Epidemiology Commons^™

Estimating Effects By Combining Instrumental Variables With Case-Control Designs: The Role Of Principal Stratification, Russell T. Shinohara, Constantine E. Frangakis, Elizabeth Platz, Konstantinos Tsilidis

Johns Hopkins University, Dept. of Biostatistics Working Papers

The instrumental variable framework is commonly used in the estimation of causal effects from cohort samples. In the case of more efficient designs such as the case-control study, however, the combination of the instrumental variable and complex sampling designs requires new methodological consideration. As the prevalence of Mendelian randomization studies is increasing and the cost of genotyping and expression data can be high, the analysis of data gathered from more cost-effective sampling designs is of prime interest. We show that the standard instrumental variable analysis is not applicable to the case-control design and can lead to erroneous estimation and inference. …

Impact Of Ambient Air Pollution On Survival Of Renal Transplant Recipients, Rhonda Kristine Hwang

Loma Linda University Electronic Theses, Dissertations & Projects

There is increasing evidence that ambient air pollution is associated with coronary heart disease morbidity and mortality. This research has focused on the general public and less so on possible sensitive subgroups even though these may have even greater susceptibility to adverse effects of ambient air pollution. With highly prevalent traditional as well as nontraditional risk factors, renal transplant recipients may potentially be a sensitive subgroup. The purpose of this study was to evaluate the possible effect of between long-term exposure to air pollution on the risk of CHD mortality among renal transplant recipients. This cohort study includes 32,239 adult, …

Pengaruh Kemiskinan Keluarga Pada Kejadian Pneumonia Balita Di Indonesia, Rizanda Machmud

Kesmas

Pneumonia merupakan penyakit infeksi saluran pernapasan akut yang menjadi kausa utama kematian balita. Di Indonesia, pada akhir tahun 2000, angka kematian balita akibat pneumonia diperkirakan 4,9/1000 balita. Faktor sosio-ekonomi berkontribusi besar terhadap penyakit saluran pernapasan. Tujuan penelitian ini adalah mengetahui faktor sosio-ekonomi yang paling berpengaruh terhadap pneumonia pada balita. Penelitian dengan dengan disain krosseksional ini menggunakan sumber data sekunder Benefit Evaluation Study (BES) II oleh Pusat Penelitian Kesehatan Universitas Indonesia bekerja sama dengan Proyek Intensifikasi Pemberantasan Penyakit Menular, Departemen Kesehatan. Sampel diambil berdasarkan multilevel statistical frameworkdari 7.170 ba-lita pada 10.900 rumah tangga di 27 kabupaten di tujuh provinsi. Metode analisis …

Makanan Etnik Minahasa Dan Kejadian Penyakit Jantung Koroner, Grace Debbie Kandou

Kesmas

Penyakit jantung koroner yang menjadi kausa utama kematian di seluruh dunia merupakan masalah kesehatan masyarakat yang penting di seluruh dunia, termasuk Indonesia dan Sulawesi Utara. Kebiasaan makan yang dipengaruhi oleh faktor budaya, adat istiadat, agama dan kepercayaan berperan penting dalam proses kejadian penyakit. Penelitian ini bertujuan mengetahui pengaruh kebiasaan makan etnik Minahasa terhadap kejadian penyakit jantung koroner. Penelitian di RSU Prof. Dr. R.D. Kandou ini menggunakan disain studi kasus kontrol dengan ukuran sampel 128 kasus dan 128 kontrol. Data frekuensi makan dikumpulkan dengan Food Frequency Quationnaire (FFQ). Makanan etnik Minahasa ditentukan berdasarkan 41 jenis makanan yang dikompositkan. Asam lemak jenuh …

The Effects Of Physical Activity And Nutrient Intake On The Risk Of Hip Fracture : Results From The Adventist Health Study-2, Wen-Ling Liao

Loma Linda University Electronic Theses, Dissertations & Projects

This is a two year of follow up study of Adventist Health Study-2 (AHS-2). We assessed the association between physical activity, nutrient intake and risk of hip fracture among peri- and post menopausal Caucasian women using unconditional logistic regression models. All subjects completed a lifestyle questionnaire which including information of physical activity and frequency and portion size of food intake at enrollment into the study (2002-2007). The “Bi-Annual Hospitalization History” questionnaire which included a question about hip fractures due to minor trauma/falls was sent to subjects approximately two years after enrollment, with a response rat of 82.84%. In this cohort, …

Complexity, Cofactors, And The Failure Of Aids Policy In Africa, Eileen Stillwaggon

Economics Faculty Publications

Global AIDS policy still treats HIV as an exceptional case, abstracting from the context in which infection occurs. Policy is based on a simplistic theory of HIV causation, and evaluated using outdated tools of health economics. Recent calls for a health systems strategy – preventing and treating HIV within a programme of comprehensive health care – have not yet influenced the silo approach of AIDS policy.

