Medicine and Health Sciences Commons^™

A Hybrid Model For Reducing Ecological Bias, Ruth Salway, Jon Wakefield

UW Biostatistics Working Paper Series

A major drawback of epidemiological ecological studies, in which the association between area-level summaries of risk and exposure are used to make inference about individual risk, is the difficulty in characterising within-area variability in exposure and confounder variables. To avoid ecological bias, samples of individual exposure/confounder data within each area are required. Unfortunately these may be difficult or expensive to obtain, particularly if large samples are required. In this paper we propose a new approach suitable for use with small samples. We combine a Bayesian non-parametric Dirichlet process prior with an estimating functions approach, and show that this model gives …

Health-Exposure Modelling And The Ecological Fallacy, Jon Wakefield, Gavin Shaddick

UW Biostatistics Working Paper Series

Recently there has been increased interest in modelling the association between aggregate disease counts and environmental exposures measured, for example via air pollution monitors, at point locations. This paper has two aims: first we develop a model for such data in order to avoid ecological bias; second we illustrate that modelling the exposure surface and estimating exposures may lead to bias in estimation of health effects. Design issues are also briefly considered, in particular the loss of information in moving from individual to ecological data, and the at-risk populations to consider in relation to the pollution monitor locations. The approach …

Dump Truck Driver Dies After Unintentional Release Of Asphalt, Kentucky Injury Prevention And Research Center

Fatality Case Reports--Motor Vehicle

On June 6, 2005 a 55-year-old male dump truck driver (Driver 1) died when he was buried waist deep in 400-degree Fahrenheit asphalt. Driver 1 stopped along the highway to help another dump truck driver (Driver 2), (both were independent truck drivers), who had experienced brake problems. As the two men were examining the pneumatic brake system at the rear of the disabled dump truck, the tailgate opened unexpectedly, spilling hot asphalt onto the decedent who was under the rear of the truck.

To prevent similar incidents, the following recommendations have been made:

Recommendation No. 1: Tailgate chains should always …

Ua12/2/1 College Heights Herald, Vol. 81, No. 23 [25], Wku Student Affairs

WKU Archives Records

WKU campus newspaper reporting campus, athletic and Bowling Green, Kentucky news. Articles in this issue:

• Leslie, Joey. More Students Tested During AIDS Day
• Hupman, Samantha. J-term More Popular than Anticipated
• Fontana, Alex. Student Government Association Proposes New Bicycles for Police
• Bosken, Nina. Students Dodge, Duck, Dive for Charity and Prizes – Special Olympics
• Richardson, Kelly. Kentucky Community Technical College System Requests Funding – KCTCS
• Taking the Next Step – Cultural Diversity
• Eoff, Allison. Pass on Adderall
• Gabler, R. XXX Ads Disappointing
• Williams, Suzanne. A Woman’s Heart
• Hupman, Samantha. Two Fights Reported on Hill
• Paul, Corey. Kwanzaa to Be Celebrated Today …

Redesigning Practice To Improve Care Delivery (Boston), Laura A. Dummit, Lisa Sprague

National Health Policy Forum

This site visit focused on how the practice of medicine is changing or can be changed to improve care delivery across the spectrum of patient populations. Regarded as a “medical Mecca,” Boston is home to the academic health centers and teaching hospitals where many of the nation’s physicians are trained. As a center of innovation, Boston prides itself on its high bar with respect to standards of care. Panels addressed the used of clinical information technology (IT) in the physician’s office, in the hospital, and community-wide. Participants observed how IT is being used to further the mission of community health …

History-Adjusted Marginal Structural Models To Estimate Time-Varying Effect Modification , Maya L. Petersen, Steven G. Deeks, Jeffrey N. Martin, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Much of epidemiology and clinical medicine is focused on the estimation of treatments or interventions administered over time. In such settings of longitudinal treatment, time-dependent confounding is often an important source of bias. Marginal structural models are a powerful tool for estimating the causal effect of a treatment using observational data, particularly when time-dependent confounding is present. Recent statistical work presented a generalization of marginal structural models, called history-adjusted marginal structural models. Unlike standard marginal structural models, history-adjusted marginal structural models can be used to estimate modification of treatment effects by time-varying covariates. Estimation of time-dependent causal effect modification is …

