Physical Sciences and Mathematics Commons^™

Flexible Distributed Lag Models Using Random Functions With Application To Estimating Mortality Displacement From Heat-Related Deaths, Roger D. Peng

Johns Hopkins University, Dept. of Biostatistics Working Papers

No abstract provided.

Adjusting Medicare Capitation Payments Using Prior Hospitalization Data, Arlene Ash, Frank Porell, Leonard Gruenberg, Eric Sawitz, Alexa Beiser

Frank Porell

The diagnostic cost group approach to a reimbursement model for health maintenance organizations is presented. Diagnostic information about previous hospitalizations is used to create empirically determined risk groups, using only diagnoses involving little or no discretion in the decision to hospitalize. Diagnostic cost group and other models (including Medicare's current formula and other prior-use models) are tested for their ability to predict future costs, using R2 values and new measures of predictive performance. The diagnostic cost group models perform relatively well with respect to a range of criteria, including administrative feasibility, resistance to provider manipulation, and statistical accuracy.

Geographic Disparities Associated With Stroke And Myocardial Infarction In East Tennessee, Ashley Pedigo Golden

Doctoral Dissertations

Stroke and myocardial infarction (MI) are serious conditions whose burdens vary by socio-demographic and geographic factors. Although several studies have investigated and identified disparities in burdens of these conditions at the county and state levels, little is known regarding their geographic epidemiology at the neighborhood level. Both conditions require emergency treatments and therefore timely geographic accessibility to appropriate care is critical. Investigation of disparities in geographic accessibility to stroke and MI care and the role of Emergency Medical Services (EMS) in reducing treatment delays are vital in improving health outcomes. Therefore, the objectives of this work were to: (i) classify …

Exploration And Comparison Of Methods For Combining Population- And Family-Based Genetic Association Using The Genetic Analysis Workshop 17 Mini-Exome, David W. Fardo, Anthony R. Druen, Jinze Liu, Lucia Mirea, Claire Infante-Rivard, Patrick Breheny

Biostatistics Faculty Publications

We examine the performance of various methods for combining family- and population-based genetic association data. Several approaches have been proposed for situations in which information is collected from both a subset of unrelated subjects and a subset of family members. Analyzing these samples separately is known to be inefficient, and it is important to determine the scenarios for which differing methods perform well. Others have investigated this question; however, no extensive simulations have been conducted, nor have these methods been applied to mini-exome-style data such as that provided by Genetic Analysis Workshop 17. We quantify the empirical power and false-positive …

Assessing Association For Bivariate Survival Data With Interval Sampling: A Copula Model Approach With Application To Aids Study, Hong Zhu, Mei-Cheng Wang

Johns Hopkins University, Dept. of Biostatistics Working Papers

In disease surveillance systems or registries, bivariate survival data are typically collected under interval sampling. It refers to a situation when entry into a registry is at the time of the first failure event (e.g., HIV infection) within a calendar time interval, the time of the initiating event (e.g., birth) is retrospectively identified for all the cases in the registry, and subsequently the second failure event (e.g., death) is observed during the follow-up. Sampling bias is induced due to the selection process that the data are collected conditioning on the first failure event occurs within a time interval. Consequently, the …

Clinically Optimal Dosing In The Treatment Of Duodenal Ulcers: A Case Study Of A Phase Iii Snda Clinical Program, Karl E. Peace

Biostatistics Faculty Publications

Georgia Southern University faculty member Karl E. Peace authored "Case Study in Optimal Dosing in Duodenal Eulcer" in Peptic Ulcer Disease.

A Bayesian Model For Gene Family Evolution, Liang Liu, Lili Yu, Venugopal Kalavacharla, Zhanji Liu

Biostatistics Faculty Publications

Background

A birth and death process is frequently used for modeling the size of a gene family that may vary along the branches of a phylogenetic tree. Under the birth and death model, maximum likelihood methods have been developed to estimate the birth and death rate and the sizes of ancient gene families (numbers of gene copies at the internodes of the phylogenetic tree). This paper aims to provide a Bayesian approach for estimating parameters in the birth and death model.

