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Medical Biomathematics and Biometrics Commons™

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2002

Articles 1 - 8 of 8

Full-Text Articles in Medical Biomathematics and Biometrics

Quantitative Evaluation Of Hiv Preventon Programs, Edward Kaplan, Ron Brookmeyer Nov 2002

Quantitative Evaluation Of Hiv Preventon Programs, Edward Kaplan, Ron Brookmeyer

Ron Brookmeyer

How successful are HIV prevention programs? Which HIV prevention programs are most cost effective? Which programs are worth expanding and which should be abandoned altogether? This book addresses the quantitative evaluation of HIV prevention programs, assessing for the first time several different quantitative methods of evaluation

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Prevention Of Inhalational Anthrax In The U.S. Outbreak, Ron Brookmeyer, Natalie Blades Nov 2002

Prevention Of Inhalational Anthrax In The U.S. Outbreak, Ron Brookmeyer, Natalie Blades

Ron Brookmeyer

No abstract provided.

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A Bayesian Analysis Involving Colonic Crypt Structure And Coordinated Response To Carcinogens Incorporating Missing Crypts, Jeffrey S. Morris, Naisyin Wang, Joanne R. Lupton, Robert S. Chapkin, Nancy D. Turner, Mee-Young Hong, Raymond J. Carroll Sep 2002

A Bayesian Analysis Involving Colonic Crypt Structure And Coordinated Response To Carcinogens Incorporating Missing Crypts, Jeffrey S. Morris, Naisyin Wang, Joanne R. Lupton, Robert S. Chapkin, Nancy D. Turner, Mee-Young Hong, Raymond J. Carroll

Jeffrey S. Morris

This paper is concerned with modeling the architecture of colonic crypts and the implications of this modeling for understanding possible coordinated response of carcinogen–induced DNA damage between various regions of the colon. The methods we develop to address these two issues are applied to a particular important example in colon carcinogenesis. We cast the problem as an unusual and not previously studied hierarchical mixed-effects model characterized by completely missing covariates in units at a structurally base level, except for some randomly selected units. Information concerning the missing covariates is available through certain known ordering constraints and surrogate measures. Our methods …

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The Blups Are Not “Best” When It Comes To Bootstrapping, Jeffrey S. Morris May 2002

The Blups Are Not “Best” When It Comes To Bootstrapping, Jeffrey S. Morris

Jeffrey S. Morris

In the setting of mixed models, some researchers may construct a semiparametric bootstrap by sampling from the best linear unbiased predictor residuals. This paper demonstrates both mathematically and by simulation that such a bootstrap will consistently underestimate the variation in the data in finite samples.

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Special Article: Outline On Status Of Post-9/11 Aviation Security Initiatives, Part I, Ibpp Editor May 2002

Special Article: Outline On Status Of Post-9/11 Aviation Security Initiatives, Part I, Ibpp Editor

International Bulletin of Political Psychology

This article provides a commentary in an outline format on post-9/11 aviation security initiatives within the United States (US).

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The Aging And Dying Processes And The Health Of Older Adults, Paula Diehr Mar 2002

The Aging And Dying Processes And The Health Of Older Adults, Paula Diehr

Paula Diehr

It is difficult to distinguish changes in health due to aging from those related to dying, because the two processes are highly related. Some potentially treatable conditions may mistakenly be dismissed as due to old age. The goal of this article was to examine the relationships of aging and of dying to changes in 10 health-related variables: self-rated health, depression, ADLs, IADLs, minimental state examination, body mass index, blocks walked per week, bed days, hospitalization, and walking speed (all coded so that higher values were better). We used longitudinal data from the Cardiovascular Health Study to estimate the changes in …

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The Importance Of The Normality Assumption In Large Public Health Data Sets, Paula Diehr, Thomas Lumley Jan 2002

The Importance Of The Normality Assumption In Large Public Health Data Sets, Paula Diehr, Thomas Lumley

Paula Diehr

It is widely but incorrectly believed that the t-test and linear regression are valid only for Normally distributed outcomes. The t-test and linear regression compare the mean of an outcome variable for different subjects. While these are valid even in very small samples if the outcome variable is Normally distributed, their major usefulness comes from the fact that in large samples they are valid for any distribution. We demonstrate this validity by simulation in extremely non-Normal data. We discuss situations in which in other methods such as the Wilcoxon rank sum test and ordinal logistic regression (proportional odds model) have …

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Weight-Modification Trials In Older Adults: What Should The Outcome Measure Be?, Paula Diehr Jan 2002

Weight-Modification Trials In Older Adults: What Should The Outcome Measure Be?, Paula Diehr

Paula Diehr

BACKGROUND: Overweight older adults are often counseled to lose weight, even though there is little evidence of excess mortality in that age group. Overweight and underweight may be more associated with health status than with mortality, but few clinical trials of any kind have been based on maximizing years of healthy life (YHL), as opposed to years of life (YOL). OBJECTIVE: This paper examines the relationship of body mass index (BMI) to both YHL and YOL. Results were used to determine whether clinical trials of weight-modification based on improving YHL would be more powerful than studies based on survival. DESIGN: …

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