Demographics And Survival Of Aids Cases With Cancer, Washington, Dc, 1996-2006,
2012
George Washington University
Demographics And Survival Of Aids Cases With Cancer, Washington, Dc, 1996-2006, Heather A. Young, Eric Engels, Anne-Marie Sufian-Kargbo, Alicia Vargas, Kathleen Rogers, Tiffany West, Amanda D. Castel
Epidemiology Faculty Publications
Background
Washington, DC (DC) has one of the highest HIV/AIDS rates in the U.S and cancer is the second leading cause of death among DC residents. This study sought to examine the demographic characteristics and survival of persons with AIDS defining cancers (ADCs) compared to those with non-AIDS defining cancers (NADCs) between the early HAART era (1996-2001) and the late HAART era (2002-2006) in DC.
Methods
Cases reported from 1996-2006 to the DC Cancer Registry and the AIDS Surveillance Registry were linked using a probabilistic matching algorithm. Cases were included if the cancer occurred from 4 months to 60 months …
High And Persistent Hiv Seroincidence In Men Who Have Sex With Men Across 47 U.S. Cities,
2012
Centers for Disease Control and Prevention, Atlanta, GA
High And Persistent Hiv Seroincidence In Men Who Have Sex With Men Across 47 U.S. Cities, Marta-Louise Ackers, Alan E. Greenberg, Carol Y. Lin, Bradford N. Bartholow, Adrian Hirsch Goodman, Michael Longhi, Marc Gurwith
Epidemiology Faculty Publications
Objective
To provide HIV seroincidence data among men who have sex with men (MSM) in the United States and to identify predictive factors for seroconversion.
Methods
From 1998–2002, 4684 high-risk MSM, age 18–60 years, participated in a randomized, placebo-controlled HIV vaccine efficacy trial at 56 U.S. clinical trial sites. Demographics, behavioral data, and HIV status were assessed at baseline and 6 month intervals. Since no overall vaccine efficacy was detected, data were combined from both trial arms to calculate HIV incidence based on person-years (py) of follow-up. Predictors of seroconversion, adjusted hazards ratio (aHR), were evaluated using a Cox proportional …
Genetic Association Studies Of Copy-Number Variation: Should Assignment Of Copy Number States Precede Testing?,
2012
University of Kentucky
Genetic Association Studies Of Copy-Number Variation: Should Assignment Of Copy Number States Precede Testing?, Patrick Breheny, Prabhakar Chalise, Anthony Batzler, Liewei Wang, Brooke L. Fridley
Biostatistics Faculty Publications
Recently, structural variation in the genome has been implicated in many complex diseases. Using genomewide single nucleotide polymorphism (SNP) arrays, researchers are able to investigate the impact not only of SNP variation, but also of copy-number variants (CNVs) on the phenotype. The most common analytic approach involves estimating, at the level of the individual genome, the underlying number of copies present at each location. Once this is completed, tests are performed to determine the association between copy number state and phenotype. An alternative approach is to carry out association testing first, between phenotype and raw intensities from the SNP array …
Testing For Improvement In Prediction Model Performance,
2012
Fred Hutchinson Cancer Research Center
Testing For Improvement In Prediction Model Performance, Margaret S. Pepe Phd, Kathleen F. Kerr, Gary M. Longton, Zheyu Wang
UW Biostatistics Working Paper Series
New methodology has been proposed in recent years for evaluating the improvement in prediction performance gained by adding a new predictor, Y, to a risk model containing a set of baseline predictors, X, for a binary outcome D. We prove theoretically that null hypotheses concerning no improvement in performance are equivalent to the simple null hypothesis that the coefficient for Y is zero in the risk model, P(D = 1|X, Y ). Therefore, testing for improvement in prediction performance is redundant if Y has already been shown to be a risk factor. We investigate properties of tests through simulation studies, …
Progestogens To Prevent Preterm Birth In Twin Pregnancies: An Individual Participant Data Meta-Analysis Of Randomized Trials.,
2012
University Medical Centre Utrecht, Utrecht, Netherlands
Progestogens To Prevent Preterm Birth In Twin Pregnancies: An Individual Participant Data Meta-Analysis Of Randomized Trials., Ewoud Schuit, Sarah Stock, Rolf H.H. Groenwold, Kimberly Maurel, C. Andrew Combs, Thomas Garite, Catherine Y. Spong, Elizabeth A. Thom, Dwight J. Rouse, Steve N. Caritis, George Saade, Julia M. Zachary, Jane E. Norman, Line Rode, Katharina Klein, Ann Tabor, Elcin Cetingoz, John C. Morrison, Everett F. Magann, Christian M. Briery, Vicente Serra, Alfredo Perales, Juan Meseguer, Anwar Nassar, Arianne C. Lim, Karel G.M. Moons, Anneke Kwee, Ben W.J. Mol
Epidemiology Faculty Publications
Background
Preterm birth is the principal factor contributing to adverse outcomes in multiple pregnancies. Randomized controlled trials of progestogens to prevent preterm birth in twin pregnancies have shown no clear benefits. However, individual studies have not had sufficient power to evaluate potential benefits in women at particular high risk of early delivery (for example, women with a previous preterm birth or short cervix) or to determine adverse effects for rare outcomes such as intrauterine death.