Results

We develop a Bayesian approach for estimating the birth and death rate and other parameters in the birth …

Depicting Estimates Using The Intercept In Meta-Regression Models: The Moving Constant Technique, Blair T. Johnson Dr., Tania B. Huedo-Medina Dr.

CHIP Documents

In any scientific discipline, the ability to portray research patterns graphically often aids greatly in interpreting a phenomenon. In part to depict phenomena, the statistics and capabilities of meta-analytic models have grown increasingly sophisticated. Accordingly, this article details how to move the constant in weighted meta-analysis regression models (viz. “meta-regression”) to illuminate the patterns in such models across a range of complexities. Although it is commonly ignored in practice, the constant (or intercept) in such models can be indispensible when it is not relegated to its usual static role. The moving constant technique makes possible estimates and confidence intervals at …

Heterogeneity And Data Analysis, Peter J. Taylor

Working Papers on Science in a Changing World

This working paper is a discussion paper for a September 2011 meeting of the research group of Prof. Di Cook on data visualization and exploratory data analysis at Iowa State University. A taxonomy of eleven kinds of heterogeneity is presented, followed by a set of vignettes that illustrate some of the meanings and sketch some implications, then a series of images that illustrate the heterogeneities. Several of the vignettes speak to a broad contention about heterogeneity and control: In relation to modern understandings of heredity and development over the life course, research and application of resulting knowledge are untroubled by …

A Regularization Corrected Score Method For Nonlinear Regression Models With Covariate Error, David M. Zucker, Malka Gorfine, Yi Li, Donna Spiegelman

Harvard University Biostatistics Working Paper Series

No abstract provided.

Social Networks Enabled Coordination Model For Cost Management Of Patient Hospital Admissions, Shahadat Uddin, Liaquat Hossain

Shahadat Uddin

In this study, we introduce a social networks enabled coordination model for exploring the effect of network position of “patient,” “physician,” and “hospital” actors in a patient-centered care network that evolves during patient hospitalization period on the total cost of coordination. An actor is a node, which represents an entity such as individual and organization in a social network. In our analysis of actor networks and coordination in the healthcare literature, we identified that there is significant gap where a number of promising hospital coordination model have been developed (e.g., Guided Care Model, Chronic Care Model) for the current healthcare …

When Is Informed Consent Required In Cluster Randomized Trials In Health Research?, Andrew Mcrae, Charles Weijer, Ariella Binik, Jeremy Grimshaw, Robert Boruch, Jamie Brehaut, Allan Donner, Martin P Eccles, Raphael Saginur, Angela White, Monica Taljaard

Charles Weijer

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the cluster trial is to be set on a firm ethical foundation. This paper addresses the second of the questions posed, namely, from whom, when, and how must informed consent be obtained in CRTs in health research? The ethical principle of respect for persons implies that researchers are generally obligated to obtain the informed consent of research subjects. Aspects of CRT …

Advancing Stage Of Female Reproductive Life Associated With Bipolar Illness Exacerbation, Wendy K. Marsh, Terence Ketter, Sybil L. Crawford, Julia V. Johnson, Anthony J. Rothschild

Sybil L. Crawford

Introduction: Perimenopause confers an increased risk of depression in the general population, yet bipolar disorder mood course remains unknown. Methods: Clinic visits in 519 premenopausal, 116 perimenopausal including 13 women transitioning from peri- to postmenopause, and 133 postmenopausal women with bipolar disorder who received naturalistic treatment in the multisite STEP-Bipolar Disorder study over 19.8 +/- 15.5 months were analyzed for mood state. Results: Advancing female reproductive stage was associated with significant decline in mood elevation; significant decline in euthymia; no significant difference in major depression; and symptomatic significant increase. Conclusions: Advancing stage of female reproductive life was associated with bipolar …

Use Of Optimal Control Models To Predict Treatment Time For Managing Tick-Borne Disease, Holly D. Gaff, Elsa Schaefer, Suzanne Lenhart

