Defense Date

2010

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Pharmaceutical Sciences

First Advisor

David Holdford

Abstract

Background: Chronic kidney disease (CKD) affects approximately 20 million Americans and is the cause of significant morbidity and mortality. Anemia, common in CKD, develops early in the disease process. It contributes to increased risk of cardiovascular disease, hospitalization, mortality, and diminishes health-related quality of life. Intravenous iron and Erythropoiesis Stimulating Agents (ESAs) are recommended for anemia management in CKD. The utilization patterns of IV iron and ESA, and their impact on hospital costs and length of stay merits investigation. Objectives: There were five general objectives of this investigation. The rate and extent of utilization of IV iron in anemic CKD patients was quantified across teaching hospitals in the US. Patient characteristics of those receiving IV iron and ESA and ESA alone were evaluated in detail. Predictors of IV iron and ESA use were determined. The impact of IV iron and ESA use was examined separately for total hospital costs and length of stay (LOS) while adjusting for confounding. Methods: This is a retrospective cohort analysis within the University Health System Consortium data warehouse. Eligible patients are those who were admitted to a hospital and received either IV iron and ESA or both at least once during the period of January 1, 2006, and December 31, 2008. Inclusion criteria include age > 18 years old with a primary or secondary diagnosis of CKD. The exposure of interest was IV iron and ESA therapy, and the outcome was the difference in total hospital costs and length of stay between patients only on ESA, and those on ESA and IV iron. A clustered binomial logistic regression using the GEE methodology was used to identify predictors of IV iron utilization. Propensity scores were used to control for confounding. A generalized estimating equations (GEE) model using a gamma distribution and log link was used to determine the adjusted hospital cost and length of stay for the IV iron and ESA and ESA alone therapy groups. Results: During the study period, 82,947 patients met all the inclusion and exclusion criteria. Of the 82,947 CKD patients on ESA therapy, only 8% (n = 6678) patients were on IV iron supplementation. Age, race, primary payer, admission status, severity of illness, dialysis status and physician specialty were identified as strong predictors of IV iron use in CKD patients. According to the multivariate model, the overall mean hospital cost for all 82,947 patients was $31,674. For patients using both IV iron and ESA (n=6678), mean costs were $34,756 compared to $31,404 for ESA users alone (n=76,269) – a difference of $3,352. The overall mean LOS for all patients was 9.75 days. For those using IV iron, the LOS was 10.71 days, and for those only using ESA, the LOS was 9.66 days– a difference of approximately 1 day. Conclusions: This inquiry is the first large multi-center investigation to quantify the impact of IV iron and ESA use on total hospital costs and LOS. Our investigation showed significant reduction in ESA doses with the use of IV iron supplementation, however, the overall prevalence of IV iron usage was low. Intravenous iron users were associated with a higher total hospital cost and longer length of stay than ESA users.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

October 2010

Share

COinS