Physical Sciences and Mathematics Commons^™

Forecasting Covid-19 With Temporal Hierarchies And Ensemble Methods, Li Shandross

Masters Theses

Infectious disease forecasting efforts underwent rapid growth during the COVID-19 pandemic, providing guidance for pandemic response and about potential future trends. Yet despite their importance, short-term forecasting models often struggled to produce accurate real-time predictions of this complex and rapidly changing system. This gap in accuracy persisted into the pandemic and warrants the exploration and testing of new methods to glean fresh insights.

In this work, we examined the application of the temporal hierarchical forecasting (THieF) methodology to probabilistic forecasts of COVID-19 incident hospital admissions in the United States. THieF is an innovative forecasting technique that aggregates time-series data into …

Differential Toxicity Of Pm2.5 Components And Modified Health Effects Modeling: A Case Study In Nepal, Jeremy Brownholtz

Masters Theses

During the latter part of the 20^th century, a transition away from coal as a major energy source in developed countries was accompanied by a notable decrease in air pollution-related deaths in those countries. Currently the same phenomenon is being observed in developing nations like China and India. However, many areas that do still rely on coal for their energy production or industrial needs also reflect a gap in research on the effects of those specific processes on local populations. Located in Nepal at the foot of the Himalayan Plateau, Kathmandu represents one such location. The local economy of …

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 …

Decision-Analytic Models Using Reinforcement Learning To Inform Dynamic Sequential Decisions In Public Policy, Seyedeh Nazanin Khatami

Doctoral Dissertations

We developed decision-analytic models specifically suited for long-term sequential decision-making in the context of large-scale dynamic stochastic systems, focusing on public policy investment decisions. We found that while machine learning and artificial intelligence algorithms provide the most suitable frameworks for such analyses, multiple challenges arise in its successful adaptation. We address three specific challenges in two public sectors, public health and climate policy, through the following three essays. In Essay I, we developed a reinforcement learning (RL) model to identify optimal sequence of testing and retention-in-care interventions to inform the national strategic plan “Ending the HIV Epidemic in the US”. …

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. …

The Role Of Vegetative Cover In Enhancing Resilience To Climate Change And Improving Public Health, Anastasia D. Ivanova

Masters Theses

Changing temperature and precipitation patterns are causing degraded soil, water, and air quality which is negatively affecting the safety and health of people, and the productivity of urban and rural communities. However, research shows that implementing urban forests and cover crops into urban and rural landscapes, respectively, can mitigate these effects by providing ecosystem services. As extreme precipitation and heat events continue to intensify, there is a need for comprehensively assessing these ecosystem services under changing climates and for this information to be easily accessible by communities for rapid land-use decision making. Therefore, I investigated the role of urban forests …

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 …

A Comparative Sustainability Study For Treatment Of Domestic Wastewater: Conventional Concrete And Steel Technology Vs. Vegetated Sand Beds (Vsb’S) And Their Relative Differences In Co2 Production, Alicia M. Milch

Masters Theses

Conventional wastewater treatment in the U.S. is an energy dependent and carbon dioxide emitting process. Typical mechanical systems consume copious amounts of energy, which is most commonly produced from fossil fuel combustion that results in the production of CO₂. The associated organic load is also metabolized by microorganisms into CO₂ and H₂O. As the desire to reduce CO₂ output becomes more prominent, it is logical to assess the costs of conventional treatment methods and to compare them to alternative, more sustainable technology. Vegetated Sand Bed (VSB) and Reed Bed (RB) systems are green technologies …

Evaluating Predictors Of An Individual’S Dietary Intake Latent Value Under Different Mixed Models, Shuli Yu

Doctoral Dissertations

The accurate estimation of an individual’s usual dietary intake is important since the estimates are essential to uncover the diet-disease relationships. This study explores a more accurate method to estimate an individual’s latent value of usual dietary intake when it is repeatedly measured using a 24-hour dietary recall (24HR) and seven day dietary recall (7DDR), accounting for random measurement error and bias. The performance of the (empirical) predictor of subject’s latent value obtained under the finite population mixed model (FPMM) framework is compared with those obtained under the usual mixed model and the measurement error model through a simulation study. …

In Silico Surveillance: Evaluating Outbreak Detection With Simulation Models, Bryan Lewis, Stephen Eubank, Allyson M. Abrams, Ken Kleinman

Public Health Department Faculty Publication Series

Background

Detecting outbreaks is a crucial task for public health officials, yet gaps remain in the systematic evaluation of outbreak detection protocols. The authors’ objectives were to design, implement, and test a flexible methodology for generating detailed synthetic surveillance data that provides realistic geographical and temporal clustering of cases and use to evaluate outbreak detection protocols.