Biological Sciences Faculty Publications

Tick-borne diseases have been on the rise recently, and correspondingly, there is an increased interest in implementing control measures to decrease the risk. Optimal control provides an ideal tool to identify the best method for reducing risk while accounting for the associated costs. Using a previously published model, a variety of frameworks are assessed to identify the key factors influencing mitigation strategies. The level and duration of tick-reducing efforts are key metrics for understanding the successful reduction in tick-borne disease incidence. The results show that the punctuated nature of the tick's life history plays a critical role in reducing risk …

Thirdhand Tobacco Smoke: Emerging Evidence And Arguments For A Multidisciplinary Research Agenda, Georg E. Matt, Penelope J. Quintana, Hugo Destaillats, Lara A. Gundel, Mohamad Sleiman, Brett C. Singer, Peyton Jacob, Jonathan P. Winickoff, Prue Talbot, Suzaynn Schick, Yinsheng Wang, Bo Hang, Manuela Martins-Green, James F. Pankow, Melbourne F. Hovell, Neal L. Benowitz, Virender K. Rehan, Jonathan M. Samet

Civil and Environmental Engineering Faculty Publications and Presentations

There is broad consensus regarding the health impact of tobacco use and secondhand smoke exposure, yet considerable ambiguity exists about the nature and consequences of thirdhand smoke (THS). We introduce definitions of THS and THS exposure and review recent findings about constituents, indoor sorption-desorption dynamics, and transformations of THS; distribution and persistence of THS in residential settings; implications for pathways of exposure; potential clinical significance and health effects; and behavioral and policy issues that affect and are affected by THS. Physical and chemical transformations of tobacco smoke pollutants take place over time scales ranging from seconds to months and include …

An Occupational-Based Experimental Study Of Collective Vs. Personal Efficacy To Encourage Sun Protective Behaviors In Head Start Preschool Teachers, Elizabeth A. Holzhauser

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Skin cancer is one of the most common types of cancers in the United States. An analysis of literature shows that skin cancer can be partially mitigated through personal behavior changes (Glanz, Buller, & Saraiya; 2007, Canadian Centre of Occupational Health and Safety [CCOHS], 2010). Currently national sun-safety educational campaigns promote sun-protective behaviors to individuals who receive exposure due to their work environment (Task Force on Community Preventive Services, 2004). Preschool teachers employed with San Bernardino County Head Start are inadvertently exposed to sunlight during mandatory recess periods posing risks to their health.

Purpose. This study evaluated two instructional …

Assessment Of Organic And Inorganic Phosphorus In Soils Derived From Cretaceous Sediments And Basement Complex Soils Of Guinea Savannah Of Kogi State, North Central Nigeria, Sunday I. Amhakhian, H H. Isitekhale, Charles I. Oyewole

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

A pot experiment was carried out using 20 surface soils (0-15cm depth) in 2008 to assess soil organic phosphorus and some fraction of inorganic phosphorus in other to know their availability in the soils of the studied area and also work have not been done in this areas in respect to organic and in-organic phosphorus. The experiment was conducted using 20 soils 10 from each geological formation (Cretaceous sediments and Basement complex soils), respectively. The mean organic phosphorus of 63.51 mgkg 1 soil was obtained for Cretaceous sediment soils and 158.54 mgkg 1 soil for the basement complex soils respectively. …

Development Of Functional Indices Of Facility Occurrence Towards The Distribution Of Social Services In Lagos Island Nigeria., Augustus O. Atubi

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

Proper coordination of transport and public facilities provision is vital to any balanced regional development strategy. The central aim of this study, therefore, is to find out what the relationship is between access to the transport network and the provision of functional indices of facility occurrence towards the distribution of social services in Lagos Island, Nigeria. In particular it seeks to find out areas that have below or above average level of facility occurrences relative to the level of accessibility. However, a pair wise correlation matrix of the eleven (11) variables employed in the index construction was carried out. The …

Development Of Dose Conversion Coefficients For Radionuclides Produced In Spallation Neutron Sources, Phillip W. Patton

Transmutation Sciences Physics (TRP)

A research consortium comprised of representatives from several universities and national laboratories will be established as part of this project to generate internal and external dose conversion coefficients for radionuclides produced in spallation neutron sources. Information obtained from this multi-year study will be used to support the siting and licensing of future accelerator-driven nuclear initiatives within the U.S. Department of Energy complex, including the Spallation Neutron Source (SNS) and Accelerator Production of Tritium (APT) projects. Determination of these coefficients will also fill data gaps for several hundred radionuclides that exist in Federal Guidance Report (FGR) No. 11 and in Publications …

