WASHINGTON—Researchers who studied a cohort of patients with non-dialysis-dependent chronic kidney disease (CKD) found that nearly one-quarter of them had severe anemia, according to a presentation at the American Society of Nephrology’s Kidney Week 2019 meeting.

At baseline, out of 22,720 patients with CKD stages 3a to 5, 5283 (23.3%) had severe anemia, defined as a hemoglobin level below 10 g/dL and making patients eligible for treatment, Eric T. Wittbrodt, PharmD, MPH, of AstraZeneca in Gaithersburg, Maryland, and colleagues reported in a poster presentation. The inpatient and outpatient prevalence of anemia was 32.6% and 21.2%, respectively. Among patients without anemia at baseline, the incidence rate for developing anemia over 5 years was 8.92 per 100 person-years.

Results showed that anemia persistence overall—defined as uninterrupted hemoglobin levels below 10 g/dL—was substantial and greater than anemia recurrence during follow-up, according to the investigators. For the overall study population, the incidence rates for anemia persistence and recurrence were 3.17 and 0.89 per 100 person-years, respectively. Among the patients with anemia at baseline, rates were 10.83 and 2.13 per 100 person-years, respectively. For the 17,437 patients without anemia at baseline, the rates were 1.59 and 0.29 per 100 person-years, respectively.

Dr Wittbrodt’s team analyzed data from a large US electronic medical record database linked to to insurance claims. The study population had a mean age of 70.4 years and mean follow-up period of 3.36 years. Of the 22,720 patients, 63.9%, 24.9%, 8.5%, and 2.7% had CKD stage 3, 3a, 4, and 5, respectively.

In a separate study of 2007-2010 data from the National Health and Nutrition Examination Survey (NHANES) presented at the conference, Jill Davis, MS, of AstraZeneca in Wilmington, Delaware, and colleagues found that the US prevalence of anemia among adults—defined as a hemoglobin level of 13 g/dL or less for men and 12 g/dL or less for women—was 23.5%. The prevalence of severe anemia (hemoglobin level below 10 g/dL) was 1.2%.

According to Dr Wittbrodt, the main reason for the disparity in prevalence of severe anemia between his study and the one by Davis and colleagues was that his study looked at period prevalence (hemoglobin level less than 10 g/dL at any point in time 6 months before and after the index date), whereas the NHANES analysis used point prevalence (ie, hemoglobin level below 10 g/dL at one point in time). Also, the current analysis included hemoglobin levels from both inpatients and outpatients.

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Reference

Wittbrodt ET, James G, Kumar SR et al. Prevalence of CKD anemia in non-dialysis-dependent patients using linked US claims and electronic health record data. Presented at the American Society of Nephrology’s Kidney Week 2019 meeting held November 5 to 10 in Washington, DC. Poster SA-PO242.