Public Health Commons^™

The Association Of Blood Type On The Five Factors Of Personality In Chinese Adolescents, Kunher Wu

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to identify the number of personality factors in Chinese adolescents using the Chinese Revised NEO Personality Inventory (NEO-PI-R) and to determine whether blood type is associated with personality. It is widely accepted by psychologists that the five-factor model can provide an adequate representation of adult personality dimensions, but there is less agreement on the number of factors observable in adolescence. A total of 3,396 11^th graders from the city of Kaohsiung, Taiwan completed the Chinese NEO-PI-R. Principle component analysis with varimax rotation showed five factors of personality in these Taiwanese adolescents, which clearly …

Seasonal Analyses Of Air Pollution And Mortality In 100 U.S. Cities, Roger D. Peng, Francesca Dominici, Roberto Pastor-Barriuso, Scott L. Zeger, Jonathan M. Samet

Johns Hopkins University, Dept. of Biostatistics Working Papers

Time series models relating short-term changes in air pollution levels to daily mortality counts typically assume that the effects of air pollution on the log relative rate of mortality do not vary with time. However, these short-term effects might plausibly vary by season. Changes in the sources of air pollution and meteorology can result in changes in characteristics of the air pollution mixture across seasons. The authors develop Bayesian semi-parametric hierarchical models for estimating time-varying effects of pollution on mortality in multi-site time series studies. The methods are applied to the updated National Morbidity and Mortality Air Pollution Study database …

On Corrected Score Approach For Proportional Hazards Model With Covariate Measurement Error, Xiao Song, Yijian Huang

UW Biostatistics Working Paper Series

In the presence of covariate measurement error with the proportional hazards model, several functional modeling methods have been proposed. These include the conditional score estimator (Tsiatis and Davidian, 2001), the parametric correction estimator (Nakamura, 1992) and the nonparametric correction estimator (Huang and Wang, 2000, 2003) in the order of weaker assumptions on the error. Although they are all consistent, each suffers from potential difficulties with small samples and substantial measurement error. In this article, upon noting that the conditional score and parametric correction estimators are asymptotically equivalent in the case of normal error, we investigate their relative finite sample performance …

Causal Inference In Hybrid Intervention Trials Involving Treatment Choice, Qi Long, Rod Little, Xihong Lin

The University of Michigan Department of Biostatistics Working Paper Series

Randomized allocation of treatments is a cornerstone of experimental design, but has drawbacks when a limited set of individuals are willing to be randomized, or the act of randomization undermines the success of the treatment. Choice-based experimental designs allow a subset of the participants to choose their treatments. We discuss here causal inferences for experimental designs where some participants are randomly allocated to treatments and others receive their treatment preference. This paper was motivated by the “Women Take Pride” (WTP) study (Janevic et al., 2001), a doubly randomized preference trail (DRPT) to assess behavioral interventions for women with heart disease. …

Individualized Predictions Of Disease Progression Following Radiation Therapy For Prostate Cancer., Jeremy Taylor, Menggang Yu, Howard M. Sandler

The University of Michigan Department of Biostatistics Working Paper Series

Background: Following treatment for localized prostate cancer, men are monitored with serial PSA measurements. Refining the predictive value of post-treatment PSA determinations may add to clinical management and we have developed a model that predicts for an individual patient future PSA values and estimates the time to future clinical recurrence.

Methods: Data from 934 patients treated for prostate cancer between 1987 and 2000 were used to develop a comprehensive statistical model to fit the clinical recurrence events and pattern of PSA data. A logistic regression model was used for the probability of cure, non-linear hierarchical mixed models were used for …

Overlap Bias In The Case-Crossover Design, With Application To Air Pollution Exposures, Holly Janes, Lianne Sheppard, Thomas Lumley

UW Biostatistics Working Paper Series

The case-crossover design uses cases only, and compares exposures just prior to the event times to exposures at comparable control, or “referent” times, in order to assess the effect of short-term exposure on the risk of a rare event. It has commonly been used to study the effect of air pollution on the risk of various adverse health events. Proper selection of referents is crucial, especially with air pollution exposures, which are shared, highly seasonal, and often have a long term time trend. Hence, careful referent selection is important to control for time-varying confounders, and in order to ensure that …

Epidemiologic And Environmental Investigation Of A Recreational Water Outbreak Caused By Two Genotypes Of Cryptosporidium Parvum In Ohio In 2000, Els Mathieu, Deborah A. Levy, Fran Veverka, Mary-Kay Parrish, John Sarisky, Nancy Shapiro, Stephanie Johnston, Thomas Handzel, Allen Hightower, Lihua Xiao, Yeuk-Mui Lee, Steve York, Michael Arrowood, Robin Lee, Jeffrey L. Jones