Aflatoxin Contamination Of Commercial Maize Products During An Outbreak Of Acute Aflatoxicosis In Eastern And Central Kenya, Karen E. Gieseker, Lauren Lewis, Mary Onsongo, Henry Njapau, Helen Schurz Rogers, George Luber, Stephanie Kieszak, Jack Nyamongo, Lorraine Backer, Abdikher Mohamud Dahiye, Ambrose Misore, Kevin Decock, Carol Rubin, Kenya Aflatoxicosis Investigation Group

Public Health Faculty Publications

n April 2004, one of the largest aflatoxicosis outbreaks occurred in rural Kenya, resulting in 317 cases and 125 deaths. Aflatoxin-contaminated homegrown maize was the source of the outbreak, but the extent of regional contamination and status of maize in commercial markets (market maize) were unknown. We conducted a cross-sectional survey to assess the extent of market maize contamination and evaluate the relationship between market maize aflatoxin and the aflatoxicosis outbreak. We surveyed 65 markets and 243 maize vendors and collected 350 maize products in the most affected districts. Fifty-five percent of maize products had aflatoxin levels greater than the …

Genotype-By-Sex Interaction In The Regulation Of High-Density Lipoprotein: Theframingham Heart Study, M.J. Mosher, L. J. Martin, L. A. Cupples, Q. Yang, T. D. Dyer, J. T. Williams, K. E. North

Anthropology Faculty and Staff Publications

Low levels of high-density lipoprotein (HDL) are widely documented as a risk factor for cardiovascular disease (CVD). Furthermore, there is marked sexual dimorphism in both HDL levels and the prevalence of CVD. However, the extent to which genetic factors contribute to such dimorphism has been largely unexplored. We examined the evidence for genotypeby- sex effects on HDL in a longitudinal sample of 1,562 participants from 330 families in the Framingham Heart Study at three times points corresponding approximately to 1971-1974, 1980-1983, and 1988-1991. Using a variance component method, we conducted a genome scan of HDL at each time point in …

What Is Comprehensive Sexuality Education Really All About? Perceptions Of Students Enrolled In An Undergraduate Human Sexuality Course, Eva Goldfarb

Department of Public Health Scholarship and Creative Works

The purpose of this study was to use qualitative evaluation techniques to explore the perceptions of students enrolled in undergraduate human sexuality classes regarding their expectations for the course as well as outcomes. One hundred forty-eight students were surveyed at the beginning and again at the end of the semester-long course. While pregnancy and STI prevention were considered important components of their courses, other outcomes associated with positive, healthy sexuality were given greater emphasis. Results suggest that while primary and secondary level sexuality education have been increasingly focused on abstinence-only education with a focus on pregnancy and STI reduction, this …

High Potency And Other Alcoholic Beverage Consumption Among Adolescents, Edessa C. Jobli, Heather S. Dore, Chudley Werch, Michele Johnson Moore

Public Health Faculty Research and Scholarship

This study examined the prevalence of high potency (liquor, malt liquor, fortified wine) and other alcoholic beverage consumption (beer, wine/wine coolers) among adolescents, the impact of gender and ethnicity, and the risk and protective factors that predicted consumption. A confidential survey revealed that, among eighth grade students, wine/wine coolers were the most popular alcoholic beverages, with the highest levels of lifetime use, and the greatest current frequency and quantity of use, followed closely by beer and liquor. Minor gender differences were found, as well as notable ethnic differences, in consumption. Intentions and attitudes were important predictors of use across beverages. …

Sources Of Variation In Nutrient Intakes Among Men In Shanghai, China, Hui Cai, Gong Yang, Yong-Bing Xiang, James R. Hébert, Da-Ke Liu, Wei Zheng, Xiao-Ou Shu

Faculty Publications

Background and objective: Random errors, from any source, will attenuate epidemiological risk estimates. Before we launched the Shanghai Men’s Health Study (SMHS), a large population-based cohort study investigating the diet–cancer association among Chinese men, a dietary calibration study was conducted among 96 men aged 40–75 years (mean age 56.5 years), with biweekly 24-hour dietary recalls (24HDRs) implemented over a 1-year period. Data from this study were analysed to evaluate the nature and magnitude of variances for intake of 26 nutrients among SMHS participants, to compare variance ratios of 26 nutrients among Chinese men and women and individuals in other studies, …

Are Specific Language Impairment And Dyslexia Distinct Disorders?, Hugh W. Catts, Suzanne M. Adlof, Tiffany Hogan, Susan Ellis Weismer

Faculty Publications

Purpose - The purpose of this study was to determine whether specific language impairment (SLI) and dyslexia are distinct developmental disorders.

