Undertreatment of anemia in patients with chronic kidney disease in the United States: analysis of national outpatient survey data.

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 approximately 92 million weighted outpatient visits. The majority of these visits were made by women (63%) and patients aged > or =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 approximately 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.