Evidence continues to accumulate, showing that multiple factors, such as malnutrition, malaria and helminthes, increase the risk of sexual and vertical transmission of HIV. Moreover, complementary interventions that reduce viral load, improve immune response, …

Situasi Malaria Di Kabupaten Lebak, Fauzul Hayat, Nia Kurniatillah

Kesmas

Pada periode 2002-2006, di Kabupaten Lebak, API tergolong Middle Case Incidence (MCI), dengan nilai rata-rata (2.87%) dan berada pada kisaran 2.04-4.51%. Dari 35 wilayah kerja puskesmas terdapat enam wilayah endemis yang meliputi puskesmas Malimping, Binuangeun, Bayah, Cihara, Panggarangan dan Cilograng. Ada wilayah kerja puskesmas yang dilaporkan dengan klasifikasi MCI. Penderita positif malaria cenderung meningkat secara fluktuatif dengan puncak yang tidak jelas, kasus positif malaria tertingi ditemukan pada bulan Februari, Maret, Mei, Juli dan Desember. Tingkat infeksi malaria yang tinggi pada kelompok populasi ditentukan berdasarkan proporsi sediaan darah positif malaria dari sediaan darah yang diperiksa dengan angka SPR 006 rata-rata 12.64%, …

A Spatio-Temporal Approach For Estimating Chronic Effects Of Air Pollution, Sonja Greven, Francesca Dominici, Scott L. Zeger

Johns Hopkins University, Dept. of Biostatistics Working Papers

Estimating the health risks associated with air pollution exposure is of great importance in public health. In air pollution epidemiology, two study designs have been used mainly. Time series studies estimate acute risk associated with short-term exposure. They compare day-to-day variation of pollution concentrations and mortality rates, and have been criticized for potential confounding by time-varying covariates. Cohort studies estimate chronic effects associated with long-term exposure. They compare long-term average pollution concentrations and time-to-death across cities, and have been criticized for potential confounding by individual risk factors or city-level characteristics.

We propose a new study design and a statistical model, …

Spatial Cluster Detection For Repeatedly Measured Outcomes While Accounting For Residential History, Andrea J. Cook, Diane Gold, Yi Li

Harvard University Biostatistics Working Paper Series

No abstract provided.

Spatial Cluster Detection For Weighted Outcomes Using Cumulative Geographic Residuals, Andrea J. Cook, Yi Li, David Arterburn, Ram C. Tiwari

Harvard University Biostatistics Working Paper Series

No abstract provided.

A Machine-Learning Algorithm For Estimating And Ranking The Impact Of Environmental Risk Factors In Exploratory Epidemiological Studies, Jessica G. Young, Alan E. Hubbard, B Eskenazi, Nicholas P. Jewell

U.C. Berkeley Division of Biostatistics Working Paper Series

No abstract provided.

Tuberculosis In San Bernardino County, 1993-2004 : Lifestyle And Environmental Factors, Anuj Bhatia

Loma Linda University Electronic Theses, Dissertations & Projects

An observational retrospective study was conducted for tuberculosis (TB) cases between San Bernardino County (SBC), Riverside County, and the state of California from 1996 to 2004. A univariate comparison between San Bernardino County and California indicated a higher proportion of U.S. born cases in SBC. Additionally, it was found that San Bernardino had a higher proportion of non-injection drug using TB cases, compared with California in 1996. Further comparisons were made along country of birth between TB cases in San Bernardino County from 1993 to 2004. Notable differences were observed for injection drug use, non injection drug use, alcohol abuse, …

Anthropometric Parameters Of Under-Five Years Old Children With Different Dietary Habits In Ukambani Region : A Study In Eastern Rural Kenya, Hellen M. Ndiku

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of this descriptive cross sectional study was to assess dietary intake and nutritional status of children under-five years in two rural sites of Eastern Kenya where the staple cereals may differ. A modified rapid, knowledge, practice and coverage (KPC) questionnaire and a 24-hr dietary recall form were used to collect the data. A total of 403 households were surveyed from four randomly selected divisions. This yielded 629 surrogate 24-hr dietary recalls of children < 5 years with 314 from Mwingi district and 315 from Makueni district (49 % boys and 51 % girls).

