Statistics and Probability Commons^™

Emergency Department Use Following Incentives To Provide After-Hours Primary Care: A Retrospective Cohort Study., Michael Hong, Amardeep Thind, Gregory S Zaric, Sisira Sarma

Epidemiology and Biostatistics Publications

BACKGROUND: Access to primary care outside of regular working hours is limited in many countries. This study investigates the relation between the after-hours premium, an incentive for primary care physicians to provide services after hours, and less-urgent visits to the emergency department in Ontario, Canada.

METHODS: We analyzed a retrospective cohort of a random sample of Ontario residents from April 2002 to March 2006, and a subcohort of patients followed from April 2005 to March 2016. We linked patient and primary care physician data with emergency department visit data. We used fixed-effects regression models to analyze the association between the …

Genetics Of Pediatric Musculoskeletal Disorders, Lilian Antunes

Arts & Sciences Electronic Theses and Dissertations

Pediatric musculoskeletal disorders are an extremely broad category of diseases that are often inherited. While individually rare, collectively these disorders are common, affecting around 3% of live births in the US. Despite the mounting clinical and molecular evidence for a genetic etiology, the cause for many patients with pediatric musculoskeletal disorders remain largely unknown. Major challenges in rare pediatric diseases include recruiting large numbers of patients and determining the significance and functional impacts of variants associated with disease within individuals or families. Whole exome sequencing (WES) is a powerful tool to identify coding variants that are associated with rare pediatric …

Machine Learning Morphisms: A Framework For Designing And Analyzing Machine Learning Work Ows, Applied To Separability, Error Bounds, And 30-Day Hospital Readmissions, Eric Zenon Cawi

McKelvey School of Engineering Theses & Dissertations

A machine learning workflow is the sequence of tasks necessary to implement a machine learning application, including data collection, preprocessing, feature engineering, exploratory analysis, and model training/selection. In this dissertation we propose the Machine Learning Morphism (MLM) as a mathematical framework to describe the tasks in a workflow. The MLM is a tuple consisting of: Input Space, Output Space, Learning Morphism, Parameter Prior, Empirical Risk Function. This contains the information necessary to learn the parameters of the learning morphism, which represents a workflow task. In chapter 1, we give a short review of typical tasks present in a workflow, as …

Sars-Cov-2 Pandemic Analytical Overview With Machine Learning Predictability, Anthony Tanaydin, Jingchen Liang, Daniel W. Engels

SMU Data Science Review

Understanding diagnostic tests and examining important features of novel coronavirus (COVID-19) infection are essential steps for controlling the current pandemic of 2020. In this paper, we study the relationship between clinical diagnosis and analytical features of patient blood panels from the US, Mexico, and Brazil. Our analysis confirms that among adults, the risk of severe illness from COVID-19 increases with pre-existing conditions such as diabetes and immunosuppression. Although more than eight months into pandemic, more data have become available to indicate that more young adults were getting infected. In addition, we expand on the definition of COVID-19 test and discuss …

Computing For Numeracy: How Safe Is Your Covid-19 Social Bubble?, Charles Connor

Numeracy

The COVID-19 pandemic has led many people to form social bubbles. These social bubbles are small groups of people who interact with one another but restrict interactions with the outside world. The assumption in forming social bubbles is that risk of infection and severe outcomes, like hospitalization, are reduced. How effective are social bubbles? A Bayesian event tree is developed to calculate the probabilities of specific outcomes, like hospitalization, using example rates of infection in the greater community and example prior functions describing the effectiveness of isolation by members of the social bubble. The probabilities are solved for two contrasting …

Review Of Social Workers Count: Numbers And Social Issues By Michael Anthony Lewis, Michael T. Catalano

Numeracy

Lewis, Michael Anthony. 2017. Social Workers Count: Numbers and Social Issues. 2019. New York: Oxford University Press. 223 pp. ISBN 978-019046713-5

The numeracy movement, although largely birthed within the mathematics community, is an outside-the-box endeavor which has always sought to break down or at least transgress traditional disciplinary boundaries. Michael Anthony Lewis’s book is a testament that this effort is succeeding. Lewis is a social worker and sociologist with an impressive resume, author of Economics for Social Workers, co-editor of The Ethics and Economics of the Basic Income Guarantee, and member of the faculty at the Silberman School …

Using Covid-19 Vaccine Efficacy Data To Teach One-Sample Hypothesis Testing, Frank Wang

