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Articles 5941 - 5970 of 12830

Full-Text Articles in Statistics and Probability

Visualizing Lab And Phenotype Associations Using Phewas And Electronic Health Records, Brenda Emerson, Miriam Goldman, Sahiti Kolli Jul 2017

Visualizing Lab And Phenotype Associations Using Phewas And Electronic Health Records, Brenda Emerson, Miriam Goldman, Sahiti Kolli

Honors Projects

As the digitization of patient health records is becoming more common, we are given a great opportunity to analyze these records and hopefully make discoveries about diseases or medicines. Being given large datasets of Electronic Health Records, I and two other students decided to look for novel phenotype associations with mean lab values, look to see whether the presence of a lab had associations with a phenotype, and create an interactive application to visual the associations between labs and phenotypes.


Burden Of Atopic Dermatitis In The United States: Analysis Of Healthcare Claims Data In The Commercial, Medicare, And Medi-Cal Databases, Sulena Shrestha, Raymond Miao, Li Wang, Jingdong Chao, Huseyin Yuce, Wenhui Wei Jul 2017

Burden Of Atopic Dermatitis In The United States: Analysis Of Healthcare Claims Data In The Commercial, Medicare, And Medi-Cal Databases, Sulena Shrestha, Raymond Miao, Li Wang, Jingdong Chao, Huseyin Yuce, Wenhui Wei

Publications and Research

Comparative data on the burden of atopic dermatitis (AD) in adults relative to the general population are limited. We performed a large-scale evaluation of the burden of disease among US adults with AD relative to matched non-AD controls, encompassing comorbidities, healthcare resource utilization (HCRU), and costs, using healthcare claims data. The impact of AD disease severity on these outcomes was also evaluated.


Comparison Of Two Methods In Estimating Standard Error Of Simulated Moments Estimators For Generalized Linear Mixed Models, Danielle K. Duran Jul 2017

Comparison Of Two Methods In Estimating Standard Error Of Simulated Moments Estimators For Generalized Linear Mixed Models, Danielle K. Duran

Mathematics & Statistics ETDs

We consider standard error of the method of simulated moment (MSM) estimator for generalized linear mixed models (GLMM). Parametric bootstrap (PB) has been used to estimate the covariance matrix, in which we use the estimates to generate the simulated moments. To avoid the bias introduced by estimating the parameters and to deal with the correlated observations, (Lu, 2012) proposed a multi-stage block nonparametric bootstrap to estimate the standard errors. In this research, we compare PB and nonparametric bootstrap methods (NPB) in estimating the standard errors of MSM estimators for GLMM. Simulation results show that when the group size is large, …


A Perspective On The Challenges And Issues In Developing Biomarkers For Human Allergic Risk Assessments, Ying Mu, Dianne E. Godar, Stephen Merrill Jul 2017

A Perspective On The Challenges And Issues In Developing Biomarkers For Human Allergic Risk Assessments, Ying Mu, Dianne E. Godar, Stephen Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.


Bayesian Artificial Neural Networks In Health And Cybersecurity, Hansapani Sarasepa Rodrigo Jul 2017

Bayesian Artificial Neural Networks In Health And Cybersecurity, Hansapani Sarasepa Rodrigo

USF Tampa Graduate Theses and Dissertations

Being in the era of Big data, the applicability and importance of data-driven models like artificial neural network (ANN) in the modern statistics have increased substantially. In this dissertation, our main goal is to contribute to the development and the expansion of these ANN models by incorporating Bayesian learning techniques. We have demonstrated the applicability of these Bayesian ANN models in interdisciplinary research including health and cybersecurity.

Breast cancer is one of the leading causes of deaths among females. Early and accurate diagnosis is a critical component which decides the survival of the patients. Including the well known ``Gail Model", …


Mining Diverse Consumer Preferences For Bundling And Recommendation, Ha Loc Do Jul 2017

Mining Diverse Consumer Preferences For Bundling And Recommendation, Ha Loc Do

Dissertations and Theses Collection

That consumers share similar tastes on some products does not guarantee their agreement on other products. Therefore, both similarity and dierence should be taken into account for a more rounded view on consumer preferences. This manuscript focuses on mining this diversity of consumer preferences from two perspectives, namely 1) between consumers and 2) between products. Diversity of preferences between consumers is studied in the context of recommendation systems. In some preference models, measuring similarities in preferences between two consumers plays the key role. These approaches assume two consumers would share certain degree of similarity on any products, ignoring the fact …


Letter To The Editor, Jarrod Bailey Jul 2017

Letter To The Editor, Jarrod Bailey

Validation of Animal Experimentation Collection

It seems clear that heeding the opinions and recommendations of experienced neuroscientists such as Professor Beuter, the well-argued probable opinion of the time-travelling Parkinson, and Grimm and Eggel’s demands for high animal welfare and honest and realistic harm–benefit analyses, will be of paramount importance for the advancement and evolution of experiments involving NHPs, particularly in neuroscience. This will benefit animals and humans alike.