Method - Study 1 investigated the overlap between SLI identified in kindergarten and dyslexia identified in 2nd, 4th, or 8th grades in a representative sample of 527 children. Study 2 examined phonological processing in a subsample of participants, including 21 children with dyslexia only, and 43 children with SLI only, 18 children with SLI and dyslexia, and 165 children with typical language/reading development. Measures of phonological awareness and nonword repetition were considered.

Results - Study 1 showed limited but …

Asthma Management Programs In Managed Care Organizations, Christine W. Hartmann Mss, Phd, Vittorio Maio Pharmd, Ms, Neil I. Goldfarb, Nicole M. Cobb Maom, David B. Nash

College of Population Health Faculty Papers

The aim of this work was to investigate how managed care organizations (MCOs) currently approach asthma treatment and management and to determine factors affecting asthma outcomes. A Web-based survey was administered to a national sample of 351 medical directors of MCOs to investigate the asthma management program components in their organizations as well as gaps and barriers in the management of patients with asthma. All 134 (38.2%) responding medical directors reported that their organizations monitor asthma patients. Plans use a variety of asthma management activities, including general member education (90%), member education by mail (87%), self-management education (85%), and provider …

Remote Physiological Monitoring: Clinical, Financial, And Behavioral Outcomes In A Heart Failure Population, Laurel R. Hudson Msn, Rn, G. Brent Hamar Dds, Mph, Patty Orr Rn, Edd, Jeffrey H. Johnson Bs, Amy Neftzger Ma, Richard S. Chung Md, Myra L. Williams Mph, William M. Gandy Edd, Albert Crawford Phd, Mba, Msis, Janice L. Clarke Rn, Bba, Neil I. Goldfarb

College of Population Health Faculty Papers

This article reports on the outcomes associated with remote physiological monitoring (RPM) conducted as part of a heart failure disease management program. Claims data, medical records, data transmission records, and survey results for 91 individuals ages 50–92 (mean 74 years) successfully completing a heart failure RPM program were analyzed for time periods before, during, and after the monitoring intervention. The program was associated with significant reductions in per member per month costs and emergency room and hospital utilization. More detailed analyses were performed for specific gender and age subgroups. Participant surveys indicated high levels of satisfaction, and improvements in self-perceived …

Intimate Partner Violence And Disabilities Among Women Attending Family Practice Clinics, Ann L. Coker, Paige H. Smith, Mary Kay Fadden

CRVAW Faculty Journal Articles

Purpose: To estimate the frequency and type of disabilities preventing work among those experiencing intimate partner violence (IPV) compared with those never experiencing IPV.

Methods: We used a large cross-sectional survey of women, ages 18–65, attending family practice clinics from 1997 through 1998. Participation included a 5–10-minute in-clinic survey assessing IPV experience and a longer telephone survey assessing health status and chronic disabilities that prevented work outside the home or housework.

Results: Of 1,152 eligible women surveyed, 54% experienced some type of IPV, and 24% were currently in a violent relationship. Women who had ever experienced IPV …

Medicare Advantage Snps: A New Opportunity For Integrated Care?, Christie Provost Peters

National Health Policy Forum

Medicare Advantage special needs plans (SNPs) are a new type of coordinated care plan established by the Medicare Prescription Drug, Improvement and Modernization Act. SNPs were created to encourage greater access to Medicare managed care for certain special needs populations: the institutionalized, persons dually eligible for Medicare and Medicaid, and the chronically ill. Some view SNPs as a new opportunity to integrate acute and long-term care services as well as Medicare and Medicaid financing. Others, however, question the degree to which full integration will become a widespread reality. This issue brief examines the SNP option and the promises and challenges …

Social Security Reform: What Are The Options?, Greg Shaw, Susan Swanlund, Tari Renner

Roundtables

Recorded in 2005, this Roundtable set the social security issue in the context of public opinion, strategies of the political parties, and changes in the Medicare program. The goal of the discussion was to help citizens understand the political and economic challenges confronting the efforts to reform social security.

A transcript of this discussion is available at the download link above and to the right of this page.

