Physical Sciences and Mathematics Commons^™

Three Dimensional Spatio-Temporal Cluster Analysis Of Sars-Cov-2 Infections, Keith W. Allison

Masters Theses

The COVID-19 pandemic has heightened the need for fine-scale analysis of the clustering of cases of infectious disease in order to better understand and prevent the localized spread of infection. The students living on the University of Massachusetts, Amherst campus provided a unique opportunity to do so, due to frequent mandatory testing during the 2020-2021 academic year, and dense living conditions. The South-West dormitory area is of particular interest due to its extremely high population density, housing around half of students living on campus during normal conditions. Using data gathered by the Public Health Promotion Center (PHPC), we analyzed the …

High-Dimensional Feature Selection And Multi-Level Causal Mediation Analysis With Applications To Human Aging And Cluster-Based Intervention Studies, Hachem Saddiki

Doctoral Dissertations

Many questions in public health and medicine are fundamentally causal in that our objective is to learn the effect of some exposure, randomized or not, on an outcome of interest. As a result, causal inference frameworks and methodologies have gained interest as a promising tool to reliably answer scientific questions. However, the tasks of identifying and efficiently estimating causal effects from observed data still pose significant challenges under complex data generating scenarios. We focus on (1) high-dimensional settings where the number of variables is orders of magnitude higher than the number of observations; and (2) multi-level settings, where study participants …

Evaluating Public Masking Mandates On Covid-19 Growth Rates In U.S. States, Angus K. Wong

Masters Theses

U.S. state governments have implemented numerous policies to help mitigate the spread of COVID-19. While there is strong biological evidence supporting the wearing of face masks or coverings in public spaces, the impact of public masking policies remains unclear. We aimed to evaluate how early versus delayed implementation of state-level public masking orders impacted subsequent COVID-19 growth rates. We defined “early” implementation as having a state-level mandate in place before September 1, 2020, the approximate start of the school-year. We defined COVID-19 growth rates as the relative increase in confirmed cases 7, 14, 21, 30, 45, 60-days after September 1. …

A Comparison Of Techniques For Handling Missing Data In Longitudinal Studies, Alexander R. Bogdan

Masters Theses

Missing data are a common problem in virtually all epidemiological research, especially when conducting longitudinal studies. In these settings, clinicians may collect biological samples to analyze changes in biomarkers, which often do not conform to parametric distributions and may be censored due to limits of detection. Using complete data from the BioCycle Study (2005-2007), which followed 259 premenopausal women over two menstrual cycles, we compared four techniques for handling missing biomarker data with non-Normal distributions. We imposed increasing degrees of missing data on two non-Normally distributed biomarkers under conditions of missing completely at random, missing at random, and missing not …

Sleep Patterns, Urinary Levels Of Melatonin And Subsequent Weight Change In The Women’S Health Initiative Observational Study, Nicole M. Barron

Masters Theses

Results from prospective studies examining associations between sleep duration and weight gain have been mixed. Melatonin has been hypothesized to mediate the association between sleep duration and weight/body composition. In cross-sectional studies, aMT6s has been shown to be inversely associated with weight/body fat percentage. We examined associations between baseline sleep duration, insomnia status, aMT6s levels with weight/body fat percentage through 6 years, utilizing a subset 690 women who participated in a breast cancer case-control study nested within the WHI-OS. Multi-variable and mixed-effects regression was used to calculate beta-coefficients and 95% confidence intervals. Cross-sectional analyses showed urinary aMT6s levels were inversely …

Variation In Hepatitis B Immunization Coverage Rates Associated With Provider Practices After The Temporary Suspension Of The Birth Dose, Nancy D. Lin, Ken Kleinman, K Arnold Chan, Xian-Jie Yu, Eric K. France, Feifei Wei, John P. Mullooly, Steven Black, David Shay, Margarette Kolczak, Tracey Lieu, Vaccine Safety Datalink Team