Motion-Capture-Based Hand Gesture Recognition For Computing And Control, Andrew Gardner Jul 2017

Motion-Capture-Based Hand Gesture Recognition For Computing And Control, Andrew Gardner

Doctoral Dissertations

This dissertation focuses on the study and development of algorithms that enable the analysis and recognition of hand gestures in a motion capture environment. Central to this work is the study of unlabeled point sets in a more abstract sense. Evaluations of proposed methods focus on examining their generalization to users not encountered during system training.

In an initial exploratory study, we compare various classification algorithms based upon multiple interpretations and feature transformations of point sets, including those based upon aggregate features (e.g. mean) and a pseudo-rasterization of the capture space. We find aggregate feature classifiers to be balanced across …


Lecture Notes For Openstax Introductory Statistics, Daphne Skipper, Neal Smith, Robert Scott, Marvalisa Payne, Christopher Terry Jul 2017

Lecture Notes For Openstax Introductory Statistics, Daphne Skipper, Neal Smith, Robert Scott, Marvalisa Payne, Christopher Terry

Mathematics Ancillary Materials

Authors' Description:

"Rising textbook costs are a potential barrier to student progression and retention. Therefore, a group of faculty in the department of Mathematics at Augusta University has decided to adopt an open textbook for use in an Elementary Statistics course.

We have developed a set of materials to accompany the OpenStax Introductory Statistics textbook by Illowsky and Dean including lecture/study notes and projects.

These materials are meant as a supplement for teachers and learners who are using the OpenStax Introductory Statistics textbook by Illowsky and Dean. These materials also incorporate the use of other technologies (R and Excel) in …


Failure Of Care Acquisition: Identifying Risk Factors In American Health Disparities, Nicholas Downing, Mamunur Rashid Jul 2017

Failure Of Care Acquisition: Identifying Risk Factors In American Health Disparities, Nicholas Downing, Mamunur Rashid

Student Research

We examined the effects of various demographic and socioeconomic risk factors that influence an adult's decision not to obtain medical care in the United States utilizing data from the 2015 National Health Interview Survey (NHIS). Bivariate analysis and multivariate logistic regression revealed that family income, insurance status and whether one worries about paying medical bills make individuals nearly 80% less likely to obtain care than their counterparts. This study provides evidence that certain risk factors, especially those directly related to one's socioeconomic status, may put individuals at greater risk for failure to obtain care. Interventions in policy may be needed …


Elementary Statistics (Augusta), Neal Smith, Daphne Skipper, Marvalisa Payne, Robert Scott, Christopher Terry Jul 2017

Elementary Statistics (Augusta), Neal Smith, Daphne Skipper, Marvalisa Payne, Robert Scott, Christopher Terry

Mathematics Grants Collections

This Grants Collection for Elementary Statistics was created under a Round Four ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


Quantitative Skills And Reasoning (Armstrong), Patricia Brown, Joshua Lambert Jul 2017

Quantitative Skills And Reasoning (Armstrong), Patricia Brown, Joshua Lambert

Mathematics Grants Collections

This Grants Collection for Quantitative Skills and Reasoning was created under a Round Five ALG Textbook Transformation Grant.

Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process.

Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials:

  • Linked Syllabus
  • Initial Proposal
  • Final Report


A Privacy Preserving Framework For Rfid Based Healthcare Systems, Farzana Rahman, Anwarul A. Bhuiyan, Sheikh Iqbal Ahamed Jul 2017

A Privacy Preserving Framework For Rfid Based Healthcare Systems, Farzana Rahman, Anwarul A. Bhuiyan, Sheikh Iqbal Ahamed

Mathematics, Statistics and Computer Science Faculty Research and Publications

RFID (Radio Frequency IDentification) is anticipated to be a core technology that will be used in many practical applications of our life in near future. It has received considerable attention within the healthcare for almost a decade now. The technology’s promise to efficiently track hospital supplies, medical equipment, medications and patients is an attractive proposition to the healthcare industry. However, the prospect of wide spread use of RFID tags in the healthcare area has also triggered discussions regarding privacy, particularly because RFID data in transit may easily be intercepted and can be send to track its user (owner). In a …


