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Activity Number:
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141
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Type:
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Contributed
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Date/Time:
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Monday, August 7, 2006 : 10:30 AM to 12:20 PM
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Sponsor:
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Biometrics Section
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| Abstract - #306621 |
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Title:
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Use of a Marginal Structural Model To Estimate the Causal Effect of Epoetin Use on Hemactocrit Value among Hemodialysis Patients
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Author(s):
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Yi Zhang*+ and Mae Thamer and Dennis J. Cotter and James Kaufman and Miguel A. Hernán
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Companies:
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Medical Technology and Practice Patterns Institute and Medical Technology and Practice Patterns Institute and Medical Technology and Practice Patterns Institute and U.S. Department of Veterans Affairs and Harvard School of Public Health
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Address:
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4733 Bethesda Ave., #510, Bethesda, MD, 20814,
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Keywords:
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causal inference ; marginal structural model ; inverse probability of treatment weighted estimation ; erythropoietion ; hematocrit
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Abstract:
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Standard methods to adjust for time-varying confounders that are affected by previous treatment may lead to biased estimates. Marginal structural models (MSMs), introduced by Robins, can appropriately control for this type of time-dependent confounding. The parameters of MSMs are estimated by inverse probability weighting. We present an application of MSMs to estimate the causal effect of erythropoietin (EPO) on hemactocrit (Hct) response among renal failure patients with anemia. The research question is motivated by the discrepancies between observational and clinical trial results examining EPO treatment to ameliorate anemia. Specifically, in contrast to clinical trials, observational studies have reported a significantly inverse association between EPO and Hct.
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