Statistical analysis was done using SPSS and SAS. Comparison of means was done using t- test and chi square was used for proportions. The 24-hr …

Modeling And Analysis Of The Spread Of Japanese Encephalitis With Environmental Effects, Ram Naresh, Surabhi Pandey

Applications and Applied Mathematics: An International Journal (AAM)

A nonlinear mathematical model for the spread of Japanese Encephalitis, caused by infected mosquito feeding on susceptible human population incorporating demographic and environmental factors is proposed and analyzed. In the modeling process, it is assumed that the growth rates of reservoir animal population and vector mosquito population are enhanced due to environmental discharges caused by human population related factors. The model is analyzed by stability theory of differential equations and computer simulation. Both the disease-free and the endemic equilibria are found and their stability is investigated. It is found that whenever the disease-free equilibrium is locally asymptotically stable, the endemic …

Is Volunteering During Adolescence Associated With A Delay In Pregnancy Until Adulthood?, Diane Bishop

Theses and Dissertations

Purpose: The objective of this study was to determine if regular volunteering during adolescence was associated with a delay in first pregnancy until adulthood. Method: Data for this analysis were drawn from Wave III of the National Longitudinal Study of Adolescent Health (Add Health). Logistic regression was used, controlling for demographic characteristics and pregnancy intention, to estimate the independent contribution of volunteering during adolescence to a delay in first pregnancy until after age 18. Results: One-third of respondents reported regularly volunteering during adolescence. Volunteering significantly differed among those who had a teen pregnancy compared to those who delayed pregnancy until …

Patients Evaluated For Liver Transplant: Transplant List Denial And Subsequent Outcomes, Kara Elam

Theses and Dissertations

Background: The evaluation process for listing a patient on the liver transplant list is complicated and involves multiple consultations from various specialists, as well as extensive imaging and physiological studies. Although there are data on the outcomes of those listed, we know little about those that are denied listing. This research project will identify the reasons for liver transplant listing denial and predictors of death following denial for this challenging group of patients. Methods: Data from all patients (n=1,500) evaluated for a liver transplant from 1997 to 2007 by the Department of Gastroenterology, Hepatology, and Nutrition located at Virginia Commonwealth …

Physical Activity Among Diabetic Individuals According To Diabetic Treatment Type, Tammie Thompson

Theses and Dissertations

Purpose: To evaluate the physical activity patterns of diabetic adults by the type of treatment they received Method: The study used secondary data collected by the National Health and Nutrition Examination Survey (NHANES) from 2001 to 2006. NHANES is a continuous study which measures the health and nutritional status of non-institutionalized citizens in the United States. To be eligible for the study, participants had to be an adult 18 years or older who responded during the interview phase of the survey that they had diabetes. Participants with any missing data pertaining to the variables were excluded. After exclusions, the final …

Determinants Of Hepatitis B Vaccination Among Adults In The United States: Nhanes 1999-2006, Conschetta Wright

Theses and Dissertations

Purpose: The primary objective of this study was to estimate the prevalence of vaccination and HBV infection status of adults and to evaluate the trend in self reported vaccination and seroprevalence for Hepatitis B for this population. Additionally, this study sought to assess the association between vaccination rates, seroprevalence (HBsAg, anti-HBc, and anti-HBs), demographic (age, gender, location of birth, race/ethnicity), and socioeconomic (annual household income, education level, insurance coverage and access to care, marital status) characteristics. Methods: Eight years, 1999-2006, of the National Health and Nutrition Examination Survey (NHANES) data were used. NHANES participants aged 20-59 years who contributed data …

Does Unemployment Decrease Cancer Mortality?, Benjamin Torres Galick

Economics Honors Projects

Recent research indicates that healthier lifestyles during recessions decrease the most common U.S. mortalities, but not cancer. However, they combine specific cancer mortalities with different progressions into one, possibly obscuring cancer’s link to unemployment. This paper estimates a fixed-effects regression model on unemployment and the nine most prevalent cancers between 1988 and 2002 using state-level panel data. Five cancers and total cancer are procyclical, and suggest that unemployment affects both incidence and gestation for some cancers. Consistent with the medical literature, this paper contradicts previous economic research and suggests that behavioral factors significantly impact cancer mortality.

