David A. Marker
Westat
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Publication
Featured researches published by David A. Marker.
Science of The Total Environment | 2011
Nicole C. Deziel; Susan M. Viet; John Rogers; David Camann; David A. Marker; Maire S.A. Heikkinen; Alice Y. Yau; Daniel M. Stout; Michael Dellarco
Different wipe materials and wetting agents have been used to collect pesticide residues from surfaces, but little is known about their comparability. To inform the selection of a wipe for the National Childrens Study, the analytical feasibility, collection efficiency, and precision of Twillwipes wetted with isopropanol (TI), Ghost Wipes (GW), and Twillwipes wetted with water (TW), were evaluated. Wipe samples were collected from stainless steel surfaces spiked with high and low concentrations of 27 insecticides, including organochlorines, organophosphates, and pyrethroids. Samples were analyzed by GC/MS/SIM. No analytical interferences were observed for any of the wipes. The mean percent collection efficiencies across all pesticides for the TI, GW, and TW were 69.3%, 31.1%, and 10.3% at the high concentration, respectively, and 55.6%, 22.5%, and 6.9% at the low concentration, respectively. The collection efficiencies of the TI were significantly greater than that of GW or TW (p<0.0001). Collection efficiency also differed significantly by pesticide (p<0.0001) and spike concentration (p<0.0001). The pooled coefficients of variation (CVs) of the collection efficiencies for the TI, GW, and TW at high concentration were 0.08, 0.17, and 0.24, respectively. The pooled CV of the collection efficiencies for the TI, GW, and TW at low concentration were 0.15, 0.19, and 0.36, respectively. The TI had significantly lower CVs than either of the other two wipes (p=0.0008). Though the TI was superior in terms of both accuracy and precision, it requires multiple preparation steps, which could lead to operational challenges in a large-scale study.
Preventing Chronic Disease | 2017
Russ Mardon; David A. Marker; Jennifer Nooney; Joanne R. Campione; Frank Jenkins; Maurice Johnson; Lori Merrill; Deborah B. Rolka; Sharon Saydah; Linda S. Geiss; Xuanping Zhang; Sundar S. Shrestha
States bear substantial responsibility for addressing the rising rates of diabetes and prediabetes in the United States. However, accurate state-level estimates of diabetes and prediabetes prevalence that include undiagnosed cases have been impossible to produce with traditional sources of state-level data. Various new and nontraditional sources for estimating state-level prevalence are now available. These include surveys with expanded samples that can support state-level estimation in some states and administrative and clinical data from insurance claims and electronic health records. These sources pose methodologic challenges because they typically cover partial, sometimes nonrandom subpopulations; they do not always use the same measurements for all individuals; and they use different and limited sets of variables for case finding and adjustment. We present an approach for adjusting new and nontraditional data sources for diabetes surveillance that addresses these limitations, and we present the results of our proposed approach for 2 states (Alabama and California) as a proof of concept. The method reweights surveys and other data sources with population undercoverage to make them more representative of state populations, and it adjusts for nonrandom use of laboratory testing in clinically generated data sets. These enhanced diabetes and prediabetes prevalence estimates can be used to better understand the total burden of diabetes and prediabetes at the state level and to guide policies and programs designed to prevent and control these chronic diseases.
Statistics in Medicine | 2018
David A. Marker; Russ Mardon; Frank Jenkins; Joanne R Campione; Jennifer Nooney; Jane Li; Sharon Saydeh; Xuanping Zhang; Sundar S. Shrestha; Deborah B. Rolka
Many statisticians and policy researchers are interested in using data generated through the normal delivery of health care services, rather than carefully designed and implemented population-representative surveys, to estimate disease prevalence. These larger databases allow for the estimation of smaller geographies, for example, states, at potentially lower expense. However, these health care records frequently do not cover all of the population of interest and may not collect some covariates that are important for accurate estimation. In a recent paper, the authors have described how to adjust for the incomplete coverage of administrative claims data and electronic health records at the state or local level. This article illustrates how to adjust and combine multiple data sets, namely, national surveys, state-level surveys, claims data, and electronic health record data, to improve estimates of diabetes and prediabetes prevalence, along with the estimates of the methods accuracy. We demonstrate and validate the method using data from three jurisdictions (Alabama, California, and New York City). This method can be applied more generally to other areas and other data sources.
Environmental Health Perspectives | 2002
David E. Jacobs; Susan M. Viet; David A. Marker; John Rogers; Darryl C. Zeldin; Pamela Broene; Warren Friedman
Environmental Health Perspectives | 2002
Patrick J Vojta; Warren Friedman; David A. Marker; John Rogers; Susan M. Viet; Michael L. Muilenberg; Peter S. Thorne; Samuel J. Arbes; Darryl C. Zeldin
Environmetrics | 1999
Nicolle A. Mode; Loveday L. Conquest; David A. Marker
Social Science & Medicine | 2007
Jean Martin; David A. Marker
Environmetrics | 2002
Nicolle A. Mode; Loveday L. Conquest; David A. Marker
Journal of Environmental Health | 2013
Susan Marie Viet; John Rogers; David A. Marker; Alexa Fraser; Warren Friedman; David E. Jacobs; Nicolle S. Tulve
Contemporary Jewry | 2016
David A. Marker