Undertreatment of Anemia in Patients with Chronic Kidney Disease in the United States: Analysis of National Outpatient Survey Data

Abstract

Background: Understanding anemia treatment patterns in national outpatient settings may assist evidence-based policy making by identifying the variations in physician prescriptions for chronic kidney disease (CKD) and reasons for such variations. Objective: The aim of this study was to examine anemia management patterns of CKD in outpatient settings in the United States. Methods: This cross-sectional study used data from the US National Ambulatory Medical Care Survey (NAMCS) from 1996 to 2002. Patients aged ⩾18 years with CKD were included in the study sample. Office visits were considered CKD-related if relevant International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes were recorded and if CKD was reported as a reason for the visit. Similarly, visits were considered anemia related if relevant ICD-9-CM codes were recorded and if anemia was reported as a reason for the visit or if anemia-related laboratory testing (eg, hematocrit) was ordered. Anemia medications (ie, erythropoietic-stimulating agents or iron replacement) were retrieved using the NDC drug codes. All analyses were statistically weighted using the NAMCS sampling weights to make national estimates. Results: From 1996 to 2003, there were 2234 unweighted CKD-related patient visits in the outpatient setting, representing ~92 million weighted outpatient visits. The majority of these visits were made by women (63%) and patients aged ≥65 years (54%). Of these visits, 18% were to a nephrologist. Anemia-management issues were also recorded at nearly half (48%) of all CKD outpatient visits. Ten percent of visits for anemia management resulted in an anemia medication prescription. Patients on Medicare (odds ratio [OR], 0.49; 95% CI, 0.32–0.74) were less likely and those assessed previously (OR, 4.25; 95% CI, 1.66–10.88) were more likely to receive an anemia medication prescription. Conclusions: The findings of this study suggest that ~10% of CKD-related visits addressing anemia management are receiving anemia medications in US out-patient settings. Most CKD-patient visits were to primary care physicians (PCPs) and physicians other than nephrologists. PCPs were most likely to diagnose anemia but were less likely to prescribe anemia medications.