Physical Sciences and Mathematics Commons^™

Correction Of Verication Bias Using Log-Linear Models For A Single Binaryscale Diagnostic Tests, Haresh Rochani, Hani M. Samawi, Robert L. Vogel, Jingjing Yin

Biostatistics Faculty Publications

In diagnostic medicine, the test that determines the true disease status without an error is referred to as the gold standard. Even when a gold standard exists, it is extremely difficult to verify each patient due to the issues of costeffectiveness and invasive nature of the procedures. In practice some of the patients with test results are not selected for verification of the disease status which results in verification bias for diagnostic tests. The ability of the diagnostic test to correctly identify the patients with and without the disease can be evaluated by measures such as sensitivity, specificity and predictive …

Estimated Probability Of Becoming Alcohol Dependent: Extending A Multiparametric Approach, Olga A. Vsevolozhskaya, James C. Anthony

Biostatistics Presentations

Background: United States (US) epidemiological studies suggest that for every 5-8 who start drinking alcoholic beverages, at least one drinker will develop an alcohol dependence (AD) syndrome within the first 10 years after onset of drinking (Lopez-Quintero et al., 2011; Wagner & Anthony, 2002). Recently, we described a multiparametric functional analysis approach for new research to estimate these transition probabilities with a one-dimensional function (1D; Vsevolozhskaya & Anthony, 2015). Here, we demonstrate extension of this analysis to two-dimensional (2D) functions that combine information about number of recent drinking days and number of drinks on the typical drinking day.

Methods: Data …

High Prevalence And Genetic Heterogeneity Of Rodent-Borne Bartonella Species On Heixiazi Island, China, Dong-Mei Li, Yong Hou, Xiu-Ping Song, Ying-Qun Fu, Gui-Chang Li, Ming Li, Marina E. Eremeeva, Hai-Xia Wu, Bo Pang, Yu-Juan Yue, Ying Huang, Liang Lu, Jun Wang, Qi-Yong Liu

Environmental Health Sciences Faculty Publications

We performed genetic analysis of Bartonella isolates from rodent populations from Heixiazi Island in northeast China. Animals were captured at four sites representing grassland and brushwood habitats in 2011 and examined for the prevalence and genetic diversity of Bartonella species, their relationship to their hosts, and geographic distribution. A high prevalence (57.7%) and a high diversity (14 unique genotypes which belonged to 8 clades) of Bartonella spp. were detected from 71 rodents comprising 5 species and 4 genera from 3 rodent families. Forty-one Bartonella isolates were recovered and identified, including B. taylorii, B. japonica, B. coopersplainsensis, B. grahamii, B. washoensis …

Sports Broadcasting News Analysis [Career Paper], Jefferson Sanders

Undergraduate Research Award

No abstract provided.

How To Start A Movement: Ted Talk Annotated Resource List, Daulton Cowan

Undergraduate Research Award

No abstract provided.

Nursing: The Career That Saves Lives [Career Paper], Maggie Flanagan

Undergraduate Research Award

No abstract provided.

Factors Impacting Transgender Patients’ Discomfort With Their Family Physicians: A Respondent-Driven Sampling Survey, Greta R. Bauer, Xuchen Zong, Ayden I. Scheim, Rebecca Hammond, Amardeep Thind

Epidemiology and Biostatistics Publications

BACKGROUND: Representing approximately 0.5% of the population, transgender (trans) persons in Canada depend on family physicians for both general and transition-related care. However, physicians receive little to no training on this patient population, and trans patients are often profoundly uncomfortable and may avoid health care. This study examined factors associated with patient discomfort discussing trans health issues with a family physician in Ontario, Canada.

METHODS: 433 trans people age 16 and over were surveyed using respondent-driven sampling for the Trans PULSE Project; 356 had a family physician. Weighted logistic regression models were fit to produce prevalence risk ratios (PRRs) via …

Monitoring For Adverse Events Post Marketing Approval Of Drugs, Karl E. Peace, Macaulay Okwuokenye

Biostatistics Faculty Publications

This brief communication provides information to those developing monitoring plans for serious adverse events (SAE’s) following regulatory approval of a new drug. In addition, we (1) illustrate how many patients would need to be treated in order to have high confidence of seeing at least 1 pre-specified SAE, (2) show that absence of proof of a SAE is not proof of absence of that SAE, and (3) identify statistical methodology that could be used for formal statistical monitoring of SAE’s.