Journal Articles: Epidemiology

In August 2000, the Ohio Department of Health requested assistance to investigate a cryptosporidiosis outbreak with more than 700 clinical case-patients. An epidemiologic and environmental investigation was conducted. Stool specimens, pool water, and sand filter samples were analyzed. A community-based case-control study showed that the main risk factor was swimming in pool A (odds ratio [OR] = 42, 95% confidence interval [CI] = 12.3-144.9). This was supported by results of polymerase chain reaction (PCR) analysis, which showed the presence of both the human and bovine genotypes of Cryptosporidium parvum in case-patients and samples from the filter of pool A. A …

Did A Severe Flood In The Midwest Cause An Increase In The Incidence Of Gastrointestinal Symptoms?, Timothy J. Wade, Sukhminder K. Sandhu, Deborah A. Levy, Sherline Lee, Mark W. Lechevallier, Louis Katz, John M. Colford

Journal Articles: Epidemiology

Severe flooding occurred in the midwestern United States in 2001. Since November 2000, coincidentally, data on gastrointestinal symptoms had been collected for a drinking water intervention study in a community along the Mississippi River that was affected by the flood. After the flood had subsided, the authors asked these subjects (n = 1,110) about their contact with floodwater. The objectives of this investigation were to determine whether rates of gastrointestinal illness were elevated during the flood and whether contact with floodwater was associated with increased risk of gastrointestinal illness. An increase in the incidence of gastrointestinal symptoms during the flood …

Sars Surveillance During Emergency Public Health Response, United States, March-July 2003, Stephanie J. Schrag, John T. Brooks, Chris Van Beneden, Umesh D. Parashar, Patricia M. Griffin, Larry J. Anderson, William J. Bellini, Robert F. Benson, Dean D. Erdman, Alexander Klimov, Thomas G. Ksiazek, Teresa C. T. Peret, Deborah F. Talkington, W. Lanier Thacker, Maria L. Tondella, Jacquelyn S. Sampson, Allen W. Hightower, Dale F. Nordenberg, Brian D. Plikaytis, Ali S. Khan, Nancy E. Rosenstein, Tracee A. Treadwell, Cynthia G. Whitney, Anthony E. Fiore, Tonji M. Durant, Joseph F. Perz, Annemarie Wasley, Daniel Feikin, Joy L. Herndon, William A. Bower, Barbara W. Klibourn, Deborah A. Levy, Victor G. Coronado, Joanna Buffington, Clare A. Dykewicz, Rima F. Khabbaz, Mary E. Chamberland

Journal Articles: Epidemiology

In response to the emergence of severe acute respiratory syndrome (SARS), the United States established national surveillance using a sensitive case definition incorporating clinical, epidemiologic, and laboratory criteria. Of 1,460 unexplained respiratory illnesses reported by state and local health departments to the Centers for Disease Control and Prevention from March 17 to July 30, 2003, a total of 398 (27%) met clinical and epidemiologic SARS case criteria. Of these, 72 (18%) were probable cases with radiographic evidence of pneumonia. Eight (2%) were laboratory-confirmed SARS-coronavirus (SARS-CoV) infections, 206 (52%) were SARS-CoV negative, and 184 (46%) had undetermined SARS-CoV status because of …

Surveillance For Waterborne-Disease Outbreaks Associated With Drinking Water--United States, 2001-2002, Brian G. Blackburn, Gunther F. Craun, Jonathan S. Yoder, Vincent Hill, Rebecca L. Calderon, Nora Chen, Sherline H. Lee, Deborah A. Levy, Michael J. Beach

Journal Articles: Epidemiology

PROBLEM/CONDITION: Since 1971, CDC, the U.S. Environmental Protection Agency, and the Council of State and Territorial Epidemiologists have maintained a collaborative surveillance system for collecting and periodically reporting data related to occurrences and causes of waterborne-disease outbreaks (WBDOs). This surveillance system is the primary source of data concerning the scope and effects of waterborne disease outbreaks on persons in the United States.

REPORTING PERIOD COVERED: This summary includes data on WBDOs associated with drinking water that occurred during January 2001-December 2002 and on three previously unreported outbreaks that occurred during 2000.