Relationship Between Parental Role-Modeling Of Physical Activity And Child's Physical Activity, Katherine Culver

Theses and Dissertations

Trends in childhood obesity have lead to a generation that has a shortened lifespan, where excessive weight may decrease life expectancy by as much as five years. Physical inactivity is a major risk factor for childhood obesity as well as cardiovascular disease, osteoporosis, and cancer. Addressing inactivity in children could help keep the obesity epidemic from continuing to grow as well as help address other health concerns. The specific aims of this study are 1) To examine the effect of parental role-modeling of exercise on children’s activity level by specifically looking at the role of the mother and the father, …

History Of Pregnancy Termination As A Risk Factor For Preterm Birth, Virginia 2000-20007, Jennifer Macdonald

Theses and Dissertations

Abstract Objectives: The objective of this study was to determine if an association exists between prior induced and prior spontaneous pregnancy termination (PIPT and PSPT) and preterm birth (PTB) of first live births in Virginia. Methods: Data was collected by linking maternal data from Virginia’s live birth and fetal death registries. All first live, singleton births occurring in Virginia from 2000-2007 were analyzed. Logistic regression models that controlled for various demographic, medical and obstetric history factors were used to determine associations among prior pregnancy termination types. Results: Compared with women who had no history of previous pregnancy terminations, women who …

Evaluation Of The Program Delivery Of Every Women's Life In Virginia, Landolt Susan Kenney

Theses and Dissertations

Introduction: Among women, breast cancer is the most prevalent cancer and the second leading cause of cancer death. Although technology advances have improved survival rates for breast cancer overall, improvements have not been universally experienced by all socioeconomic and racial groups. Known determinants of breast cancer care disparities include socioeconomic status, race, age, and social support. As a part of the Breast and Cervical Cancer Mortality Prevention Act of 1990 and with the help of CDC funding, the Virginia Breast and Cervical Cancer Early Detection Program (BCCEDP) or Every Woman’s Life (EWL) was created. EWL provides breast cancer screening to …

A Culturally-Relevant, Emergent Approach To Exploring The Needs, Strengths, And Priorities Of Tribal Communities In Virginia, Amy Prorock-Ernest

Theses and Dissertations

Little is known about the health of the indigenous peoples in Virginia. When compared to the total U.S. population, indigenous peoples nationwide disproportionately experience disparities in health status across multiple health indicators. Research shows that these disparities are largely due to the inequitable distribution of social and economic determinants present within indigenous communities. Because the indigenous peoples of Virginia are affected by inequitable social and economic conditions, there is reason to believe that health indicators may mirror that of the indigenous population at-large. Outlined in this paper is a framework for exploring the needs, strengths, and priorities of indigenous communities …

Molecular Epidemiology Of Methicillin-Resistant Staphylococcus Aureus (Mrsa), Ilene Bautista

UNLV Theses, Dissertations, Professional Papers, and Capstones

Staphylococcus aureus is a frequent cause of a myriad of infections in hospitals, healthcare facilities and community settings. It is often related to skin and soft tissue infection, but it can also cause other diseases varying from food poisoning to endocarditis and toxic shock syndrome. According to a study by Kuehnert et al. (2006) there has been a strong association between Staphylococcus aureus (S. aureus) carriage and risk factors for subsequent infections. Subsequent infection from S. aureus , including methicillin-resistant S. aureus (MRSA) infection, can be projected by looking at the presence of S. aureus nasal colonization. The purpose of …

Delayed And Forgone Care For Children With Special Health Care Needs In Virginia: A Cross-Sectional Study Using 2005-2006 Ns-Cshcn, Nevena Skoro

Theses and Dissertations

Objectives The objectives of our study were to: 1) summarize illness characteristics and functional ability difficulties among Children With Special Health Care Needs (CSHCN) in Virginia, 2) examine the distribution of socio-demographic, health insurance, and health-related factors among Virginia’s CSHCN, 3) quantify the influence of these socio-demographic, health insurance, and health-related factors on delayed and forgone care of CSHNC in Virginia, and 4) analyze reasons for delayed and forgone care among Virginia’s CSHCN. Methods Data from the 2005-2006 National Survey of Children with Special Health Care Needs (NS-CSHCN) were used for this study. Three categories of predictor variables were studied: …

