Anemia is a common comorbidity in patients with chronic kidney disease (CKD); however, there are few data available on the long-term clinical burden of anemia in that patient population. Eric Wittbrodt, PharmD, MPH, and colleagues conducted an analysis to examine selected cardiovascular and renal outcomes in non-dialysis CKD patients with and without anemia at baseline. Results of the retrospective observational study were reported during the NKF Spring Clinical Meetings in a presentation titled Clinical Outcomes in Patients with Anemia in CKD Using Linked US Claims and Electronic Health Records Data.
The cohort included patients in a real-world practice in the United States. The researchers utilized the integrated Limited Claims and Electronic Health Record data (IBM Health, Armonk, New York). Patients were ≥18 years of age with two or more estimated glomerular filtration rate (eGFR) measurements <60 mL/min/1.73 m2 ≥90 days apart. The study defined anemia as the presence of any observed hemoglobin <10 g/dL within 6 months of confirmatory eGFR (anemia baseline period). The baseline period for disease history was defined as the start of patient data + 6 months; baseline for laboratory measures and medication use was defined as the date of the second confirmatory eGFR + 6 months.
Exclusion criteria were active bleeding, chronic dialysis, and iron deficiency anemia. The study examined baseline patient characteristics and clinical outcomes during follow-up for the period January 1, 2012, to September 30, 2017. Descriptive data were summarized and no inferential statistics were performed.
The total study cohort included 22,720 patients. Of those, 5283 (23%) had baseline hemoglobin <10 g/dL. In the CKD with anemia group, 60% were female, mean age was 70 years; 50% had CKD stage 3a, 27% CKD stage 3b, 15% CDK stage 4, and 9% CKD stage 5. Mean follow-up was 2.9 years. In the CKD without anemia group, 56% were female, mean age was 70 years; 68% had CKD stage 3a, 24% CKD stage 3b, 6% CKD stage 4, and 1% CKD stage 5. Mean follow-up was 3.8 years.
During follow-up, acute coronary syndrome (ACS) events occurred in 2.3% of patients with and without baseline anemia, heart failure hospitalizations occurred in 6.0% and 3.7%, and stroke hospitalizations and emergency visits occurred in 2.8% and 3.7% of those with and without anemia at baseline, respectively. In the groups with and without anemia at baseline, total event (initial and recurrent) rates per 100 patients per year were 0.86 and 0.70 for ACS, 2.84 and 1.43 for heart failure hospitalizations, and 0.84 and 0.78 for stroke hospitalizations and emergency visits, respectively.
In the with and without anemia-at-baseline groups, end-stage renal disease occurred in 44% and 25%, respectively. Progression of CKD stage occurred in 67% and 59% of patients in the with and without anemia at baseline groups, respectively. The median change in eGFR slope in the groups with and without anemia at baseline groups –0.6 and –0.3 mL/min/1.73 m2, respectively.
“This analysis highlights worsened outcomes associated with anemia in CKD, particularly hospitalization for heart failure and eGFR decline, in patients of a large US cohort,” the researchers said.
Source: Wittbrodt E, James G, Kumar S, et al. Clinical outcomes in patients with anemia in CKD using linked US claims and electronic health records data. Abstract of a presentation at the National Kidney Foundation 2020 Spring Clinical Meetings; abstract #196.