The Use Of Chloramines To Eradicate Quagga Mussel Larvae, Trea Lacroix, Kumud Acharya

Undergraduate Research Opportunities Program (UROP)

Quagga Mussels, Dressenia bugensis, are a growing problem in the western United States, particularly in their ability to infest underwater infrastructures and clog water intake pipes and screens of power and treatment plants. Chlorine has been found to be the most effective chemical to get rid of veligers (planktonic larval form of quagga mussels) in the pipes. However, chlorine leaves a residue called trihalomethane, which is a carcinogen at higher concentrations. The purpose of this project is to test the effectiveness of an alternate chemical, chloramines (chlorine and ammonia), which leaves behind little to no residual trihalomethane. Upon experimentation with …

A Geospatial Based Decision Framework For Extending Marssim Regulatory Principles Into The Subsurface, Robert Nathan Stewart

Doctoral Dissertations

The Multi-Agency Radiological Site Survey Investigation Manual (MARSSIM) is a regulatory guidance document regarding compliance evaluation of radiologically contaminated soils and buildings (USNRC, 2000). Compliance is determined by comparing radiological measurements to established limits using a combination of hypothesis testing and scanning measurements. Scanning allows investigators to identify localized pockets of contamination missed during sampling and allows investigators to assess radiological exposure at different spatial scales. Scale is important in radiological dose assessment as regulatory limits can vary with the size of the contaminated area and sites are often evaluated at more than one scale (USNRC, 2000). Unfortunately, scanning is …

Perceived Parent-Child Relationship And High-Risk Behaviors Among Christian College Students, Karla G. Lavin Williams

Loma Linda University Electronic Theses, Dissertations & Projects

Background. Adolescents and young adults today are participating in high-risk behaviors such as dangerous sexual behaviors and drug and alcohol abuse at high rates. An increased incidence of negative effects associated with the aforementioned behaviors has led researchers to examine factors that influence and protect adolescents from certain devastating effects (Davis, Hendershot, George, Norris, & Heiman, 2007; Goldstein, Bamett, Pedlow, & Murphy, 2007; Hamilton, et al., 2007; Hingson, Heeren, & Winter, 2006; Hingson, Heeren, Winter, & Wechsler, 2003; Hingson, Heeren, Zakocs, Winter, & Wechsler, 2003; McCarty, et al., 2004; Mokdad, Marks, Stroup, & Gerberding, 2004; Mosher, Chandra, & Jones, 2005; …

Impact Of An Online Support System On Health Related Quality Of Life Among Men Diagnosed With Prostate Cancer, Daniel K. Osei

Loma Linda University Electronic Theses, Dissertations & Projects

Prostate cancer is a major public health issue worldwide and a significant cause of male cancer death in the USA. Though early screening and treatment has greatly enhanced the outcome, men diagnosed with prostate cancer face problems that compromise quality of life after treatment. Online support for prostate cancer clients is a convenient way to help because it is anonymous, inexpensive, and can be used at clients’ convenience. Yet few studies have explored how these supports impact these clients. This study used a longitudinal randomized experimental design to examine the impact of online services on quality of life of prostate …

A Comparison Of Spatio-Temporal Prediction Methods Of Cancer Incidence In The U.S, Michelle Hamlyn

UNLV Theses, Dissertations, Professional Papers, and Capstones

Cancer is the cause of one out of four deaths in the United States, and in 2009, researchers expected over 1.5 million new patients to be diagnosed with some form of cancer. People diagnosed with cancer, whether a common or rare type, need to undergo treatments, the amount and kind of which will depend on the severity of the cancer. So how do healthcare providers know how much funding is needed for treatment? What would better enable a pharmaceutical company to determine how much to allocate for research and development of drugs, the amount of each drug to manufacture, or …

Gene By Bmi Interactions Influencing C-Reactive Protein Levels In European-Americans, Sarah Tudor