Methods

A detailed representation of the Boston area was constructed, based on data about individuals, locations, and activity patterns. Influenza-like illness (ILI) transmission was simulated, producing 100 years ofin silico ILI data. Six different surveillance systems were designed and developed using gathered cases …

Correlations Among Adiposity Measures In School-Aged Children, Caroline E. Boeke, Emily Oken, Ken P. Kleinman, Sheryl L. Rifas-Shiman, Elsie M. Taveras, Matthew W. Gillman

Public Health Department Faculty Publication Series

BACKGROUND:

Given that it is not feasible to use dual x-ray absorptiometry (DXA) or other reference methods to measure adiposity in all pediatric clinical and research settings, it is important to identify reasonable alternatives. Therefore, we sought to determine the extent to which other adiposity measures were correlated with DXA fat mass in school-aged children.

METHODS:

In 1110 children aged 6.5-10.9 years in the pre-birth cohort Project Viva, we calculated Spearman correlation coefficients between DXA (n=875) and other adiposity measures including body mass index (BMI), skinfold thickness, circumferences, and bioimpedance. We also computed correlations between lean body mass measures.

RESULTS: …

Childhood Body Mass Index Trajectories: Modeling, Characterizing, Pairwise Correlations And Socio-Demographic Predictors Of Trajectory Characteristics, Xiaozhong Wen, Ken Kleinman, Matthew W. Gillman, Sherly L. Rifas-Shiman, Elsie M. Taveras

Public Health Department Faculty Publication Series

BACKGROUND:

Modeling childhood body mass index (BMI) trajectories, versus estimating change in BMI between specific ages, may improve prediction of later body-size-related outcomes. Prior studies of BMI trajectories are limited by restricted age periods and insufficient use of trajectory information.

METHODS:

Among 3,289 children seen at 81,550 pediatric well-child visits from infancy to 18 years between 1980 and 2008, we fit individual BMI trajectories using mixed effect models with fractional polynomial functions. From each child's fitted trajectory, we estimated age and BMI at infancy peak and adiposity rebound, and velocity and area under curve between 1 week, infancy peak, adiposity …

Estimation Of Newborn Risk For Child Or Adolescent Obesity:Lessons From Longitudinal Birth Cohorts, Anita Morandi, David Meyre, Stephane Lobbens, Ken Kleinman, Marika Kaakinen, Sheryl L. Rifas-Shiman, Vincent Vatin, Stefan Gaget, Anneli Pouta, Anna-Liisa Hartikainen, Jaana Laitinen, Matthew W. Gillman, Marjo-Riitta Jarvelin, Philippe Froguel

Public Health Department Faculty Publication Series

OBJECTIVES:

Prevention of obesity should start as early as possible after birth. We aimed to build clinically useful equations estimating the risk of later obesity in newborns, as a first step towards focused early prevention against the global obesity epidemic.

METHODS:

We analyzed the lifetime Northern Finland Birth Cohort 1986 (NFBC1986) (N = 4,032) to draw predictive equations for childhood and adolescent obesity from traditional risk factors (parental BMI, birth weight, maternal gestational weight gain, behaviour and social indicators), and a genetic score built from 39 BMI/obesity-associated polymorphisms. We performed validation analyses in a retrospective cohort of 1,503 Italian children …

Determinants Of Health Care Use Among Rural, Low-Income Mothers And Children: A Simultaneous Systems Approach To Negative Binomial Regression Modeling, Swetha Valluri

Masters Theses 1911 - February 2014

The determinants of health care use among rural, low-income mothers and their children were assessed using a multi-state, longitudinal data set, Rural Families Speak. The results indicate that rural mothers’ decisions regarding health care utilization for themselves and for their child can be best modeled using a simultaneous systems approach to negative binomial regression. Mothers’ visits to a health care provider increased with higher self-assessed depression scores, increased number of child’s doctor visits, greater numbers of total children in the household, greater numbers of chronic conditions, need for prenatal or post-partum care, development of a new medical condition, and …