Nested Partially-Latent, Class Models For Dependent Binary Data, Estimating Disease Etiology, Zhenke Wu, Maria Deloria-Knoll, Scott L. Zeger

Johns Hopkins University, Dept. of Biostatistics Working Papers

The Pneumonia Etiology Research for Child Health (PERCH) study seeks to use modern measurement technology to infer the causes of pneumonia for which gold-standard evidence is unavailable. The paper describes a latent variable model designed to infer from case-control data the etiology distribution for the population of cases, and for an individual case given his or her measurements. We assume each observation is drawn from a mixture model for which each component represents one cause or disease class. The model addresses a major limitation of the traditional latent class approach by taking account of residual dependence among multivariate binary outcome …

Identification And Survival Outcomes Of A Cohort Of Patients With Cancer Of Unknown Primary In Ontario, Canada., Chong S Kim, Malek B Hannouf, Sisira Sarma, George B Rodrigues, Peter K Rogan, Salaheddin M Mahmud, Eric Winquist, Muriel Brackstone, Gregory S Zaric

Epidemiology and Biostatistics Publications

BACKGROUND: Cancer of unknown primary origin (CUP) is defined by the presence of pathologically identified metastatic disease without clinical or radiological evidence of a primary tumour. Our objective was to identify incident cases of CUP in Ontario, Canada, and determine the influence of histology and sites of metastases on overall survival (OS).

MATERIAL AND METHODS: We used the Ontario Cancer Registry (OCR) and the Same-Day Surgery and Discharge Abstract Database (SDS/DAD) to identify patients diagnosed with CUP in Ontario between 1 January 2000, and 31 December 2005. Patient diagnostic information, including histology and survival data, was obtained from the OCR. …

'At-Risk' Places: Inequaties In The Distribution Of Environmental Stressors And Prescription Rates Of Mental Health Medications In Glasgow, Scotland, Juliana A. Maantay, Andrew Maroko

Publications and Research

Using geospatial analytical methods, this study examines the association between one aspect of the built environment, namely, the concentration of vacant and derelict land (VDL), and the prevalence of mental health disorders (using the proxy variable of mental health medication prescription rates) in Glasgow, Scotland. This study builds on our previous research, which demonstrated the spatial correspondence between the locations of VDL in Glasgow and several physical health outcomes. Numerous studies of other locales have found similar correspondence between different elements of the built environment and various health outcomes. This is the first study of its kind to look at …

Dynapenic Obesity And The Effect On Long-Term Physical Function And Quality Of Life: Data From The Osteoarthritis Initiative, John A. Batsis, Alicia J. Zbehlik, Dawna Pidgeon, Stephen J. Bartels

Dartmouth Scholarship

Obesity is associated with functional impairment, institutionalization, and increased mortality risk in elders. Dynapenia is defined as reduced muscle strength and is a known independent predictor of adverse events and disability. The synergy between dynapenia and obesity leads to worse outcomes than either independently. We identified the impact of dynapenic obesity in a cohort at risk for and with knee osteoarthritis on function.

Validation Of A New Predictive Risk Model: Measuring The Impact Of The Major Modifiable Risks Of Death For Patients And Populations, Stephen S. Lim, Emily Carnahan, Eugene C. Nelson, Catherine W. Gillespie, Ali H. Mokdad, Christopher J. L. Murray, Elliott S. Fisher

Dartmouth Scholarship

Background: Modifiable risks account for a large fraction of disease and death, but clinicians and patients lack tools to identify high risk populations or compare the possible benefit of different interventions.

Methods: We used data on the distribution of exposure to 12 major behavioral and biometric risk factors inthe US population, mortality rates by cause, and estimates of the proportional hazards of risk factor exposure from published systematic reviews to develop a risk prediction model that estimates an adult's 10 year mortality risk compared to a population with optimum risk factors. We compared predicted risk to observed mortality in 8,241 …

Depression, Obesity, And Metabolic Syndrome: Prevalence And Risks Of Comorbidity In A Population-Based Study Of Mexican Americans, Rene L. Olvera, Douglas E. Williamson, Susan P. Fisher-Hoch, Kristina Vatcheva, Joseph B. Mccormick

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

Introduction: We examined the prevalence of depression, obesity, and metabolic syndrome and associations between them in a population-based representative cohort of Mexican Americans living on the United States-Mexico border.

Method: The sample in this cross-sectional analysis consisted of 1,768 Mexican American adults (≥ 18 years of age) assessed between the years 2004 and 2010, with whom we tested our central hypothesis of a significant relationship between obesity and depression. Depression was measured using the Center for Epidemiologic Studies-Depression scale (CES-D) with a cutoff score of ≥ 16 for depression and a cutoff score of ≥ 27 for severe depression. We …

A Comparison Of A Multistate Inpatient Ehr Database To The Hcup Nationwide Inpatient Sample., Jonathan P Deshazo, Mark A Hoffman

Manuscripts, Articles, Book Chapters and Other Papers

BACKGROUND: The growing availability of electronic health records (EHRs) in the US could provide researchers with a more detailed and clinically relevant alternative to using claims-based data.

METHODS: In this study we compared a very large EHR database (Health Facts©) to a well-established population estimate (Nationwide Inpatient Sample). Weighted comparisons were made using t-value and relative difference over diagnoses and procedures for the year 2010.

