Modeling Tick-Borne Disease in Iowa Nationwide, tick-borne illness has been rising, and Iowa is no exception. In particular, Lyme disease has captured national attention due to the potentially severe and long lasting side effects which can be produced. The lifecycles of the infectious organisms are complex, relying on multiple tick developmental stages, as well as the presence of an infected reservoir (mice) to preserve the pathogen between tick generations. In this project, we will examine tick-borne illness over space and time within the state of Iowa, with a particular focus on how weather events and climactic factors impact the spread of human disease. We will produce interactive maps, and will explore the use of spatiotemporal statistical models for forecasting.
Evaluating the impact of timing of antiretroviral therapy initiation on outcomes in human immunodeficiency virus-infected adults According to the World Health Organization, over 1.1 million people with AIDS died in 2016. As of 2017, approximately 36.9 million people are living with human immunodeficiency virus (HIV) that causes AIDS. HIV destroys immune system cells, leaving infected individuals susceptible to other infections. At the beginning of the AIDS epidemic, most HIV-infected people died within 10 years of infection. In 1996, highly active antiretroviral therapy (ART) became available, but ART was extremely expensive and thereby a diagnosis of HIV infection remained a death sentence for people living in developing countries. This situation was declared a global health emergency in 2003. Governments, international agencies and funding bodies began to implement plans to increase ART coverage in low- and middle-income countries and people in the countries initiated ART on the basis of guidelines. However, international guidelines differ on when to start ART because the optimal timing for initiation of ART remains uncertain. In this project, we will evaluate the impact of the timing of ART initiation on outcomes in HIV-infected adults in Haiti.
Heat Waves and Cold Snaps: Trends in Temperature Extremes and Associated Health Effects Heat waves kill more Americans than other natural disasters such as floods, lightning, tornadoes, and hurricanes.* Are they becoming more frequent or more severe? What about dangerously cold weather? This project will explore trends in the occurrence of extremely hot and extremely cold temperatures in the continental United States and in associated morbidity and mortality over the last century. *Altman, Peter. “Killer Summer Heat: Projected Death Toll from Rising Temperatures in America Due to Climate Change.” Natural Resources Defense Council, 2012.
An Analysis of the Efficacy of State Policies Designed to Address Bullying and Other Forms of Youth Violence Youth violence in the United States is common and is associated with numerous adverse academic, health, and psychosocial outcomes. Programs aimed at preventing youth violence have shown only modest success. Consequently, researchers have begun exploring additional primary prevention strategies that can augment existing programs, including anti-bullying policies. Though all 50 states have enacted some type of anti-bullying legislation, there is a striking dearth of research on the efficacy of such laws in preventing bullying and other forms of youth violence (i.e dating violence, physical fighting, suicidality, etc). In order to begin to address this deficiency, we will perform analyses based on individual-level survey data supplied by the Youth Risk Behavioral Surveillance System (YRBSS) in conjunction with a comprehensive legal dataset that codifies anti-violence laws (and amendments) from their inception in 1999 through 2017.
Inadequate sleep and unhealthy metabolism: Insights from the National Health and Nutrition Examination Survey Many recent studies have shown that sleep is an important determinant of human health and proper metabolism. Unfortunately, 35% of Americans are not getting the recommended amount of sleep at night. To learn more about this issue, the National Health and Nutrition Examination Survey (NHANES) has recently started collecting data on sleep duration, timing, and quality. Although the relationships between sleep and some biological outcomes, such as BMI, are well-studied, sleep’s relationship with metabolism is less well understood. This project’s goal is to investigate and quantify these relationships as well as to understand other factors that may modify those relationships.
Predicting Recurrence in T1 High Grade Bladder Cancer Patients with high grade T1 bladder cancer are at high risk for disease recurrence, which is a major determinant of long-term outcome. The 2016 American Urological Association guidelines for treatment of patients with recurrent disease after an intravesical treatment course of bacillus Calmette-Guerin BCG recommend removal of the urinary bladder (cystectomy). However, with the advent of newer treatment options, the dilemma for urologists is how to select patients for bladder-conserving therapies versus more aggressive radical cystectomy. For this project, recurrent event statistical methods will be employed to identify characteristics predictive of recurrence, develop multivariable models, and assess the predictive performance of the models.
Reducing High-frequency Driving Data from Instrumented Vehicles and Simulators Despite new technologies, safety equipment, and progressive legislations, motor vehicle crashes remain one of the most common causes of accidental death in the U.S. We have had many years of experience investigating how neurological disease, cognitive factors, and demographics affect various driving outcomes measured in simulators, in our own instrumented vehicles, and in individual vehicles fit with “black box” sensors. One enduring challenge is finding appropriate methods to reduce high volumes of electronic data, measured at 10-30 Hz over long periods of time, into meaningful metrics. Although we have proposed specific statistical models that have showed much promise in this area, more work is needed to explore the statistical and empirical properties of such models. In this project, we will fit these models to real and simulated data in order to make recommendations of how to defined meaningful driving metrics in future studies.
Spatio-Temporal Risk for Infantile Hypertrophic Pyloric Stenosis among a 20-year Cohort of Iowa Births The Iowa Registry for Congenital and Inherited Disorders (IRCID) conducts statewide surveillance for major structural birth defects diagnosed among pregnancies of Iowa residents. Infantile hypertrophic pyloric stenosis (IHPS) results from the muscular hypertrophy of the pyloric sphincter, which causes obstruction of the gastric outlet and projectile vomiting in the infant. Unlike many other structural birth defects that present at birth, IHPS typically presents 2-12 weeks after birth, uniquely extending the risk period for this defect from early fetal life to early postnatal life. Previous studies suggest that the etiology of IHPS is multifactorial, with several genetic and environmental (broadly defined) antecedents. The most consistently reported observed antecedents are male sex and non-Hispanic white race/ethnicity; remaining antecedents observed largely are equivocal. The predisposition for IHPS varies across decades and geographic regions, due perhaps to differences in racial/ethnic distributions in these regions, but also perhaps to other unidentified risk factors related to environmental exposures, socioeconomic factors, neighborhood effects, etc. Lacking are detailed studies of spatio-temporal risk for this defect in a well-described cohort. Using a 20-year cohort of IHPS cases ascertained by the IRCID and statewide birth data for this same time period, this project will investigate spatio-temporal risks for IHPS using disease mapping spatial statistics and longitudinal data analysis methods. This analysis will provide important insights into geographic areas of increased risk, how risk has changed over time, and factors that may be related to changes in risk.