Effects Of Screening And Brief Intervention Training On Resident And Faculty Alcohol Intervention Behaviours: A Pre- Post-Intervention Assessment, J. Paul Seale, Sylvia Shellenberger, John M. Boltri, Ike S. Okosun, Barbara Barton

Public Health Faculty Publications

Background: Many hazardous and harmful drinkers do not receive clinician advice to reduce their drinking. Previous studies suggest under-detection and clinician reluctance to intervene despite awareness of problem drinking (PD). The Healthy Habits Project previously reported chart review data documenting increased screening and intervention with hazardous and harmful drinkers after training clinicians and implementing routine screening. This report describes the impact of the Healthy Habits training program on clinicians' rates of identification of PD, level of certainty in identifying PD and the proportion of patients given advice to reduce alcohol use, based on self-report data using clinician exit questionnaires.

Methods: …

Oral Contraceptive Use And Risk Of Breast Cancer Among Women With A Family History Of Breast Cancer: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

Family history of breast cancer is an established risk factor for breast cancer. In addition, there is evidence that oral contraceptive use may be associated with a moderate increase in breast cancer risk. The three cohort studies that have investigated the relationship between oral contraceptive use and breast cancer risk among women with a family history of breast cancer have yielded mixed results, possibly due to the relatively small sample sizes employed and/or differences in the selection of covariates for inclusion in multivariate models. Therefore, we examined the association between oral contraceptive use and breast cancer risk in a large …

Dump Truck Driver Crushed Between Trackhoe And Dump Truck, Kentucky Injury Prevention And Research Center

Fatality Case Reports--Motor Vehicle

On November 11, 2004, a 33-year-old male dump truck driver died when he was crushed between the driver’s side of the dump truck and the swinging counter-weight of an excavator (trackhoe). His dump truck became stuck in mud after the trackhoe loaded dirt into it so he walked to the on-site office and informed the owner. The owner located a bulldozer on site and drove it to the dump truck while the driver retrieved a chain from his personal pickup truck. The owner raised the blade so the driver could attach the chain to it. Raising the blade of the …

Population Intervention Models In Causal Inference, Alan E. Hubbard, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Marginal structural models (MSM) provide a powerful tool for estimating the causal effect of a] treatment variable or risk variable on the distribution of a disease in a population. These models, as originally introduced by Robins (e.g., Robins (2000a), Robins (2000b), van der Laan and Robins (2002)), model the marginal distributions of treatment-specific counterfactual outcomes, possibly conditional on a subset of the baseline covariates, and its dependence on treatment. Marginal structural models are particularly useful in the context of longitudinal data structures, in which each subject's treatment and covariate history are measured over time, and an outcome is recorded at …

Additive Hazards Models With Latent Treatment Effectiveness Lag Time, Ying Qing Chen, Charles A. Rohde, Mei-Cheng Wang

Johns Hopkins University, Dept. of Biostatistics Working Papers

In many clinical trials to evaluate treatment efficacy, it is believed that there may exist latent treatment effectiveness lag times after which medical procedure or chemical compound would be in full effect. In this article, semiparametric regression models are proposed and studied to estimate the treatment effect accounting for such latent lag times. The new models take advantage of the invariance property of the additive hazards model in marginalizing over random effects, so parameters in the models are easy to be estimated and interpreted, while the flexibility without specifying baseline hazard function is kept. Monte Carlo simulation studies demonstrate the …

Gauss-Seidel Estimation Of Generalized Linear Mixed Models With Application To Poisson Modeling Of Spatially Varying Disease Rates, Subharup Guha, Louise Ryan

Harvard University Biostatistics Working Paper Series

Generalized linear mixed models (GLMMs) provide an elegant framework for the analysis of correlated data. Due to the non-closed form of the likelihood, GLMMs are often fit by computational procedures like penalized quasi-likelihood (PQL). Special cases of these models are generalized linear models (GLMs), which are often fit using algorithms like iterative weighted least squares (IWLS). High computational costs and memory space constraints often make it difficult to apply these iterative procedures to data sets with very large number of cases.