DESCRIPTION OF SYSTEM: Public health departments in the states, …

Cardiovascular Disease Risk Factor Profile Of African American College Freshmen, Theodosha S. Gilliard

MUSC Theses and Dissertations

Background: Rates of CVD are higher among African Americans compared to whites and natives of South Carolina and the Southeast compared to non-natives. Obesity, a CVD risk factor, is also known to be more prevalent in African Americans compared to whites. Ethnic differences in body image are thought to play a role in the higher rates of obesity among African Americans compared to whites. This study investigated the prevalence of CVD risk factors and body image in an at risk population, African American adolescents primarily from the state of South Carolina. Research Design and Methods: Students were given a Health …

Surveillance For Waterborne-Disease Outbreaks Associated With Recreational Water--United States, 2001-2002, Jonathan S. Yoder, Brian G. Blackburn, Gunther F. Craun, Vincent Hill, Deborah A. Levy, Nora Chen, Sherline H. Lee, Rebecca L. Calderon, Michael J. Beach

Journal Articles: Epidemiology

PROBLEM/CONDITION: Since 1971, CDC, the U.S. Environmental Protection Agency, and the Council of State and Territorial Epidemiologists have maintained a collaborative surveillance system for collecting and periodically reporting data related to occurrences and causes of waterborne-disease outbreaks (WBDOs) related to drinking water; tabulation of recreational water-associated outbreaks was added to the surveillance system in 1978. This surveillance system is the primary source of data concerning the scope and effects of waterborne disease outbreaks on persons in the United States.

REPORTING PERIOD COVERED: This summary includes data on WBDOs associated with recreational water that occurred during January 2001-December 2002 and on …

Body Image And Attitudes Toward Obesity In College Students, Sarah Rebecca Goodwin

Theses and Dissertations

The current study was conducted in order to examine the impact of ethnicity on gender differences in body type preferences and perceptions and add to the literature examining racial differences in body type preferences and perceptions. The current study was an expansion of one by Gipson et al conducted at a historically Black university in 2004, in which responses and BMI measurements of 191 college students were examined for associations between BMI and gender, and body image and attitudes toward obesity. For the current study the sample of 176 college students enrolled at Virginia Commonwealth University, an ethnically diverse institution, …

Obesity And Health Status Among Urban Vs. Suburban Elderly In Philadelphia And Surrounding Counties, Ockidde Dufayne Harris

Theses and Dissertations

Obesity is a dangerous health condition affecting approximately 30% of all Americans and can be attributed to 300,000 deaths a year. Obesity has been found to disproportionately affect Blacks, Latinos, and those with lower SES. Although obesity is a problem for all age groups, its prevalence is highest among those 60-74 years of age. Studies have shown that there is an association between obesity and chronic conditions such as cardiovascular disease, arthritis, cancers, and type-2 diabetes. According to the Centers for Disease Control, chronic health conditions affect 80% of all elderly persons, many times limiting function and decreasing quality of …

Uncertainty And The Value Of Diagnostic Information With Application To Axillary Lymph Node Dissection In Breast Cancer, Giovanni Parmigiani

Johns Hopkins University, Dept. of Biostatistics Working Papers

In clinical decision making, it is common to ask whether, and how much, a diagnostic procedure is contributing to subsequent treatment decisions. Statistically, quantification of the value of the information provided by a diagnostic procedure can be carried out using decision trees with multiple decision points, representing both the diagnostic test and the subsequent treatments that may depend on the test's results. This article investigates probabilistic sensitivity analysis approaches for exploring and communicating parameter uncertainty in such decision trees. Complexities arise because uncertainty about a model's inputs determines uncertainty about optimal decisions at all decision nodes of a tree. We …

Survival Model Predictive Accuracy And Roc Curves, Patrick Heagerty, Yingye Zheng

UW Biostatistics Working Paper Series

The predictive accuracy of a survival model can be summarized using extensions of the proportion of variation explained by the model, or R^2, commonly used for continuous response models, or using extensions of sensitivity and specificity which are commonly used for binary response models.

In this manuscript we propose new time-dependent accuracy summaries based on time-specific versions of sensitivity and specificity calculated over risk sets. We connect the accuracy summaries to a previously proposed global concordance measure which is a variant of Kendall's tau. In addition, we show how standard Cox regression output can be used to obtain estimates of …

Time-Series Studies Of Particulate Matter, Michelle L. Bell, Jonathan M. Samet, Francesca Dominici

Johns Hopkins University, Dept. of Biostatistics Working Papers

Studies of air pollution and human health have evolved from descriptive studies of the early phenomena of large increases in adverse health effects following extreme air pollution episodes, to time-series analyses and the development of sophisticated regression models. In fact, advanced statistical methods are necessary to address the many challenges inherent in the detection of a small pollution risk in the presence of many confounders. This paper reviews the history, methods, and findings of the time-series studies estimating health risks associated with short-term exposure to particulate matter, though much of the discussion is applicable to epidemiological studies of air pollution …

