Prevalence of anaemia in adults with chronic kidney disease in a representative sample of the United States population: analysis of the 1999-2018 National Health and Nutrition Examination Survey.

Background: Population-based estimates of anaemia prevalence in patients with chronic kidney disease (CKD) vary, and data on the prevalence of severe anaemia of CKD are limited. This study examined the prevalence of anaemia and anaemia eligible for erythropoiesis-stimulating agent (ESA) treatment in patients with CKD in the USA.

Methods: National Health and Nutrition Examination Survey (NHANES) data from 1999-2000 to 2017-18 were used to determine the prevalence of diagnosed anaemia (haemoglobin <12 g/dL in women; <13 g/dL in men) and anaemia eligible for ESA treatment (haemoglobin <10 g/dL) in survey participants aged ≥18 years with stage 3-5 non-dialysis-dependent CKD (estimated glomerular filtration rate <60 mL/min/1.73 m). The study objectives were to (i) obtain a more recent estimate of anaemia prevalence in patients with non-dialysis-dependent CKD and (ii) examine the characteristics of individuals with CKD and haemoglobin <10 g/dL.

Results: Of 51 163 eligible NHANES participants, 2926 (5.7%) with stage 3-5 CKD were included. In all participants, the weighted prevalences of anaemia and haemoglobin <10 g/dL were 25.3% and 1.9%, respectively. Mean haemoglobin levels decreased numerically between 1999 and 2012 and remained stable thereafter. The prevalence of anaemia and haemoglobin <10 g/dL increased with advancing CKD stage. The odds of haemoglobin <10 g/dL were significantly higher in stage ≥3B versus 3A and in non-Hispanic Blacks versus other races.

Conclusions: In our analysis, approximately 25% of individuals with stage 3-5 CKD in the USA had anaemia and approximately 2% had anaemia eligible for ESA treatment.