Referral rate of chronic kidney disease patients to a nephrologist in the Region of Southern Denmark: results from KidDiCo

Lay Summary Only a few patients are aware of having chronic kidney disease (CKD). Being followed by a specialist nephrologist is important, e.g. in terms of slowing down kidney disease progression, cardiovascular disease prevention and end-stage kidney disease management initiation, including dialysis and kidney transplantation. We performed a cohort study using data from patients from the region of Southern Denmark. With the help of certain diagnostic codes for outpatients in the cohort, we were able to identify patients who were followed by a nephrologist and those who were not. Our study found that only 16% of patients who, according to current guidelines, should be followed by a nephrologist were actually followed. Predictors for nephrology follow-up included younger and male, having diabetes and/or hypertension, patients with higher education and patients living close to a nephrologist. New strategies for improving outpatient care of patients with CKD have to be considered. Background Data on the referral rate of chronic kidney disease (CKD) patients to specialists are sparse. Investigating referral rates and characterizing patients with kidney disease not followed by a nephrologist are relevant for future measures in order to optimize public health and guideline implementation. Methods Data were extracted from the Kidney Disease Cohort of Southern Denmark (KidDiCo). Referral rates for all incident CKD patients below 60 mL/min/1.73 m(2) and referral rates according to the KDIGO guidelines based on glomerular filtration rates below 30 mL/min/1.73 m(2) were calculated. Information on contact with one of the nephrologist outpatient clinics in the Region of Southern Denmark was collected from the Danish National Patient Registry. The individual follow-up time for nephrology contact was 12 months. Additional data were accessed via the respective national databases. CKD patients on dialysis and kidney transplanted patients were excluded. Results A total of 3% of patients with an eGFR -16% of patients with an eGFR <30 mL/min/1.73 m(2) and 35% of patients with an eGFR <15 mL/min/1.73 m(2) were in contact with a nephrologist in the outpatient settings. Younger age, male sex, diabetes, hypertension, higher education and proximity to a nephrology outpatient clinic increased the chance of nephrology follow-up. Conclusion Only a small fraction of CKD patients are followed by a nephrologist. More studies should be performed in order to find out which patients will profit the most from renal referral and how to optimize the collaboration between nephrologists and general practitioners.