Epidemiology Commons^™

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.

Estimation Of Risk Ratios In Cohort Studies With Common Outcomes: A Simple And Efficient Two-Stage Approach, Eric J. Tchetgen

Harvard University Biostatistics Working Paper Series

No abstract provided.

On The Nondifferential Misclassification Of A Binary Confounder, Elizabeth L. Ogburn, Tyler J. Vanderweele

COBRA Preprint Series

Abstract Consider a study with binary exposure, outcome, and confounder, where the confounder is nondifferentially misclassified. Epidemiologists have long accepted the unproven but oft-cited result that, if the confounder is binary, odds ratios, risk ratios, and risk differences which control for the mismeasured confounder will lie between the crude and the true measures. In this paper the authors provide an analytic proof of the result in the absence of a qualitative interaction between treatment and confounder, and demonstrate via counterexample that the result need not hold when there is a qualitative interaction between treatment and confounder. They also present an …

Hiv And Concurrent Sexual Partnerships: Modelling The Role Of Coital Dilution, Larry Sawers, Alan G. Isaac, Eileen Stillwaggon

Economics Faculty Publications

Background: The concurrency hypothesis asserts that high prevalence of overlapping sexual partnerships explains extraordinarily high HIV levels in sub-Saharan Africa. Earlier simulation models show that the network effect of concurrency can increase HIV incidence, but those models do not account for the coital dilution effect (nonprimary partnerships have lower coital frequency than primary partnerships).

Methods: We modify the model of Eaton et al (AIDS and Behavior, September 2010) to incorporate coital dilution by assigning lower coital frequencies to non-primary partnerships. We parameterize coital dilution based on the empirical work of Morris et al (PLoS ONE, December …

Modification By Frailty Status Of Ambient Air Pollution Effects On Lung Function In Older Adults In The Cardiovascular Health Study, Sandrah P. Eckel, Thomas A. Louis, Paulo H.M. Chaves, Linda P. Fried, Helene G. Margolis

Johns Hopkins University, Dept. of Biostatistics Working Papers

Older adult susceptibility to air pollution health effects is well-recognized. Advanced age may act as a partial surrogate for conditions associated with aging. The authors investigated whether gerontologic frailty (a clinical health status metric) modified the effects of ambient ozone or particulate matter (PM10) air pollution on lung function in 3382 older adults using 7 years of followup data from the Cardiovascular Health Study (CHS) and the CHS Environmental Factors Ancillary Study. Monthly average pollution and annual frailty assessments were related to up to 3 repeated measurements of lung function using novel cumulative summaries of pollution and frailty histories that …

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

Dissertations and 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, …

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 …

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 …

Variable Importance Analysis With The Multipim R Package, Stephan J. Ritter, Nicholas P. Jewell, Alan E. Hubbard

U.C. Berkeley Division of Biostatistics Working Paper Series

We describe the R package multiPIM, including statistical background, functionality and user options. The package is for variable importance analysis, and is meant primarily for analyzing data from exploratory epidemiological studies, though it could certainly be applied in other areas as well. The approach taken to variable importance comes from the causal inference field, and is different from approaches taken in other R packages. By default, multiPIM uses a double robust targeted maximum likelihood estimator (TMLE) of a parameter akin to the attributable risk. Several regression methods/machine learning algorithms are available for estimating the nuisance parameters of the models, including …

Reduced Bayesian Hierarchical Models: Estimating Health Effects Of Simultaneous Exposure To Multiple Pollutants, Jennifer F. Bobb, Francesca Dominici, Roger D. Peng

Johns Hopkins University, Dept. of Biostatistics Working Papers

Quantifying the health effects associated with simultaneous exposure to many air pollutants is now a research priority of the US EPA. Bayesian hierarchical models (BHM) have been extensively used in multisite time series studies of air pollution and health to estimate health effects of a single pollutant adjusted for potential confounding of other pollutants and other time-varying factors. However, when the scientific goal is to estimate the impacts of many pollutants jointly, a straightforward application of BHM is challenged by the need to specify a random-effect distribution on a high-dimensional vector of nuisance parameters, which often do not have an …

Characterization Of The Serologic Responses To Plasmodium Vivax Dbpii Variants Among Inhabitants Of Pursat Province, Cambodia, Samantha Jones Barnes