Public Health Department Faculty Publication Series

Background

In 1999, the American Academy of Pediatrics and U.S. Public Health Service recommended suspending the birth dose of hepatitis B vaccine due to concerns about potential mercury exposure. A previous report found that overall national hepatitis B vaccination coverage rates decreased in association with the suspension. It is unknown whether this underimmunization occurred uniformly or was associated with how providers changed their practices for the timing of hepatitis B vaccine doses. We evaluate the impact of the birth dose suspension on underimmunization for the hepatitis B vaccine series among 24-month-olds in five large provider groups and describe provider practices …

Impact Of The Introduction Of Pneumococcal Conjugate Vaccine On Immunization Coverage Among Infants, Nancy D. Lin, Ken Kleinman, K Arnold Chan, Xian-Jie Yu, Eric K. France, Stanley Xu, Feifei Wei, John Mullooly, Jeanne Santoli, Tracey A. Lieu, Vaccine Safety Datalink Group

Public Health Department Faculty Publication Series

Background

The introduction of pneumococcal conjugate vaccine (PCV) to the U.S. recommended childhood immunization schedule in the year 2000 added three injections to the number of vaccinations a child is expected to receive during the first year of life. Surveys have suggested that the addition of PCV has led some immunization providers to move other routine childhood vaccinations to later ages, which could increase the possibility of missing these vaccines. The purpose of this study was to evaluate whether introduction of PCV affected immunization coverage for recommended childhood vaccinations among 13-month olds in four large provider groups.

Methods

In this …

Group Versus Individual Academic Detailing To Improve The Use Of Antihypertensive Medications In Primary Care: A Cluster-Randomized Controlled Trial, Steven R. Simon, Sumit R. Majumdar, Lisa A. Prosser, Susanne Salem-Schatz, Cheryl Warner, Ken Kleinman, Irina Miroshnik, Stephen B. Soumerai

Public Health Department Faculty Publication Series

Purpose

To compare group versus individual academic detailing to increase diuretic or β-blocker use in hypertension.

Methods

We conducted a cluster-randomized controlled trial in a large health maintenance organization. Subjects (N=9820) were patients with newly treated hypertension in the year preceding the intervention (N=3692), the 9 months following the intervention (N=3556), and the second year following intervention (N=2572). We randomly allocated 3 practice sites to group detailing (N=227 prescribers), 3 to individual detailing (N=235 prescribers), and 3 to usual care (N=319 prescribers). Individual detailing entailed a physician-educator meeting individually with clinicians to address barriers to prescribing guideline-recommended medications. The group …

Maternal Age And Other Predictors Of Newborn Blood Pressure, Matthew Gillman, Janet W. Rich-Edwards, Sheryl L. Rifas-Shiman, Ellice S. Lieberman, Ken Kleinman, Steven Lipshultz

Public Health Department Faculty Publication Series

Objective

To investigate perinatal predictors of newborn blood pressure.

Study design

Among 1059 mothers and their newborn infants participating in Project Viva, a US cohort study of pregnant women and their offspring, we obtained five systolic blood pressure readings on a single occasion in the first few days of life. Using multivariate linear regression models, we examined the extent to which maternal age and other pre- and perinatal factors predicted newborn blood pressure level.

Results

Mean (SD) maternal age was 32.0 (5.2) years, and mean (SD) newborn systolic blood pressure was 72.6 (9.0) mm Hg. A multivariate model showed that …

Child Care Center Policies And Practices For Management Of Ill Children, Jennifer F. Friedman, Grace M. Lee, Ken P. Kleinman, Jonathan A. Finkelstein

Public Health Department Faculty Publication Series

OBJECTIVES:

The objectives of this study were to 1) describe child care staff knowledge and beliefs regarding upper respiratory tract infections and antibiotic indications and 2) evaluate child care staff reported reasons for a) exclusion from child care, b) referral to a health care provider, and c) recommending antibiotics for an ill child.

METHODS:

A longitudinal study based in randomly selected child care centers in Massachusetts. Staff completed a survey to assess knowledge regarding common infections. For six weeks, staff completed a record of absences each day, describing the reason for an absence, and advice given to the parents regarding …