RESULTS: The two databases have a similar distribution pattern across all data elements, with 24 of 50 data elements being statistically similar between the two data sources. In general, differences that were found are consistent …

Preparedness Of Hospitals In The Republic Of Ireland For An Influenza Pandemic, An Infection Control Perspective, Mary Reidy, Fiona Ryan, Dervla Hogan, Seán Lacey, Claire Buckley

Department of Mathematics Publications

When an influenza pandemic occurs most of the population is susceptible and attack rates can range as high as 40–50 %. The most important failure in pandemic planning is the lack of standards or guidelines regarding what it means to be ‘prepared’. The aim of this study was to assess the preparedness of acute hospitals in the Republic of Ireland for an influenza pandemic from an infection control perspective.

Household Bush Burning Practice And Related Respiratory Symptoms In Grenada, The Caribbean, Muge Akpinar-Elci, Kareem Coomansingh, James Blando, Larissa Mark

Center for Global Health Publications

The practice of household bush burning in Grenada occurs frequently, though it is not well documented. The effects of the emissions from bush burning on respiratory health of the population have never been researched in Grenada. The goal of the study was to measure the frequency of bush burning and to investigate the relationship between bush burning practice and respiratory health in Grenada. In this cross-sectional study, a questionnaire was used to gather information from households in the parishes of St. George and St. Andrew, Grenada. In total, 225 participants were recruited and their responses on household bush burning and …

Extended Followup Of A Cohort Of Chromium Production Workers, Herman Jones Gibb, Peter St. John Lees, Jing Wang, Keri O'Leary

Epidemiology Faculty Publications

Background

The current study evaluates the mortality of 2,354 workers first employed at a Baltimore chromate production plant between 1950 and 1974.

Methods

The National Death Index (NDI Plus) was used to determine vital status and cause of death. Cumulative chromium (VI) exposure and nasal and skin irritation were evaluated as risk factors for lung cancer mortality.

Results

There are 91,186 person-years of observation and 217 lung cancer deaths. Cumulative chromium (VI) exposure, nasal irritation, nasal perforation, nasal ulceration, and other forms of irritation (e.g., skin irritation) were associated with lung cancer mortality.

Conclusion

Cumulative chromium (VI) exposure was a …

Sexual Networks And Hiv Risk Among Black Men Who Have Sex With Men In 6 U.S. Cities, Hong-Van Tieu, Ting-Yuan Liu, Sophia Hussen, Matthew Connor, Lei Wang, Gregory Phillips Ii, + 11 More

Epidemiology Faculty Publications

Background

Sexual networks may place U.S. Black men who have sex with men (MSM) at increased HIV risk.

Methods

Self-reported egocentric sexual network data from the prior six months were collected from 1,349 community-recruited Black MSM in HPTN 061, a multi-component HIV prevention intervention feasibility study. Sexual network composition, size, and density (extent to which members are having sex with one another) were compared by self-reported HIV serostatus and age of the men. GEE models assessed network and other factors associated with having a Black sex partner, having a partner with at least two age category difference (age difference between …

Degradation Science: Mesoscopic Evolution And Temporal Analytics Of Photovoltaic Energy Materials, Roger H. French, Rudolf Podgornik, Timothy J. Peshek, Laura S. Bruckman, Yifan Xu, Nicholas R. Wheeler, Abdulkerim Gok, Yang Hu, Mohammad A. Hossain, Devin A. Gordon, Pei Zhao, Jiayang Sun, Guo-Qiang Zhang

Faculty Scholarship

Based on recent advances in nanoscience, data science and the availability of massive real-world datastreams, the mesoscopic evolution of mesoscopic energy materials can now be more fully studied. The temporal evolution is vastly complex in time and length scales and is fundamentally challenging to scientific understanding of degradation mechanisms and pathways responsible for energy materials evolution over lifetime. We propose a paradigm shift towards mesoscopic evolution modeling, based on physical and statistical models, that would integrate laboratory studies and real-world massive datastreams into a stress/mechanism/response framework with predictive capabilities. These epidemiological studies encompass the variability in properties that affect performance …

Caffeine Consumption Contributes To Skin Intrinsic Fluorescence In Type 1 Diabetes., Karen M Eny, Trevor J Orchard, Rachel Grace Miller, John Maynard, Denis M Grant, Tina Costacou, Patricia A. Cleary, Barbara H Braffett, Andrew D Paterson, Dcct/Edic Research Group

GW Biostatistics Center

Background: A variant (rs1495741) in the gene for the N-acetyltransferase 2 (NAT2) protein is associated with skin intrinsic fluorescence (SIF), a noninvasive measure of advanced glycation end products and other fluorophores in the skin. Because NAT2 is involved in caffeine metabolism, we aimed to determine whether caffeine consumption is associated with SIF and whether rs1495741 is associated with SIF independently of caffeine.