Numeracy

In late November 2020, there was a flurry of media coverage of two companies’ claims of 95% efficacy rates of newly developed COVID-19 vaccines, but information about the confidence interval was not reported. This paper presents a way of teaching the concept of hypothesis testing and the construction of confidence intervals using numbers announced by the drug makers Pfizer and Moderna publicized by the media. Instead of a two-sample test or more complicated statistical models, we use the elementary one-proportion z-test to analyze the data. The method is designed to be accessible for students who have only taken a …

Covid-19 Pandemic In Brazil: Clinical Manifestation And Effect Of Comorbidities On Outcomes Of Hospitalized Sari Cases, Mario Keko, Karl E. Peace

Department of Biostatistics, Epidemiology, and Environmental Health Sciences Faculty Publications

Hospitalized SARI cases of 2020 reported to the Ministry of Health of Brazil through the SIVEP Gripe system are subject to our analysis. They are classified as COVID-19 and non-COVID-19 and clinical manifestations and comorbidities are reported for each group. The time trend in the number of cases reported in 2020 is compared to the previous year and the performance of the PCR test is explored in each group. The proportion of death is reported among different subgroups of the patients by epidemiological week. Logistic and Poisson regression models are used to check the effect of comorbidities on clinical outcomes.

Mitochondria Exert Age-Divergent Effects On Recovery From Spinal Cord Injury, Andrew N. Stewart, Katelyn E. Mcfarlane, Hemendra J. Vekaria, William M. Bailey, Stacey A. Slone, Lauren A. Tranthem, Bei Zhang, Samir P. Patel, Patrick G. Sullivan, John C. Gensel

Physiology Faculty Publications

The extent that age-dependent mitochondrial dysfunction drives neurodegeneration is not well understood. This study tested the hypothesis that mitochondria contribute to spinal cord injury (SCI)-induced neurodegeneration in an age-dependent manner by using 2,4-dinitrophenol (DNP) to uncouple electron transport, thereby increasing cellular respiration and reducing reactive oxygen species (ROS) production. We directly compared the effects of graded DNP doses in 4- and 14-month-old (MO) SCI-mice and found DNP to have increased efficacy in mitochondria isolated from 14-MO animals. In vivo, all DNP doses significantly exacerbated 4-MO SCI neurodegeneration coincident with worsened recovery. In contrast, low DNP doses (1.0-mg/kg/day) improved tissue …

Improving Evidence-Based Grouping Of Transitional Care Strategies In Hospital Implementation Using Statistical Tools And Expert Review, Jing Li, Gaixin Du, Jessica Miller Clouser, Arnold J. Stromberg, Glen Mays, Joann Sorra, Jane Brock, Terry Davis, Suzanne Mitchell, Huong Q. Nguyen, Mark V. Williams

Center for Health Services Research Faculty Publications

BACKGROUND: As health systems transition to value-based care, improving transitional care (TC) remains a priority. Hospitals implementing evidence-based TC models often adapt them to local contexts. However, limited research has evaluated which groups of TC strategies, or transitional care activities, commonly implemented by hospitals correspond with improved patient outcomes. In order to identify TC strategy groups for evaluation, we applied a data-driven approach informed by literature review and expert opinion.

METHODS: Based on a review of evidence-based TC models and the literature, focus groups with patients and family caregivers identifying what matters most to them during care transitions, and expert …

Time-Varying Insomnia Symptoms And Incidence Of Cognitive Impairment And Dementia Among Older Us Adults, Nicholas V. Resciniti, Valerie Yelverton, Bezawit Eyob Kase, Jiajia Zhang, Matthew C. Lohman

Faculty Publications

There is conflicting evidence regarding the association between insomnia and the onset of mild cognitive impairment (MCI) or dementia. This study aimed to evaluate if time-varying insomnia is associated with the development of MCI and dementia. Data from the Health and Retirement Study (n = 13,833) from 2002 to 2014 were used (59.4% female). The Brief Insomnia Questionnaire was used to identify insomnia symptoms which were compiled in an insomnia severity index, ranging from 0 to 4. In analysis, participants’ symptoms could vary from wave-to-wave. Dementia was defined using results from the Health and Retirement Study (HRS) global cognitive …