Dissertations & Theses (Open Access)

C-Reactive Protein (CRP) is a biomarker indicating tissue damage, inflammation, and infection. High-sensitivity CRP (hsCRP) is an emerging biomarker often used to estimate an individual’s risk for future coronary heart disease (CHD). hsCRP levels falling below 1.00 mg/l indicate a low risk for developing CHD, levels ranging between 1.00 mg/l and 3.00 mg/l indicate an elevated risk, and levels exceeding 3.00 mg/l indicate high risk. Multiple Genome-Wide Association Studies (GWAS) have identified a number of genetic polymorphisms which influence CRP levels. SNPs implicated in such studies have been found in or near genes of interest including: CRP, APOE, APOC, IL-6, …

Heterogeneity, Control, Social Infrastructure, And Possibilities Of Participation: Their Interplay In Modern Understandings Of Heredity And In Interpretation Of Science, Peter J. Taylor

Working Papers on Science in a Changing World

This working paper is a prospectus for research, writing, and engagement. It consists of vignettes, sketches of lines of inquiry, and proposals for engagement, all of which concern modern understandings of heredity and development over the life course as well as the social interpretation of science. The various items address a range of areas of science and of its interpretation: heritability studies, the social uses of genetic information, gene-by-environment interaction, personalized medicine, IQ paradoxes, racial group membership, biobanks, and life events and difficulties research. Fresh perspectives in these areas are opened up by examining the ways that research and application …

Identifying Unique Neighborhood Characteristics To Guide Health Planning For Stroke And Heart Attack: Fuzzy Cluster And Discriminant Analyses Approaches, Ashley Pedigo, William Seaver, Agricola Odoi

Agricola Odoi

Background: Socioeconomic, demographic, and geographic factors are known determinants of stroke and myocardial infarction (MI) risk. Clustering of these factors in neighborhoods needs to be taken into consideration during planning, prioritization and implementation of health programs intended to reduce disparities. Given the complex and multidimensional nature of these factors, multivariate methods are needed to identify neighborhood clusters of these determinants so as to better understand the unique neighborhood profiles. This information is critical for evidence-based health planning and service provision. Therefore, this study used a robust multivariate approach to classify neighborhoods and identify their socio-demographic characteristics so as to provide …

Who Is The Research Subject In Cluster Randomized Trials In Health Research?, Andrew Mcrae, Charles Weijer, Ariella Binik, Angela White, Jeremy Grimshaw, Robert Boruch, Jamie Brehaut, Allan Donner, Martin Eccles, Raphael Saginur, Merrick Zwarenstein, Monica Taljaard

Charles Weijer

This article is part of a series of papers examining ethical issues in cluster randomized trials (CRTs) in health research. In the introductory paper in this series, we set out six areas of inquiry that must be addressed if the CRT is to be set on a firm ethical foundation. This paper addresses the first of the questions posed, namely, who is the research subject in a CRT in health research? The identification of human research subjects is logically prior to the application of protections as set out in research ethics and regulation. Aspects of CRT design, including the fact …

Assessing Medicare Beneficiaries’ Strength‐Of‐Preference Scores For Health Care Options: How Engaging Does The Elicitation Technique Need To Be?, Trafford Crump, Hilary A. Llewellyn-Thomas

Dartmouth Scholarship

The objective was to determine if participants’ strength‐of‐preference scores for elective health care interventions at the end‐of‐life (EOL) elicited using a non‐engaging technique are affected by their prior use of an engaging elicitation technique.

Urban Climate And Challenges Of Tropical Cities, B E. Omogbai

Confluence Journal Environmental Studies (CJES), Kogi State University, Nigeria

This study examines the nature of urban climate, features and the challenges on the developing tropical cities in the 21st century. It argues that the use of principles of urban climate would help in providing comfortable living conditions and problem immune working environments for the inhabitants of tropical cities. The findings reveal that owing to poor environmental planning, inadequate geotechnical landscape surveys prior to the development of urban infrastructures, and non-adherence to the principles of urban climate, challenges of landscape degradation, excessive flooding of the built infrastructures, heat-island effects, and collapse of buildings have emerged. Suggested measures to avert these …