Prevalence of chronic kidney disease stages 3-5 among acute medical admissions: another opportunity for screening

Abstract

Background: Early identification of chronic kidney disease (CKD) can help delay or prevent its progression, but the opportunities for systematic screening of patients are not well defined. Aim: To define the prevalence of CKD Stages 3–5 and related anaemia among acute medical admissions. Design: Retrospective analysis. Methods: We studied all acute medical admissions to a major London teaching hospital during one year. The lowest creatinine, highest haemoglobin (Hb) and average mean corpuscular volume (MCV) were determined for 3 months before and after admission. Patients were categorized as CKD Stages 3–5 if the highest estimated GFR (eGFR) was 2. CKD-related anaemia was diagnosed if these patients had Hb Results: A total of 6073 patients were studied: male 49.0%, age 65.4 ± 19.6 years (mean ± SD), creatinine 82.7 ± 46.7 µmol/l, eGFR 89.1 ± 32.5 ml/min/1.73 m², Hb 13.6 ± 1.73 g/dl, MCV 87.7 ± 7.2 fl. There was an inverse correlation between eGFR and age (r² = 0.5; P < 0.001). Males were younger than females (63.5 ± 18.4 years vs. 67.3 ± 20.5) and had higher eGFR (93.6 ± 34.1 vs. 84.7 ± 30.2 ml/min/1.73 m²; P < 0.001). A total of 743 patients (12.2%) had raised creatinine >110 µmol/l, however using eGFR 2, 1075 patients (17.7%) were identified. The patients were categorized as follows: Stage 3: 950 (15.6%), Stage 4: 100 (1.7%), Stage 5: 25 (0.4%). Ninety-nine (9.2%) of the 1075 patients had normocytic anaemia. Conclusions: We have found a high prevalence of CKD Stages 3–5 (17.7%) among acute medical admissions, of whom 9.2% had a related anaemia. Our findings highlight an important opportunity (amongst the 1.9 million acute medical admissions annually in England) for detecting patients with CKD.