Analyzing And Creating Playing Card Cryptosystems, Isaac A. Reiter

Honors Student Research

Before computers, military tacticians and government agents had to rely on pencil-and-paper methods to encrypt information. For agents that want to use low-tech options in order to minimize their digital footprint, non-computerized ciphers are an essential component of their toolbox. Still, the presence of computers limits the pool of effective hand ciphers. If a cipher is not unpredictable enough, then a computer will easily be able to break it. There are 52! ≈ 2^225.58 ways to mix a deck of cards. If each deck order is a key, this means that there are 52! ≈ 2^225.58 different ways to encrypt …

Per- And Polyfluoroalkyl Substances And Kidney Function: Follow-Up Results From The Diabetes Prevention Program Trial, Pi-I D. Lin, Andres Cardenas, Russ Hauser, Diane R. Gold, Ken P. Kleinman, Marie-France Hivert, Antonia M. Calafat, Thomas F. Webster, Edward S. Horton, Emily Oken

Biostatistics and Epidemiology Faculty Publications Series

Per- and polyfluoroalkyl substances (PFAS) are ubiquitously detected in populations worldwide and may hinder kidney function. The objective of the study was to determine longitudinal associations of plasma PFAS concentrations with estimated glomerular filtration rate (eGFR) and evaluate whether a lifestyle intervention modify the associations. We studied 875 participants initially randomized to the lifestyle or placebo arms in the Diabetes Prevention Program (DPP, 1996–2002) trial and Outcomes Study (DPPOS, 2002–2014). We ran generalized linear mixed models accounting a priori covariates to evaluate the associations between baseline PFAS concentrations and repeated measures of eGFR, separately, for six PFAS (PFOS, PFOA, PFHxS, …

The Zoltar Forecast Archive, A Tool To Standardize And Store Interdisciplinary Prediction Research, Nicholas G. Reich, Matthew Cornell, Evan L. Ray, Katie House, Khoa Le

Biostatistics and Epidemiology Faculty Publications Series

Forecasting has emerged as an important component of informed, data-driven decision-making in a wide array of felds. We introduce a new data model for probabilistic predictions that encompasses a wide range of forecasting settings. This framework clearly defnes the constituent parts of a probabilistic forecast and proposes one approach for representing these data elements. The data model is implemented in Zoltar, a new software application that stores forecasts using the data model and provides standardized API access to the data. In one real-time case study, an instance of the Zoltar web application was used to store, provide access to, and …

Effect Of A Patient-Centered Hypertension Delivery Strategy On All-Cause Mortality: Secondary Analysis Of Search, A Community-Randomized Trial In Rural Kenya And Uganda, Matthew D. Hickey, James Ayieko, Asiphas Owaraganise, Nicholas Sim, Laura B. Balzer, Jane Kabami, Mucunguzi Atukunda, Frederick J. Opel, Erick Wafula, Et. Al.

Biostatistics and Epidemiology Faculty Publications Series

Background

Hypertension treatment reduces morbidity and mortality yet has not been broadly implemented in many low-resource settings, including sub-Saharan Africa (SSA). We hypothesized that a patient-centered integrated chronic disease model that included hypertension treatment and leveraged the HIV care system would reduce mortality among adults with uncontrolled hypertension in rural Kenya and Uganda.

Methods and findings

This is a secondary analysis of the SEARCH trial (NCT:01864603), in which 32 communities underwent baseline population-based multidisease testing, including hypertension screening, and were randomized to standard country-guided treatment or to a patient-centered integrated chronic care model including treatment for hypertension, diabetes, and HIV. …

Civilian-Military Malaria Outbreak Response In Thailand: An Example Of Multi-Stakeholder Engagement For Malaria Elimination, Michelle E. Roh, Kanyat Lausatianragit, Nithinart Chaitaveep, Krisada Jongsakul, Prayuth Sudathip, Chatree Raseebut, Sutchana Tabprasit, Prasert Nonkaew, Michele Spring, Montri Arsanok, Parat Boonyarangka, Sabaithip Sriwichai, Piayporn Sai-Ngam, Chaiyaporn Chaisatit, Peerapol Pokpong, Preecha Prempree, Sara Rossi, Mita Feldman, Mariusz Wojnarski, Adam Bennett, Roly Gosling, Danai Jearakul, Wanchai Lausatianragit, Philip L. Smith, Nicholas J. Martin, Andrew A. Lover, Mark M. Fukuda

Biostatistics and Epidemiology Faculty Publications Series

Background

In April 2017, the Thai Ministry of Public Health (MoPH) was alerted to a potential malaria outbreak among civilians and military personnel in Sisaket Province, a highly forested area bordering Cambodia. The objective of this study was to present findings from the joint civilian-military outbreak response.