USF Tampa Graduate Theses and Dissertations

The Plasmodium vivax Duffy Binding Protein (DBP) is the ligand in the major pathway for P. vivax invasion of human reticulocytes, making it an appealing vaccine candidate. Region II of DBP (DBP-RII) is the minimal portion of the ligand that mediates recognition of the Duffy Antigen Receptor for Chemokines (DARC receptor) on the reticulocyte surface and constitutes the primary vaccine target. Analysis of natural variation in the coding sequences of DBP-RII revealed signature evidence for selective pressure driving variation in the residues of the putative receptor-binding site. We hypothesize that anti-DBP immunity in P. vivax infections is strain-specific and hindered …

Principal Component Analysis Of Dietary And Lifestyle Patterns In Relation To Risk Of Subtypes Of Esophageal And Gastric Cancer, Stephanie A. Navarro Silvera, Susan T. Mayne, Harvey A. Risch, Marilie D. Gammon, Thomas Vaughan, Wong-Ho Chow, Joel A. Dubin, Robert Dubrow, Janet Schoenberg, Janet L. Stanford, A. Brian West, Heidrun Rotterdam, William J. Blot

Department of Public Health Scholarship and Creative Works

Purpose

To carry out pattern analyses of dietary and lifestyle factors in relation to risk of esophageal and gastric cancers.

Methods

We evaluated risk factors for esophageal adenocarcinoma (EA),esophageal squamous cell carcinoma(ESCC), gastric cardia adenocarcinoma (GCA), and other gastric cancers (OGA) using data from a population-based case-control study conducted in Connecticut, New Jersey, and western Washington state. Dietary/lifestyle patterns were created using principal component analysis (PCA). The impact of the resultant scores on cancer risk was estimated through logistic regression.

Results

PCA identified six patterns: meat/nitrite, fruit/vegetable, smoking/alcohol, legume/meat alternate, GERD/BMI, and fish/vitamin C. Risk of each cancer under study …

Farmwork-Related Injury Among Farmers 50 Years Of Age And Older In Kentucky And South Carolina: A Cohort Study, 2002-2005, Jennifer L. Marcum, Steven R. Browning, Deborah B. Reed, Richard Charnigo

Epidemiology and Environmental Health Faculty Publications

Farmers in the U.S. are becoming more diverse; the average age of the farmer is increasing, as is the number of women and minority farm operators. There is limited research on injury risk factors in these special populations of farmers. It is especially important to study the risk factors for injury in these growing and at-risk groups. A longitudinal survey was conducted of farmers (n = 1,394) age 50 and older who resided in Kentucky and South Carolina. The questionnaire was administered by telephone and mail surveys four times between 2002 and 2005 to the fixed cohort of farmers, obtained …

Studi Kematian Ibu Dan Kematian Bayi Di Provinsi Sumatera Barat: Faktor Determinan Dan Masalahnya, Ulvi Mariati, Z Agus, D Sulin, Masrul Masrul, Z Amri, F Arasy, Muslim Muslim, H Hanum, Mohanis Mohanis, F Arma

Kesmas

Salah satu tujuan yang hendak dicapai oleh World Health Organization pada tahun 2000 adalah health for all by year 2000. Beberapa indikator digunakan untuk mengukur pencapaian tersebut, diantaranya angka kematian bayi (AKB) dan angka kematian ibu (AKI). Dinas Kesehatan Sumatera Barat telah berhasil menurunkan AKB dan AKI selama 5 tahun terakhir, akan tetapi angka-angka tersebut tidak menggambarkan angka yang sebenarnya karena hanya diperoleh berdasarkan prediksi perhitungan statistik kependudukan. Angka tersebut juga tidak dapat memperlihatkan disparitas antarwilayah dan kelompok sosial ekonomi di Sumatera Barat. Penelitian ini dilakukan untuk mendapatkan AKB dan AKI yang tepat serta mengetahui faktor determinan dan permasalahannya di …

Perbandingan Rapid Diagnostic Test Dan Pemeriksaan Mikroskopik Pada Diagnosis Malaria, Lombok Siahaan

Kesmas

Penelitian ini dilakukan untuk membandingkan penggunaan Rapid diagnostic test dengan pemeriksaan mikroskopik (apusan darah) dalam menegakkan diagnosis malaria. Penelitian uji diagnostik ini dilakukan di Kabupaten Nias Selatan dan Kotamadya Sabang, Sumatera Utara. Apusan darah diwarnai dengan larutan Giemsa 10% dan dibaca oleh pemeriksa yang sudah terlatih. Rapid diagnostic test dilakukan dengan menggunakan parascreen. Uji diagnostik rapid diagnostic test secara umum diperoleh hasil yaitu sensitivitas 63,8%; spesifisitas 100%; Positive Predictive Value (PPV) 100%; dan negative predictive value (NPV) 93,5%. Kepadatan parasit pada rapid diagnostic test (+) dan mikroskopik (+) adalah 1.483 ± 583 parasit/μl. Sementara, kepadatan parasit pada pemeriksaan rapid diagnostic …