A Phase Iii, Randomized, Multi-Center, Double Blind, Placebo Controlled Study Of Safety And Efficacy Of Lofexidine For Relief Of Symptoms In Individuals Undergoing Inpatient Opioid Withdrawal, Charles W. Gorodetzky, Sharon L. Walsh, Peter R. Martin, Andrew J. Saxon, Kristen L. Gullo, Kousick Biswas Jul 2017

A Phase Iii, Randomized, Multi-Center, Double Blind, Placebo Controlled Study Of Safety And Efficacy Of Lofexidine For Relief Of Symptoms In Individuals Undergoing Inpatient Opioid Withdrawal, Charles W. Gorodetzky, Sharon L. Walsh, Peter R. Martin, Andrew J. Saxon, Kristen L. Gullo, Kousick Biswas

Center on Drug and Alcohol Research Faculty Publications

Background: Lofexidine is an alpha-2-adrenergic receptor agonist approved in the United Kingdom (UK) for the treatment of opioid withdrawal symptoms. Lofexidine has demonstrated better efficacy than placebo for reducing opioid withdrawal symptoms in patients undergoing opioid withdrawal with less reported hypotension than clonidine.

Methods: Designed as an FDA registration trial, this 8-day, randomized, double-blind, placebo-controlled, parallel-group study in 264 patients dependent on short-acting opioids evaluated the efficacy of lofexidine hydrochloride in reducing withdrawal symptoms in patients undergoing opioid withdrawal. The primary efficacy measures were SOWS-Gossop on Day 3 and time-to-dropout. Secondary endpoints included the proportion of participants who were completers; …


Factor Based Statistical Arbitrage In The U.S. Equity Market With A Model Breakdown Detection Process, Seoungbyung Park Jul 2017

Factor Based Statistical Arbitrage In The U.S. Equity Market With A Model Breakdown Detection Process, Seoungbyung Park

Master's Theses (2009 -)

Many researchers have studied different strategies of statistical arbitrage to provide a steady stream of returns that are unrelated to the market condition. Among different strategies, factor-based mean reverting strategies have been popular and covered by many. This thesis aims to add value by evaluating the generalized pairs trading strategy and suggest enhancements to improve out-of-sample performance. The enhanced strategy generated the daily Sharpe ratio of 6.07% in the out-of-sample period from January 2013 through October 2016 with the correlation of -.03 versus S&P 500. During the same period, S&P 500 generated the Sharpe ratio of 6.03%. This thesis is …


Educational Magic Tricks Based On Error-Detection Schemes, Ronald I. Greenberg Jul 2017

Educational Magic Tricks Based On Error-Detection Schemes, Ronald I. Greenberg

Computer Science: Faculty Publications and Other Works

Magic tricks based on computer science concepts help grab student attention and can motivate them to delve more deeply. Error detection ideas long used by computer scientists provide a rich basis for working magic; probably the most well known trick of this type is one included in the CS Unplugged activities. This paper shows that much more powerful variations of the trick can be performed, some in an unplugged environment and some with computer assistance. Some of the tricks also show off additional concepts in computer science and discrete mathematics.


Evaluation Of Multiple Interventions Using A Stepped Wedge Design, Vivian H. Lyons, Lingyu Li, James Hughes, Ali Rowhani-Rahbar Jun 2017

Evaluation Of Multiple Interventions Using A Stepped Wedge Design, Vivian H. Lyons, Lingyu Li, James Hughes, Ali Rowhani-Rahbar

UW Biostatistics Working Paper Series

Background: Stepped wedge cluster randomized trials are a class of unidirectional crossover studies that have historically been limited to evaluating a single intervention. This design is especially suitable for pragmatic trials where the study feasibility can be improved with a phased introduction of the intervention. We examined variations of stepped wedge designs that would support evaluation of multiple interventions. Methods: We propose four different design variants for implementing a stepped wedge trial with two interventions: concurrent design, supplementation, replacement, and factorial designs. Analyses were conducted comparing the precision of the estimated intervention effects for the different designs. Results: Concurrent, …


Biomarker Combinations For Diagnosis And Prognosis In Multicenter Studies: Principles And Methods, Allison Meisner, Chirag R. Parikh, Kathleen F. Kerr Jun 2017

Biomarker Combinations For Diagnosis And Prognosis In Multicenter Studies: Principles And Methods, Allison Meisner, Chirag R. Parikh, Kathleen F. Kerr