A Corrected Pseudo-Score Approach For Additive Hazards Model With Longitudinal Covariates Measured With Error, Xiao Song, Yijian Huang

UW Biostatistics Working Paper Series

In medical studies, it is often of interest to characterize the relationship between a time-to-event and covariates, not only time-independent but also time-dependent. Time-dependent covariates are generally measured intermittently and with error. Recent interests focus on the proportional hazards framework, with longitudinal data jointly modeled through a mixed effects model. However, approaches under this framework depend on the normality assumption of the error, and might encounter intractable numerical difficulties in practice. This motivates us to consider an alternative framework, that is, the additive hazards model, under which little has been done when time-dependent covariates are measured with error. We propose …

Decreasing Barriers For Teens: Evaluation Of A New Teenage Pregnancy Prevention Strategy In School-Based Clinics, Abbey C. Sidebottom, Amanda Birnbaum, Sarah S. Nafstad

Department of Public Health Scholarship and Creative Works

Sidebottom et al seek to evaluate the effects of the change in distribution systems on students' receipt of requested contraceptives and demand for contraceptive school-based clinics (SBC). The result of the study reveals that the average number of requests per student was higher under the voucher system, possibly as a consequence of expires vouchers resulting in repeated requests. The findings also suggest that SBCs could go a step further in reducing adolescents' barriers to accessing contraceptives by adopting an on-site direct delivery system..

Cross-Calibration Of Stroke Disability Measures: Bayesian Analysis Of Longitudinal Ordinal Categorical Data Using Negative Dependence, Giovanni Parmigiani, Heidi W. Ashih, Gregory P. Samsa, Pamela W. Duncan, Sue Min Lai, David B. Matchar

Johns Hopkins University, Dept. of Biostatistics Working Papers

It is common to assess disability of stroke patients using standardized scales, such as the Rankin Stroke Outcome Scale (RS) and the Barthel Index (BI). The Rankin Scale, which was designed for applications to stroke, is based on assessing directly the global conditions of a patient. The Barthel Index, which was designed for general applications, is based on a series of questions about the patient’s ability to carry out 10 basis activities of daily living. As both scales are commonly used, but few studies use both, translating between scales is important in gaining an overall understanding of the efficacy of …

An Extended General Location Model For Causal Inference From Data Subject To Noncompliance And Missing Values, Yahong Peng, Rod Little, Trivellore E. Raghuanthan

The University of Michigan Department of Biostatistics Working Paper Series

Noncompliance is a common problem in experiments involving randomized assignment of treatments, and standard analyses based on intention-to treat or treatment received have limitations. An attractive alternative is to estimate the Complier-Average Causal Effect (CACE), which is the average treatment effect for the subpopulation of subjects who would comply under either treatment (Angrist, Imbens and Rubin, 1996, henceforth AIR). We propose an Extended General Location Model to estimate the CACE from data with non-compliance and missing data in the outcome and in baseline covariates. Models for both continuous and categorical outcomes and ignorable and latent ignorable (Frangakis and Rubin, 1999) …

Temporal Stability And Geographic Variation In Cumulative Case Fatality Rates And Average Doubling Times Of Sars Epidemics, Alison P. Galvani, Xiudong Lei, Nicholas P. Jewell

U.C. Berkeley Division of Biostatistics Working Paper Series

We analyze temporal stability and geographic trends in cumulative case fatality rates and average doubling times of severe acute respiratory syndrome (SARS). In part, we account for correlations between case fatality rates and doubling times through differences in control measures. We discuss factors that may alter future estimates of case fatality rates. We also discuss reasons for heterogeneity in doubling times among countries and the implications for the control of SARS in different countries and parameterization of epidemic models.

Identifying Target Populations For Screening Or Not Screening Using Logic Regression, Holly Janes, Margaret S. Pepe, Charles Kooperberg, Polly Newcomb

UW Biostatistics Working Paper Series

Colorectal cancer remains a significant public health concern despite the fact that effective screening procedures exist and that the disease is treatable when detected at early stages. Numerous risk factors for colon cancer have been identified, but none are very predictive alone. We sought to determine whether there are certain combinations of risk factors that distinguish well between cases and controls, and that could be used to identify subjects at particularly high or low risk of the disease to target screening. Using data from the Seattle site of the Colorectal Cancer Family Registry (C-CFR), we fit logic regression models to …

Improved Confidence Intervals For The Sensitivity At A Fixed Level Of Specificity Of A Continuous-Scale Diagnostic Test, Xiao-Hua Zhou, Gengsheng Qin