Weight Perception And The Use Of Unhealthy Weight Loss Tactics Among Adults In The United States: A Cross-Sectional Study Of Nhanes Data, 2000-2006., Laura King

Theses and Dissertations

Introduction: Weight dissatisfaction and misperception are widespread problems in the United States as are unhealthy weight loss practices. These negative body image issues can lead to eating disorders which have serious health and quality of life consequences. Objective: To evaluate the extent to which the prevalence of distorted body image and unhealthy dieting tactics exist in adults in the US and how these are related. Methods: Data from NHANES 2000-20006 on adults aged 20-59 was used. Weight perception was assessed with the physical exam measurements of weight status and the weight history questionnaire item asking if the person considered him …

Perception Of Power Dynamics And Risky Sexual Behavior In Indian Men, Amber Haley

Theses and Dissertations

Background: Women account for about a third of all new cases of HIV in India. Based on research examining trends of HIV infection in women, male perception and behaviors have emerged as strong potential risk factors. However, there has been limited research examining the relationship between male’s attitudes toward women and their sexual risk-taking behaviors. This study examined the degree to which men’s beliefs about power dynamics in heterosexual relationships are related to risky sexual behaviors in Indian men. Methods: Data on Indian men from the 2005-2006 National Family Health Survey (NFHS-3) was analyzed (N= 44,727). The outcome variable, risky …

Meta-Analysis: Racial Disparities In Prostate Cancer Survival And Case-Control Study: Association Between Family History Of Cancers, Obesity And Prostate Cancer, Gayathri Sridhar

Theses and Dissertations

This is a compilation of 3 abstracts for the three manuscripts included in this dissertation. I. Meta-Analysis: Racial Disparities in Prostate Cancer Survival: Prostate cancer is the second leading cause of cancer-related mortality in men. Previous studies have drawn inconsistent conclusions on racial differences in prostate cancer survival. This meta-analysis was conducted to investigate the relationship between race and survival from prostate cancer. A systematic review of published articles from 1968 to 2007 assessing survival from prostate cancer among African American and White men was conducted. The search yielded 20 eligible published manuscripts. Analysis of unadjusted studies showed African American …

Hiv/Aids Di Indonesia : Fenomena Gunung Es Dan Peranan Pelayanan Kesehatan Primer, Hardisman Hardisman

Kesmas

Masalah HIV/AIDS di Indonesia diyakini bagaikan fenomena gunung es karena laporan resmi jumlah kasus tidak mencerminkan masalah yang sebenarnya. Prediksi besar masalah HIV/AIDS tersebut didasarkan atas jumlah penyalahgunaan narkotika suntik dan prostitusi yang tinggi. Keduanya merupakan faktor utama yang berperan sangat besar dalam penyebaran dan penularan HIV. Berbagai faktor risiko tersebut tidak hanya berkaitan dengan pelayanan keseha-tan tetapi juga dengan masalah sosial ekonomi. Permasalahan tersebut perlu diatasi dengan pendekatan pelayanan kesehatan primer komprehensif yang langsung menyentuh akar permasalahan mencakup masalah sosial ekonomi dan lingkungan kultural. Strategi tersebut dilakukan melalui berbagai langkah yang bersifat menyeluruh, meliputi preventif, promotif, kuratif dan rehabilitatif …

Physical Activity Levels Of Older Community-Dwelling Adults Are Influenced By Summer Weather Variables, Caitlin A. Brandon, Dawn P. Gill, Mark Speechley, Jason Gilliland, Gareth R. Jones

Geography & Environment Publications

Adequate daily physical activity (PA) is important for maintaining functional capacity and independence in older adults. However, most older adults in Canada do not engage in enough PA to sustain fitness and functional independence. Environmental influences, such as warmer daytime temperatures, may influence PA participation; however, few studies have examined the effect of summertime temperatures on PA levels in older adults. This investigation measured the influence of summertime weather variables on PA in 48 community-dwelling older adults who were randomly recruited from a local seniors’ community centre. Each participant wore an accelerometer for a single 7-consecutive-day period (between 30 May …