Faktor Risiko Kanker Serviks Di Rumah Sakit Umum Pemerintah Dr. Wahidin Sudirohusodo Makassar, Sulawesi Selatan, Sri Syatriani

Kesmas

Kanker serviks adalah tumor ganas terbanyak pada perempuan di seluruh dunia termasuk Indonesia. Jumlah penderita kanker serviks di Rumah Sakit Umum Pemerintah Dr. Wahidin Sudirohusodo pada tahun 2007 sebanyak 231 kasus, menurun menjadi 220 kasus tahun 2008 dan menurun sebanyak 167 kasus pada tahun 2009. Tujuan penelitian ini adalah untuk melihat besar risiko kejadian kanker serviks terhadap penggunaan pembalut, penggunaan sabun, status ekonomi, dan pasangan pria yang tidak disirkumsisi. Jenis penelitian adalah penelitian observasional analitik dengan desain kasus kontrol. Sampel adalah pasien yang berkunjung ke bagian ginekologi yang diambil secara accidental sampling sebanyak 213 orang. Pengumpulan data dilakukan dengan wawancara …

Perflurorochemical (Pfc) Exposure In Children: Associations With Impaired Response Inhibition, Brooks B. Gump, Qian Wu, Amy K. Dumas, Kurunthachalam Kannan

Falk College Research Center

Background: Perfluorinated chemicals (PFCs) have been used widely in consumer products since the 1950s and are currently found at detectable levels in the blood of humans and animals across the globe. In stark contrast to this widespread exposure to PFCs, there is relatively little research on potential adverse health effects of exposure to these chemicals.Objectives: We performed this cross-sectional study to determine if specific blood PFC levels are associated with impaired response inhibition in children. Methods: Blood levels of 11 PFCs were measured in children (N = 83) and 6 PFCs: perfluorooctane sulfonate (PFOS), perfluorohexane sulfate (PFHxS), perfluorooctanoic acid (PFOA), …

Exploring Geographic Proximity To Fast-Food Restaurants And Convenience Stores With Dental Caries In Patients At The University Of Nevada Las Vegas School Of Dental Medicine, Charles K. Hill

UNLV Theses, Dissertations, Professional Papers, and Capstones

Dental caries is present worldwide and has afflicted over 90% of all adults in the United States. Biological determinants of the disease are well understood but social determinants and how they interact with biological factors are not. Programs designed to reduce incidence and prevalence of caries often target certain individuals and involve behavioral change. Some programs are more successful when environmental and societal issues are also addressed (Watt, 2002). Biological and behavioral processes leading to caries should include the modification of social factors to enhance results of prevention programs designed to reduce caries in populations. Preventing disease comes not only …

Modeling Mortality Rates For Leukemia Between Men And Women In The United States, Blessed Quansah

UNLV Theses, Dissertations, Professional Papers, and Capstones

Leukemia related deaths increased dramatically over the last forty years. Leukemia is a malignant disease or cancer of the bone marrow and blood. It is characterized by the uncontrolled accumulation of blood cells. Leukemia is divided into two categories: myelogenous or lymphocytic, each of which can be acute or chronic. The terms, myelogenous or lymphocytic denote the cell type involved.

In this thesis, the proposed modeling techniques are applied to leukemia deaths data from the Surveillance Epidemiology and End Results (SEER). In particular, annual deaths data from 1969 to 2007 are used in the data analysis, which includes three major …

Tuberkulosis Paru Di Palembang, Sumatera Selatan, Hery Unita Versitaria, Haryoto Kusnoputranto

Kesmas

Indonesia tercatat memiliki 304.787 penderita tuberkulosis yang menempatkannya pada peringkat ketiga terbanyak di dunia. Penyakit tuberkulosis merupakan penyebab kematian nomor 3 setelah penyakit kardiovaskuler dan penyakit saluran pernafasan pada semua kelompok usia serta nomor 1 dari golongan penyakit infeksi. Angka kepadatan hunian rumah di Kota Palembang 5,84 lebih tinggi daripada angka ideal kepadatan hunian rumah. Penelitian ini bertujuan mengetahui hubungan antara sumber penular serumah, faktor lingkungan dalam rumah, dan karakteristik individu terhadap kejadian tuberkulosis paru basil tahan asam (BTA) (+) di Kota Palembang. Penelitian yang menggunakan desain kasus kontrol ini membandingkan kelompok kasus (BTA(+)) dan kelompok kontrol (BTA (-)) yang …