UW Biostatistics Working Paper Series

Many investigators are interested in combining biomarkers to predict an outcome of interest or detect underlying disease. This endeavor is complicated by the fact that many biomarker studies involve data from multiple centers. Depending upon the relationship between center, the biomarkers, and the target of prediction, care must be taken when constructing and evaluating combinations of biomarkers. We introduce a taxonomy to describe the role of center and consider how a biomarker combination should be constructed and evaluated. We show that ignoring center, which is frequently done by clinical researchers, is often not appropriate. The limited statistical literature proposes using …


An Investigation Of The Accuracy Of Parallel Analysis For Determining The Number Of Factors In A Factor Analysis, Mandy Matsumoto Jun 2017

An Investigation Of The Accuracy Of Parallel Analysis For Determining The Number Of Factors In A Factor Analysis, Mandy Matsumoto

Mahurin Honors College Capstone Experience/Thesis Projects

Exploratory factor analysis is an analytic technique used to determine the number of factors in a set of data (usually items on a questionnaire) for which the factor structure has not been previously analyzed. Parallel analysis (PA) is a technique used to determine the number of factors in a factor analysis. There are a number of factors that affect the results of a PA: the choice of the eigenvalue percentile, the strength of the factor loadings, the number of variables, and the sample size of the study. Although PA is the most accurate method to date to determine which factors …


Mixture Models For Undiagnosed Prevalent Disease And Interval-Censored Incident Disease: Applications To A Cohort Assembled From Electronic Health Records., Li C Cheung, Qing Pan, Noorie Hyun, Mark Schiffman, Barbara Fetterman, Philip E Castle, Thomas Lorey, Hormuzd A Katki Jun 2017

Mixture Models For Undiagnosed Prevalent Disease And Interval-Censored Incident Disease: Applications To A Cohort Assembled From Electronic Health Records., Li C Cheung, Qing Pan, Noorie Hyun, Mark Schiffman, Barbara Fetterman, Philip E Castle, Thomas Lorey, Hormuzd A Katki

Epidemiology Faculty Publications

For cost-effectiveness and efficiency, many large-scale general-purpose cohort studies are being assembled within large health-care providers who use electronic health records. Two key features of such data are that incident disease is interval-censored between irregular visits and there can be pre-existing (prevalent) disease. Because prevalent disease is not always immediately diagnosed, some disease diagnosed at later visits are actually undiagnosed prevalent disease. We consider prevalent disease as a point mass at time zero for clinical applications where there is no interest in time of prevalent disease onset. We demonstrate that the naive Kaplan-Meier cumulative risk estimator underestimates risks at early …


Time Series Online Empirical Bayesian Kernel Density Segmentation: Applications In Real Time Activity Recognition Using Smartphone Accelerometer, Shuang Na Jun 2017

Time Series Online Empirical Bayesian Kernel Density Segmentation: Applications In Real Time Activity Recognition Using Smartphone Accelerometer, Shuang Na

USF Tampa Graduate Theses and Dissertations

Time series analysis has been explored by the researchers in many areas such, as statistical research, engineering applications, medical analysis, and finance study. To represent the data more efficiently, the mining process is supported by time series segmentation. Time series segmentation algorithm looks for the change points between two different patterns and develops a suitable model, depending on the data observed in such segment. Based on the issue of limited computing and storage capability, it is necessary to consider an adaptive and incremental online segmentation method. In this study, we propose an Online Empirical Bayesian Kernel Segmentation (OBKS), which combines …


Cybersecurity: Probabilistic Behavior Of Vulnerability And Life Cycle, Sasith Maduranga Rajasooriya Jun 2017

Cybersecurity: Probabilistic Behavior Of Vulnerability And Life Cycle, Sasith Maduranga Rajasooriya

USF Tampa Graduate Theses and Dissertations

Analysis on Vulnerabilities and Vulnerability Life Cycle is at the core of Cybersecurity related studies. Vulnerability Life Cycle discussed by S. Frei and studies by several other scholars have noted the importance of this approach. Application of Statistical Methodologies in Cybersecurity related studies call for a greater deal of new information. Using currently available data from National Vulnerability Database this study develops and presents a set of useful Statistical tools to be applied in Cybersecurity related decision making processes.