Approaches To Estimation Of Haplotype Frequencies And Haplotype-Trait Associations, Xiaohong Li

Doctoral Dissertations 1896 - February 2014

Characterizing the genetic contributors to complex disease traits will inevitably require consideration of haplotypic phase, the specific alignment of alleles on a single homologous chromosome. In population based studies, however, phase is generally unobservable as standard genotyping techniques provide investigators only with data on unphased genotypes. Several statistical methods have been described for estimating haplotype frequencies and their association with a trait in the context of phase ambiguity. These methods are limited, however, to diploid populations in which individuals have exactly two homologous chromosomes each and are thus not suitable for more general infectious disease settings. Specifically, in the context …

A Satscan Macro Accessory For Cartography (Smac) Package Implemented With Sas Software, Allyson M. Abrams, Ken P. Kleinman

Public Health Department Faculty Publication Series

BACKGROUND:

SaTScan is a software program written to implement the scan statistic; it can be used to find clusters in space and/or time. It must often be run multiple times per day when doing disease surveillance. Running SaTScan frequently via its graphical user interface can be cumbersome, and the output can be difficult to visualize.

RESULTS:

The SaTScan Macro Accessory for Cartography (SMAC) package consists of four SAS macros and was designed as an easier way to run SaTScan multiple times and add graphical output. The package contains individual macros which allow the user to make the necessary input files …

Evaluating Spatial Surveillance: Detection Of Known Outbreaks In Real Data, Ken Kleinman, Allyson Abrams, W. Katherine Yih, Richard Platt, Martin Kulldorff

Public Health Department Faculty Publication Series

Since the anthrax attacks of October 2001 and the SARS outbreaks of recent years, there has been an increasing interest in developing surveillance systems to aid in the early detection of such illness. Systems have been established which do this is by monitoring primary health-care visits, pharmacy sales, absenteeism records, and other non-traditional sources of data. While many resources have been invested in establishing such systems, relatively little effort has as yet been expended in evaluating their performance.

One way to evaluate a given surveillance system is to compare the signals it generates with known outbreaks identified in other systems. …

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 …

Correlates Of Parental Antibiotic Knowledge, Demand, And Reported Use, Marianne Kuzujanakis, Ken Kleinman, Sheryl Rifas-Shiman, Jonathan A. Finkelstein

Public Health Department Faculty Publication Series

Clinicians cite parental misconceptions and requests for antibiotics as reasons for inappropriate prescribing. To identify misconceptions regarding antibiotics and predictors of parental demand for antibiotics and to determine if parental knowledge and attitudes are associated with use. Survey of parents in 16 Massachusetts communities. Domains included antibiotic-related knowledge, attitudes about antibiotics, antibiotic use during a 12-month period, demographics, and access to health information. Bivariate and multivariate analyses evaluated predictors of knowledge and proclivity to demand antibiotics. A multivariate model evaluated the associations of knowledge, demand, and demographic factors with parent-reported antibiotic use. A total of 1106 surveys were returned (response …

Middlefield Open Space And Recreation Project, Center For Economic Development

Center for Economic Development Technical Reports

Over one thousand acres of farmland, open space, and wetlands are converted to residential or commercial development each week in New England. In Massachusetts, nearly two acres of open space land is lost to development every hour. Current development trends suggest that this building pattern, referred to as sprawl, is likely to continue into the near future. Because the negative consequences of sprawl development are highly visible, residents of Massachusetts are becoming increasingly concerned about its impact on their communities. Residents see the unique character of their communities being transformed by uncontrolled residential and commercial development. Green fields and open …

City Of Gardner, Massachusetts Inventory Of Existing And Removed Tanks, Center For Economic Development

Center for Economic Development Technical Reports

The purpose of this project is to provide the City of Gardner with a list of contaminated sites in the Rear Main Street Area. During the past month, I have been researching potential brownfield locations within this corridor, and inputting them into a working database. Overall, the problem identified is that the city has little knowledge of how much land is contaminated within its city. Therefore, the goal of my project was to identify the parcels in the Rear Main Street Area that have been contaminated with hazardous materials.