Materials and Methods: SIF was measured in 1,181 participants with type 1 diabetes from the Epidemiology of Diabetes Interventions and Complications study. Two measures of SIF were used: SIF1, using a 375-nm excitation light-emitting diode (LED), and …

Nitrate And Nitrite Ingestion And Risk Of Ovarian Cancer Among Postmenopausal Women In Iowa, Maki Inoue-Choi, Rena R. Jones, Kristin E. Anderson, Kenneth P. Cantor, James R. Cerhan, Stuart Krasner, Kimberly Robien, Peter J. Weyer, Mary H. Ward

Epidemiology Faculty Publications

Nitrate and nitrite are precursors in the endogenous formation of N-nitroso compounds (NOC), potential human carcinogens. We evaluated the association of nitrate and nitrite ingestion with postmenopausal ovarian cancer risk in the Iowa Women's Health Study. Among 28,555 postmenopausal women, we identified 315 incident epithelial ovarian cancers from 1986 to 2010. Dietary nitrate and nitrite intakes were assessed at baseline using food frequency questionnaire data. Drinking water source at home was obtained in a 1989 follow-up survey. Nitrate-nitrogen (NO₃-N) and total trihalomethane (TTHM) levels for Iowa public water utilities were linked to residences and average levels were …

Modification Of Traffic-Related Respiratory Response By Asthma Control In A Population Of Car Commuters, Maria C. Mirabelli, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Fernando Holguin, Priya Kewada, Andrea Winquist, W Dana Flanders, Jeremy A. Sarnat

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Background: Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status.

Methods: Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in …

Size And Power Of Tests Of Hypotheses On Survival Parameters From The Lindley Distribution With Covariates, Macaulay Okwuokenye, Karl E. Peace

Biostatistics Faculty Publications

The Lindley model is considered as an alternative model facilitating analyses of time-to-event data with covariates. Covariate information is incorporated using the Cox’s proportional hazard model with the Lindley model at the timedependent component. Simulation studies are performed to assess the size and power of tests of hypotheses on parameters arising from maximum likelihood estimators of parameters in the Lindley model. Results are contrasted with that arising from Cox’s partial maximum likelihood estimator. The Linley model is used to analyze a publicly available data set and contrasted with other models.

Joint Modeling Of Treatment Effect On Time-To-Event Endpoint And Safety Covariates In Control Clinical Trial Data Analysis, Kao-Tai Tsai, Karl E. Peace

Biostatistics Faculty Publications

It is a common practice to perform a separate analysis of efficacy and safety data from clinical trials to estimate the benefit and risk aspects of a particular treatment regimen. However, by doing so, one is likely to miss the complete picture of the treatment effect given that these data are generated from the same study subjects and therefore most likely will be correlated. Therefore, it is desirable to analyze these data jointly to obtain a more complete profile of the treatment regimen. A substantial number of statistical methodologies have been proposed in the last decade to model the time-to-event …

A General Framework For Diagnosing Confounding Of Time-Varying And Other Joint Exposures, John W. Jackson

Harvard University Biostatistics Working Paper Series

No abstract provided.

Adolescent Girls, Human Rights And The Expanding Climate Emergency, Holly G. Atkinson, Judith Bruce

Publications and Research

Many adolescent girls—the poorest girls in the poorest communities—already live in an “emergency.” Humanitarian crises only amplify the call on their coping and caring capacities, while exacerbating their vulnerabilities. The frequency and intensity of emergencies, including natural disasters, conflicts, and infectious disease outbreaks such as Ebola, appear to be growing.¹ These emergencies threaten entire communities and whole countries, often with global implications. Many become virtually permanent. The authors urge key actors responding to both the threats and opportunities that climate change poses to understand adolescent girls as exceptionally at risk on the one hand, and as exceptionally resilient and …

Industrial Production Manager [Career Paper], Wesley Osborne

Undergraduate Research Award

No abstract provided.

Statement And Action Agenda From The Girls In Emergencies Collaborative, Omar Robles, Judith Bruce, Holly G. Atkinson, Dale Buscher, Karen Scriven, Kristin Kim Bart, Shelby French, Judithe Registre, Audrey Anderson

Publications and Research

Many adolescent girls—the poorest girls in the poorest communities—already live in an “emergency.” Humanitarian crises only amplify the call on their coping and caring capacities, while exacerbating their vulnerabilities. The frequency and intensity of emergencies, including natural disasters, conflicts, and infectious disease outbreaks such as Ebola, appear to be growing. These emergencies threaten entire communities and whole countries, often with global implications. Many become virtually permanent.

The Happy Secret To Better Work: Ted Talk Annotated Resource List, Logan Secrest

Undergraduate Research Award

No abstract provided.