In the present study, the concept of Vulnerability Space is defined as a probability space. Relevant theoretical analyses are conducted and …


Marketing The Mountain State: A Large N Study Of User Engagement On Twitter, Kirk Richardson Jun 2017

Marketing The Mountain State: A Large N Study Of User Engagement On Twitter, Kirk Richardson

Capstone Projects – Politics and Government

Much of the evolving research on the use of social media in destination marketing emphasizes how information diffusion influences the reputational image of place. The present study uses Twitter data to focus on the relative differences in user engagement across discrete account types. Specifically, this is done to examine how the official destination marketing organization of Montana—the Montana Office of Tourism (MTOT)—performs relative to other account types. Several regression analyses conducted on Twitter data associated with an ongoing MTOT place branding campaign reveal that tweets sent from ‘official’ accounts are more likely to be retweeted, and are estimated to receive …


Cybersecurity: Stochastic Analysis And Modelling Of Vulnerabilities To Determine The Network Security And Attackers Behavior, Pubudu Kalpani Kaluarachchi Jun 2017

Cybersecurity: Stochastic Analysis And Modelling Of Vulnerabilities To Determine The Network Security And Attackers Behavior, Pubudu Kalpani Kaluarachchi

USF Tampa Graduate Theses and Dissertations

Development of Cybersecurity processes and strategies should take two main approaches. One is to develop an efficient and effective set of methodologies to identify software vulnerabilities and patch them before being exploited. Second is to develop a set of methodologies to predict the behavior of attackers and execute defending techniques based on attacking behavior. Managing of Vulnerabilities and analyzing them is directly related to the first approach. Developing of methodologies and models to predict the behavior of attackers is related to the second approach. Both these approaches are inseparably interconnected. Our effort in this study mainly focuses on developing useful …


A Microrna Signature Of Response To Erlotinib Is Descriptive Of Tgfβ Behaviour In Nsclc, Madeline J. Krentz Gober, James P. Collard, Katherine L. Thompson, Esther P. Black Jun 2017

A Microrna Signature Of Response To Erlotinib Is Descriptive Of Tgfβ Behaviour In Nsclc, Madeline J. Krentz Gober, James P. Collard, Katherine L. Thompson, Esther P. Black

Pharmaceutical Sciences Faculty Publications

Our previous work identified a 13-gene miRNA signature predictive of response to the epidermal growth factor receptor (EGFR) inhibitor, erlotinib, in Non-Small Cell Lung Cancer cell lines. Bioinformatic analysis of the signature showed a functional convergence on TGFβ canonical signalling. We hypothesized that TGFβ signalling controls expression of the miRNA genes comprising an erlotinib response signature in NSCLC. Western analysis revealed that TGFβ signalling via Smad2/3/4 occurred differently between erlotinib-resistant A549 and erlotinib- sensitive PC9 cells. We showed that TGFβ induced an interaction between Smad4 and putative Smad Binding Elements in PC9. However, qRT-PCR analysis showed that endogenous miR-140/141/200c expression …


Analysis Of A Potential A(H7n9) Influenza Pandemic Outbreak In The U.S., Walter A. Silva Sotillo Jun 2017

Analysis Of A Potential A(H7n9) Influenza Pandemic Outbreak In The U.S., Walter A. Silva Sotillo

USF Tampa Graduate Theses and Dissertations

This dissertation presents a collection of manuscripts that describe development of models and model implementation to analyze impact of potential A(H7N9) pandemic influenza outbreak in the U.S. Though this virus is still only animal-to-human transmittable, it has potential to become human-to-human transmittable and trigger a pandemic. This work is motivated by the negative impact on human lives that this virus has already caused in China, and is intended to support public health officials in preparing to protect U.S. population from a potential outbreak of pandemic scale.

An agent-based (AB) simulation model is used to replicate the social dynamics of the …


Safety Of Induced Sputum Collection In Children Hospitalized With Severe Or Very Severe Pneumonia., Andrea N Deluca, Laura L Hammitt, Julia Kim, Melissa M Higdon, Henry C Baggett, Daniel E Park, +Several Additional Authors Jun 2017

Safety Of Induced Sputum Collection In Children Hospitalized With Severe Or Very Severe Pneumonia., Andrea N Deluca, Laura L Hammitt, Julia Kim, Melissa M Higdon, Henry C Baggett, Daniel E Park, +Several Additional Authors

Epidemiology Faculty Publications

Background.: Induced sputum (IS) may provide diagnostic information about the etiology of pneumonia. The safety of this procedure across a heterogeneous population with severe pneumonia in low- and middle-income countries has not been described.

