Prevalence of iron deficiency in patients with non-dialysis chronic kidney disease: The CARENFER national, multicentre, observational study

Introduction. - Iron deficiency is common and associated with worse outcomes in patients with non-dialysis chronic kidney disease. We performed a national, multicentre, observational and transversal study to assess the prevalence of iron deficiency as well as current iron deficiency screening practices in this population. Patients and methods. - A total of 25 nephrology centres in France participated in the study. All adult non-dialysis chronic kidney disease patients who met the inclusion (GFR > 15 mL/min/1.73 m(2)) and exclusion criteria and provided consent were systematically recruited over a 4-week inclusion period. Investigators were asked to perform a blood test (hemoglobin concentration, serum iron, serum ferritin and transferrin saturation) and to complete a questionnaire about their iron status monitoring practices. The primary objective was to assess the prevalence of iron deficiency (serum ferritin < 100 mg/L and/or transferrin saturation < 20%). Secondary objectives were to evaluate the prevalence of absolute iron deficiency (serum ferritin < 100 mg/L and transferrin saturation < 20%) and functional iron deficiency (serum ferritin >= 100 mg/L and transferrin saturation < 20%), the prevalence of iron deficiency according to haemoglobin concentration and chronic kidney disease stage, the proportion of centres that perform routine evaluation of iron status and the number of patients receiving iron supplementation. Results. - A total of 1211 patients with non-dialysis chronic kidney disease were included in the analysis. The overall prevalence of iron deficiency was 47.1%. The rates of absolute iron deficiency and functional iron deficiency and anaemia were 13.4% and 17.1%, respectively. Among the 25 participating centres, 12 reported routine assessment of iron status in non-dialysis chronic kidney disease patients. Conclusion. - In this observational study, a high prevalence of iron deficiency was observed among non-dialysis chronic kidney disease patients. Less than half of participating centres reported routine assessment of iron status. (C) 2022 Published by Elsevier Masson SAS on behalf of Societe francophone de nephrologie, dialyse et transplantation.