months, RR 0.58 (95%CI 0.42-0.79) at 6 months, RR 0.56 (95%CI 0.47-0.67) at 12 months and RR 0.71 (95%CI 0.54-0.94) at 5 years. Initial hospitalisation duration was also reduced in early referrals by 9.1 days (95%CI 7.3-10.9). Early referrals were approximately 60% more likely to start dialysis with a peritoneal catheter (RR 1.59 95%CI 1.23-2.05) and 60% less likely to start with a temporary vascular catheter (RR 0.41 95%CI 0.30-0.56). Late referrals were 78% less likely to start with permanent vascular access (RR 0.22 95%CI 0.12-0.40). Conclusions: Preventing one patient starting haemodialysis with temporary vascular access and to achieve one more patient starting with permanent access, requires just three early CKD referrals. Early referral of 12 CKD patients was enough to prevent one death within the first year of renal replacement therapy.