UW Biostatistics Working Paper Series

For a continuous-scale test, it is an interest to construct a confidence interval for the sensitivity of the diagnostic test at the cut-off that yields a predetermined level of its specificity (eg. 80%, 90%, or 95%). IN this paper we proposed two new intervals for the sensitivity of a continuous-scale diagnostic test at a fixed level of specificity. We then conducted simulation studies to compare the relative performance of these two intervals with the best existing BCa bootstrap interval, proposed by Platt et al. (2000). Our simulation results showed that the newly proposed intervals are better than the BCa bootstrap …

A Bootstrap Confidence Interval Procedure For The Treatment Effect Using Propensity Score Subclassification, Wanzhu Tu, Xiao-Hua Zhou

UW Biostatistics Working Paper Series

In the analysis of observational studies, propensity score subclassification has been shown to be a powerful method for adjusting unbalanced covariates for the purpose of causal inferences. One practical difficulty in carrying out such an analysis is to obtain a correct variance estimate for such inferences, while reducing bias in the estimate of the treatment effect due to an imbalance in the measured covariates. In this paper, we propose a bootstrap procedure for the inferences concerning the average treatment effect; our bootstrap method is based on an extension of Efron’s bias-corrected accelerated (BCa) bootstrap confidence interval to a two-sample problem. …

Application Of The Traditional Epidemiological Model To Predict Occupational Injury Rates In Manufacturing Industries, Gary A. Morris

Health Services Research Dissertations

This study was designed to test the usefulness of the Traditional Epidemiological Model of disease causation in modeling occupational injury rates and the presence of occupational illness in the manufacturing industry. More specifically, this research involved use of the agent, host, and environment constructs of the Traditional Epidemiological Model to examine the effects of five environmental-related workplace health and safety practices on occupational injury and illness. Data from the National Occupational Exposure Survey (NOES), conducted by the National Institute for Occupational Safety and Health (NIOSH) in 1981–1983, were used to ascertain the presence of specific workplace characteristics and to calculate …

Estimating The Accuracy Of Polymerase Chain Reaction-Based Tests Using Endpoint Dilution, Jim Hughes, Patricia Totten

UW Biostatistics Working Paper Series

PCR-based tests for various microorganisms or target DNA sequences are generally acknowledged to be highly "sensitive" yet the concept of sensitivity is ill-defined in the literature on these tests. We propose that sensitivity should be expressed as a function of the number of target DNA molecules in the sample (or specificity when the target number is 0). However, estimating this "sensitivity curve" is problematic since it is difficult to construct samples with a fixed number of targets. Nonetheless, using serially diluted replicate aliquots of a known concentration of the target DNA sequence, we show that it is possible to disentangle …

Political Authority And Social Cognitions On The War On Terrorism With Global Reach: Airport Security, Terrorism Contingent On A United States-Led Attack On Iraq, Smallpox Vaccinations, Ibpp Editor

International Bulletin of Political Psychology

This article presents analyses of three common social cognitions embraced by many representatives of political authority concerning aspects of the war on terrorism with global reach.

The Role Of Meat, Poultry, And Fish Consumption In The Occurrence Of Rheumatoid And Other Forms Of Arthritis, Asnake Hailu

Loma Linda University Electronic Theses, Dissertations & Projects

Rheumatoid arthritis and other forms of arthritis or rheumatism are now the leading cause of disability in the United States. The etiology and pathogenesis are less understood and available treatment options are not always satisfactory. This dissertation measures the prevalence and cumulative incidence of rheumatoid arthritis and other forms of arthritis or rheumatism, and examines any associations with current and lifetime consumption of meat, poultry, and fish (meat) using the Adventist Health Study and the Adventist Mortality Study databases. From these databases, it was possible to reconstruct a prospective cohort, obtain self-reported information on demographic characteristics, arthritis, rheumatoid arthritis, other …

Analysis Of Longitudinal Marginal Structural Models , Jennifer F. Bryan, Zhuo Yu, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In this article we construct and study estimators of the causal effect of a time-dependent treatment on survival in longitudinal studies. We employ a particular marginal structural model (MSM), and follow a general methodology for constructing estimating functions in censored data models. The inverse probability of treatment weighted (IPTW) estimator is used as an initial estimator and the corresponding treatment-orthogonalized, one-step estimator is consistent and asymptotically linear when the treatment mechanism is consistently estimated. We extend these methods to handle informative censoring. A simulation study demonstrates that the the treatment-orthogonalized, one-step estimator is superior to the IPTW estimator in terms …