Epidemiology Commons^™

Targeted Methods For Biomarker Discovery, The Search For A Standard, Catherine Tuglus, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

More often than not biomarker studies analyze large quantities of variables with complicated and generally unknown correlation structure. There are numerous statistical methods which attempt to unravel these variables and determine the underlying mechanism through identification of causally related biomarkers. Results from these methods are generally difficult to interpret and nearly impossible to compare across studies. The FDA has currently called for a standardization of methods and protocol for biomarker detection. In response, we propose targeted variable importance (tVIM) as a standardized method for biomarker discovery. Through the use of targeted Maximum Likelihood, tVIM provides double robust estimates of variable …

Marginal Structural Models For Partial Exposure Regimes, Stijn Vansteelandt, Karl Mertens, Carl Suetens, Els Goetghebeur

Harvard University Biostatistics Working Paper Series

Intensive care unit (ICU) patients are ell known to be highly susceptible for nosocomial (i.e. hospital-acquired) infections due to their poor health and many invasive therapeutic treatments. The effects of acquiring such infections in ICU on mortality are however ill understood. Our goal is to quantify these effects using data from the National Surveillance Study of Nosocomial Infections in Intensive Care

Units (Belgium). This is a challenging problem because of the presence of time-dependent confounders (such as exposure to mechanical ventilation)which lie on the causal path from infection to mortality. Standard statistical analyses may be severely misleading in such settings …

Model Selection And Health Effect Estimation In Environmental Epidemiology, Francesca Dominici, Chi Wang, Ciprian Crainiceanu, Giovanni Parmigiani

Johns Hopkins University, Dept. of Biostatistics Working Papers

In air pollution epidemiology, improvements in statistical analysis tools can translate into significant scientific advances, because of the unfavorable signal-to-noise ratios, and large correlations between exposures and confounders. Therefore, the use of a novel model selection approach in identifying time windows of exposure to pollutants that lead to adverse health effects is important and welcome. However, previous literature has raised concerns about approaches that select a model based on a given data set, and then estimate health effects in the same data assuming that the chosen model is correct. Problems can be particularly severe when: 1) the sample size is …

Estimation Of Controlled Direct Effects, Sylvie Goetgeluk, Stijn Vansteelandt, Els Goetghebeur

Harvard University Biostatistics Working Paper Series

No abstract provided.

Foreign-Body Reaction Mimicking Postneurosurgical Infection After Cranioplasty, David Brett-Major, Sean M. Baraniak, Jonathan E. Gilhooly, Rebecca L. Christensen, Gerald T. Grant, Rocco A. Armonda, Anuradha Ganesan

Journal Articles: Epidemiology

The case of a 57-year-old woman who suffered a fall is presented. After a polymethyl malacrylate revision cranioplasty, she presented with signs, symptoms, and intraoperative findings consistent with postneurosurgical infection. Dural foreign-body reaction was diagnosed, and parenteral antibiotic therapy was discontinued successfully.

Suicides Among Farmers In Three Southeastern States, 1990-1998, Steven R. Browning, Susan C. Westneat, Robert H. Mcknight

Epidemiology and Environmental Health Faculty Publications

Several studies have documented higher rates of suicide among farmers in comparison to other occupational groups, both in the U.S. and internationally. The purpose of this study is to describe the epidemiology of farmer suicides in three southeastern states (Kentucky, North Carolina, and South Carolina) during the nine-year period 1990-1998. Electronic death certificate data were obtained from the National Center for Health Statistics. Over the nine-year period, there were 590 deaths related to suicide (E-codes: 950-959) among farmers (occupation codes: 473, 474, 475, 477, and 479) in the states of Kentucky, North Carolina, and South Carolina. The results of this …

A Spatial Sirs Boolean Network Model For The Spread Of H5n1 Avian Influenza Virus Among Poultry Farms, Alexander Kasyanov, Leona Kirkland, Mihaela Teodora Matache

Mathematics Faculty Proceedings & Presentations

To predict the spread of Avian Influenza we propose a synchronous Susceptible-Infected-Recovered-Susceptible (SIRS) Boolean network of poultry farms, using probabilistic Boolean rules. Gravity models from transportation theory are used for the probability of infection of a node in one time step, taking into account farm sizes, distances be- tween farms, and mean distance travelled by birds. Basic reproduction numbers are computed analytically and numerically. The dynamics of the network are analyzed and various statistics considered such as number of infected nodes or time until eradication of the epidemic. We conclude that mostly when large farms (eventually) become infected the epidemic …

Assessment Of Seminary Education On End Of Life Issues, Stefan Hakon Pomrenke

Theses and Dissertations

Background: The US health care system faces increased costs from end of life (EOL) care. The intensive approach to EOL treatment with greater use of procedures in ICUs has led to decedent spending six times greater than that of survivors in the hospital. Experts in ICU and Palliative care fields have called for greater utilization of end of life planning and education. To date, EOL education has been dominated by the technologically driven medical field and the church has been under-utilized. The US population relies on clergy support for many mental health and EOL issues. Clergy report feeling uncomfortable in …

Prognostic Factors Of Varying Treatment Outcomes For Onychomycosis (Nail Fungal Infection) Patients, Bin Cai

Walden Dissertations and Doctoral Studies

Prevalence of onychomycosis, as high as 26.9% in the general population, can be reduced by improving current antifungal treatment. This could be accomplished by understanding prognostic factors, especially healthy nail growth, associated with achieving complete cure. This population-based study aimed to evaluate if healthy nail length or percentage of total full nail length as healthy can be early indictors for complete cure. Logistics regression analyses were performed by comparing variables between a population who achieved the complete cure and a population who failed after both populations received the same antifungal treatment in two large randomized double-blinded clinical trials that assessed …