Methods.: IS specimens were obtained as part a 7-country study of the etiology of severe and very severe pneumonia in hospitalized childrenbefore, during, and after the procedure to record oxygen requirement, oxygen saturation, respiratory rate, consciousness level, and other evidence of clinical deterioration. Criteria for IS contraindications were predefined and serious adverse events (SAEs) were reported to ethics committees and a central safety monitor.

Results.: A …


Data Management And Data Quality In Perch, A Large International Case-Control Study Of Severe Childhood Pneumonia., Nora L Watson, Christine Prosperi, Amanda J Driscoll, Melissa M Higdon, Daniel E Park, Megan Sanza, Andrea N Deluca, Juliet O Awori, Doli Goswami, Emily Hammond, Lokman Hossain, Catherine Johnson, Alice Kamau, Locadiah Kuwanda, David P Moore, Omid Neyzari, Uma Onwuchekwa, David Parker, Patranuch Sapchookul Jun 2017

Data Management And Data Quality In Perch, A Large International Case-Control Study Of Severe Childhood Pneumonia., Nora L Watson, Christine Prosperi, Amanda J Driscoll, Melissa M Higdon, Daniel E Park, Megan Sanza, Andrea N Deluca, Juliet O Awori, Doli Goswami, Emily Hammond, Lokman Hossain, Catherine Johnson, Alice Kamau, Locadiah Kuwanda, David P Moore, Omid Neyzari, Uma Onwuchekwa, David Parker, Patranuch Sapchookul

Epidemiology Faculty Publications

The Pneumonia Etiology Research for Child Health (PERCH) study is the largest multicountry etiology study of pediatric pneumonia undertaken in the past 3 decades. The study enrolled 4232 hospitalized cases and 5325 controls over 2 years across 9 research sites in 7 countries in Africa and Asia. The volume and complexity of data collection in PERCH presented considerable logistical and technical challenges. The project chose an internet-based data entry system to allow real-time access to the data, enabling the project to monitor and clean incoming data and perform preliminary analyses throughout the study. To ensure high-quality data, the project developed …


Colonization Density Of The Upper Respiratory Tract As A Predictor Of Pneumonia-Haemophilus Influenzae, Moraxella Catarrhalis, Staphylococcus Aureus, And Pneumocystis Jirovecii., Daniel E Park, Henry C Baggett, Stephen R C Howie, Qiyuan Shi, Nora L Watson, W Abdullah Brooks, Perch Study Group Jun 2017

Colonization Density Of The Upper Respiratory Tract As A Predictor Of Pneumonia-Haemophilus Influenzae, Moraxella Catarrhalis, Staphylococcus Aureus, And Pneumocystis Jirovecii., Daniel E Park, Henry C Baggett, Stephen R C Howie, Qiyuan Shi, Nora L Watson, W Abdullah Brooks, Perch Study Group

Epidemiology Faculty Publications

Background.

There is limited information on the association between colonization density of upper respiratory tract colonizers and pathogen-specific pneumonia. We assessed this association for Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Pneumocystis jirovecii. Methods.

In 7 low- and middle-income countries, nasopharyngeal/oropharyngeal swabs from children with severe pneumonia and age-frequency matched community controls were tested using quantitative polymerase chain reaction (PCR). Differences in median colonization density were evaluated using the Wilcoxon rank-sum test. Density cutoffs were determined using receiver operating characteristic curves. Cases with a pathogen identified from lung aspirate culture or PCR, pleural fluid culture or …


Microscopic Analysis And Quality Assessment Of Induced Sputum From Children With Pneumonia In The Perch Study., David R Murdoch, Susan C Morpeth, Laura L Hammitt, Amanda J Driscoll, Daniel E Park, +Several Additional Authors Jun 2017

Microscopic Analysis And Quality Assessment Of Induced Sputum From Children With Pneumonia In The Perch Study., David R Murdoch, Susan C Morpeth, Laura L Hammitt, Amanda J Driscoll, Daniel E Park, +Several Additional Authors

Epidemiology Faculty Publications

Background.

It is standard practice for laboratories to assess the cellular quality of expectorated sputum specimens to check that they originated from the lower respiratory tract. The presence of low numbers of squamous epithelial cells (SECs) and high numbers of polymorphonuclear (PMN) cells are regarded as indicative of a lower respiratory tract specimen. However, these quality ratings have never been evaluated for induced sputum specimens from children with suspected pneumonia. Methods.

We evaluated induced sputum Gram stain smears and cultures from hospitalized children aged 1–59 months enrolled in a large study of community-acquired pneumonia. We hypothesized that a specimen representative …