Methods

A mixed-methods approach was used to assess risk factors among cases reported during the 2017 Sisaket malaria outbreak. Routine malaria surveillance data from January 2013 to March 2018 obtained from public and military medical reporting systems and key informant interviews (KIIs) (n = 72) were used to develop hypotheses about potential factors …

Fourth Down Decision Making: Challenging The Conservative Nature Of Nfl Coaches, Will Palmquist, Ryan Elmore, Benjamin Williams

DU Undergraduate Research Journal Archive

This thesis analyzes the hypothesis that coaches in the National Football League are often too conservative in their decision making on fourth downs. I used R Studio and NFL play-by-play data to simulate actual football plays and drives according to different fourth down strategies. By measuring expected points per drive over thousands of simulated drives, we are able to evaluate the effectiveness of different fourth down strategies. This research points to a number of conclusions regarding the nature of NFL coaches on fourth downs as well as the complexity of modeling and simulating decision making in a complex sport such …

Prevalence Of Glucose-6-Phosphate Dehydrogenase Deficiency (G6pdd) Carestart Qualitative Rapid Diagnostic Test Performance, And Genetic Variants In Two Malaria-Endemic Areas In Sudan, Musab M. Ali Albsheer, Andrew A. Lover, Sara B. Eltom, Leena Omereltinai, Nouh Mohamed, Mohamed S. Muneer, Abdelrahim O. Mohamad, Muzamil Mahdi Abdel Hamid

Biostatistics and Epidemiology Faculty Publications Series

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is the most common enzymopathy globally, and deficient individuals may experience severe hemolysis following treatment with 8-aminoquinolines. With increasing evidence of Plasmodium vivax infections throughout sub-Saharan Africa, there is a pressing need for population-level data at on the prevalence of G6PDd. Such evidence-based data will guide the expansion of primaquine and potentially tafenoquine for radical cure of P. vivax infections. This study aimed to quantify G6PDd prevalence in two geographically distinct areas in Sudan, and evaluating the performance of a qualitative CareStart rapid diagnostic test as a point-of-care test. Blood samples were analyzed from 491 …

In Utero Exposure To Persistent Organic Pollutants And Childhood Lipid Levels, Maegan E. Boutot, Brian W. Whitcomb, Nadia Abdelouahab, Andrea A. Baccarelli, Amélie Boivin, Artuela Caku, Virginie Gillet, Guillaume Martinez, Jean-Charles Pasquier, Jiping Zhu, Larissa Takser, Lindsay St-Cyr, Alexander Suvorov

Biostatistics and Epidemiology Faculty Publications Series

Animal studies have shown that developmental exposures to polybrominated diphenyl ethers (PBDE) permanently affect blood/liver balance of lipids. No human study has evaluated associations between in utero exposures to persistent organic pollutants (POPs) and later life lipid metabolism. In this pilot, maternal plasma levels of PBDEs (BDE-47, BDE-99, BDE-100, and BDE-153) and polychlorinated biphenyls (PCB-138, PCB-153, and PCB-180) were determined at delivery in participants of GESTation and Environment (GESTE) cohort. Total cholesterol (TCh), triglycerides (TG), low- and high-density lipoproteins (LDL-C and HDL-C), total lipids (TL), and PBDEs were determined in serum of 147 children at ages 6–7. General linear regression …

Evaluating Epidemic Forecasts In An Interval Format, Johannes Bracher, Evan L. Ray, Tilmann Gneiting, Nicholas G. Reich

Biostatistics and Epidemiology Faculty Publications Series

For practical reasons, many forecasts of case, hospitalization, and death counts in the context of the current Coronavirus Disease 2019 (COVID-19) pandemic are issued in the form of central predictive intervals at various levels. This is also the case for the forecasts collected in the COVID-19 Forecast Hub (https://covid19forecasthub.org/). Forecast evaluation metrics like the logarithmic score, which has been applied in several infectious disease forecasting challenges, are then not available as they require full predictive distributions. This article provides an overview of how established methods for the evaluation of quantile and interval forecasts can be applied to epidemic forecasts in …