This paper proposes a computationally efficient strategy based on the Gauss-Seidel algorithm that iteratively fits sub-models of the GLMM …

Cigarette Smoking And Risk Of Glioma: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

The etiology of glioma, the most commonly diagnosed malignant brain tumor among adults in the United States, is poorly understood. N‐nitroso compounds are known carcinogens, which are found in cigarette smoke and can induce gliomas in rats. On this basis, it has been hypothesized that cigarette smoking may be associated with an increased risk of glioma. We investigated the association between cigarette smoking and glioma risk in the National Breast Screening Study, which included 89,835 Canadian women aged 40–59 years at recruitment between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths …

Cigarette Smoking And Risk Of Glioma: A Prospective Cohort Study, Stephanie A. Navarro Silvera, Anthony B. Miller, Thomas E. Rohan

Department of Public Health Scholarship and Creative Works

The etiology of glioma, the most commonly diagnosed malignant brain tumor among adults in the United States, is poorly understood. N‐nitroso compounds are known carcinogens, which are found in cigarette smoke and can induce gliomas in rats. On this basis, it has been hypothesized that cigarette smoking may be associated with an increased risk of glioma. We investigated the association between cigarette smoking and glioma risk in the National Breast Screening Study, which included 89,835 Canadian women aged 40–59 years at recruitment between 1980 and 1985. Linkages to national cancer and mortality databases yielded data on cancer incidence and deaths …

Computational Techniques For Spatial Logistic Regression With Large Datasets, Christopher J. Paciorek, Louise Ryan

Harvard University Biostatistics Working Paper Series

In epidemiological work, outcomes are frequently non-normal, sample sizes may be large, and effects are often small. To relate health outcomes to geographic risk factors, fast and powerful methods for fitting spatial models, particularly for non-normal data, are required. We focus on binary outcomes, with the risk surface a smooth function of space. We compare penalized likelihood models, including the penalized quasi-likelihood (PQL) approach, and Bayesian models based on fit, speed, and ease of implementation.

A Bayesian model using a spectral basis representation of the spatial surface provides the best tradeoff of sensitivity and specificity in simulations, detecting real spatial …

Evaluation Of African-American And White Racial Classification In A Surveillance, Epidemiology, And End Results Cancer Registry, Diva A. Patel, Alicia Knowles, Ann G. Schwartz, Kendra Schwartz

FMPHS Faculty Publications

Objectives: This study evaluated the validity of registry-reported race for individuals who participated in research studies conducted since 1980 through the Metropolitan Detroit Cancer Surveillance System (MDCSS), a Surveillance, Epidemiology, and End Results (SEER) Program registry.

Methods: 5329 individuals who self-identified as African American or White and were classified in the MDCSS registry as African American or White were included. Self-identified and registry-reported race were compared, and associations between demographics and racial misclassification were examined.

Results: Most self-identified African Americans and Whites were correctly classified (sensitivity= 98.5%, specificity=99.7%). Males were two times more likely to be misclassified than females [odds …

Estimation And Projection Of Indicence And Prevalence Based On Doubly Truncated Data With Application To Pharmacoepidemiological Databases, Henrik Stovring, Mei-Cheng Wang

Johns Hopkins University, Dept. of Biostatistics Working Papers

Incidences of disease are of primary interest in any epidemiological analysis of disease spread in general populations. Ordinary estimates obtained from follow-up of an initially non-diseased cohort are costly, and so such estimates are not routinely available. In contrast, routine registers exist for many diseases with data on all detected cases within a given calendar time period, but lacking information on non-diseased. In the present work we show how this type of data supplemented with data on the past birth process can be analyzed to yield age specific incidence estimates as well as lifetime prevalence. A non-parametric model is studied …

Is The Number Of Sick Persons In A Cohort Constant Over Time?, Paula Diehr, Ann Derleth, Anne Newman, Liming Cai

UW Biostatistics Working Paper Series

Objectives: To estimate the number of persons in a cohort who are sick, over time.

Methods: We calculated the number of sick persons in the Cardiovascular Health Study (CHS), a cohort study of older adults followed up to 14 years, using eight definitions of “healthy” and “sick”. We projected the number in each health state over time for a birth cohort.

Results: The number of sick persons in CHS was approximately constant for 14 years, for all definitions of “sick”. The estimated number of sick persons in the birth cohort was approximately constant from ages 55-75, after which it decreased. …

Abortion: The Reality For Women Of Praia Grande, Anna Tawse

Independent Study Project (ISP) Collection

Under Brazilian law, abortions are prohibited in all cases except for pregnancies resulting from rape or sexual violence and pregnancies which present possible death or harm to the mother. Upon a closer look, however, it is obvious that regardless of the illegality, Brazilian women are getting abortions. In light of this, I conducted a research project to uncover more about the reality that Brazilian women, specifically located in Praia Grande (a small community on Ilha de Mare off the coast of Salvador), face given the simultaneous existence of the two situations listed above (which I refer to as the “abortion …