Methods/design
We propose an individual participant data meta-analysis of high quality randomized, double-blind, placebo-controlled trials of progestogen treatment in women with a twin pregnancy. The …
Hierarchical Rank Aggregation With Applications To Nanotoxicology,
2012
UCLA, Biostatistics
Hierarchical Rank Aggregation With Applications To Nanotoxicology, Trina Patel, Donatello Telesca, Robert Rallo, Saji George, Xia Tian, Nel Andre
COBRA Preprint Series
The development of high throughput screening (HTS) assays in the field of nanotoxicology provide new opportunities for the hazard assessment and ranking of engineered nanomaterials (ENM). It is often necessary to rank lists of materials based on multiple risk assessment parameters, often aggregated across several measures of toxicity and possibly spanning an array of experimental platforms. Bayesian models coupled with the optimization of loss functions have been shown to provide an effective framework for conducting inference on ranks. In this article we present various loss function based ranking approaches for comparing ENM within experiments and toxicity parameters. Additionally, we propose …
Robustness Of Measures Of Interaction To Unmeasured Confounding,
2012
Harvard University
Robustness Of Measures Of Interaction To Unmeasured Confounding, Eric J. Tchetgen Tchetgen, Tyler J. Vanderweele
Harvard University Biostatistics Working Paper Series
No abstract provided.
Bootstrap-Based Inference On The Difference In The Means Of Two Correlated Functional Processes,
2012
Bloomberg School of Public Health, Department of Biostatistics, Johns Hopkins
Bootstrap-Based Inference On The Difference In The Means Of Two Correlated Functional Processes, Ciprian M. Crainiceanu, Ana-Maria Staicu, Shubankar Ray, Naresh Punjabi
Johns Hopkins University, Dept. of Biostatistics Working Papers
Nonparametric inference methods on the mean difference between two correlated Functional processes are proposed. We compare methods that: 1) incorporate different levels of smoothing of the mean and covariance; 2) preserve the sampling design; and 3) use parametric and nonparametric estimation of the mean functions. We apply our method to estimating the mean difference between average normalized δ-power of sleep electroencephalograms for 51 subjects with severe sleep apnea and 51 matched controls in the first 4 hours after sleep onset. Data are obtained from the Sleep Heart Health Study (SHHS), the largest community cohort study of sleep. While methods are …
Robustness Of Measures Of Interaction To Unmeasured Confounding,
2012
Harvard University
Robustness Of Measures Of Interaction To Unmeasured Confounding, Eric J. Tchetgen Tchetgen, Tyler J. Vanderweele
COBRA Preprint Series
In this paper, we study the impact of unmeasured confounding on inference about a two-way interaction in a mean regression model with identity, log or logit link function. Necessary and sufficient conditions are established for a two-way interaction to be nonparametrically identified from the observed data, despite unmeasured confounding for the factors defining the interaction. A lung cancer data application illustrates the results.
Does Secondary Inflammatory Breast Cancer Represent Post-Surgical Metastatic Disease?,
2012
George Washington University
Does Secondary Inflammatory Breast Cancer Represent Post-Surgical Metastatic Disease?, Salman Hashmi, Ladan Zolfaghari, Paul H. Levine
Epidemiology Faculty Publications
The phenomenon of accelerated tumor growth following surgery has been observed repeatedly and merits further study. Inflammatory breast carcinoma (IBC) is widely recognized as an extremely aggressive malignancy characterized by micrometastasis at the time of diagnosis, with one interesting subgroup defined as secondary IBC where pathologically identifiable IBC appears after surgical treatment of a primary non-inflammatory breast cancer. One possible mechanism can be related to the stimulation of dormant micrometastasis through local angiogenesis occurring as part of posttraumatic healing. In this report, we review cases of secondary IBC and others where localized trauma was followed by the appearance of IBC …
On A Logistic Mixed Model Formulation Of A Quadratic Exponential Model For Correlated Binary Outcomes,
2012
Harvard University
On A Logistic Mixed Model Formulation Of A Quadratic Exponential Model For Correlated Binary Outcomes, Eric J. Tchetgen Tchetgen
Harvard University Biostatistics Working Paper Series
No abstract provided.
On A Closed-Form Doubly Robust Estimator Of The Adjusted Odds Ratio For A Binary Exposure,
2012
Harvard University
On A Closed-Form Doubly Robust Estimator Of The Adjusted Odds Ratio For A Binary Exposure, Eric J. Tchetgen Tchetgen
Harvard University Biostatistics Working Paper Series
No abstract provided.
Formulae For Causal Mediation Analysis In An Odds Ratio Context Without A Normality Assumption For The Continuous Mediator,
2012
Harvard School of Public Health
Formulae For Causal Mediation Analysis In An Odds Ratio Context Without A Normality Assumption For The Continuous Mediator, Eric J. Tchetgen Tchetgen
Harvard University Biostatistics Working Paper Series
No abstract provided.
A Cautionary Note On Specification Of The Correlation Structure In Inverse-Probability-Weighted Estimation For Repeated Measures,
2012
Harvard University
A Cautionary Note On Specification Of The Correlation Structure In Inverse-Probability-Weighted Estimation For Repeated Measures, Eric J. Tchetgen Tchetgen, M. Maria Glymour, Jennifer Weuve, James Robins
Harvard University Biostatistics Working Paper Series
No abstract provided.
On Parametrization, Robustness And Sensitivity Analysis In A Marginal Structural Cox Proportional Hazards Model For Point Exposure,
2012
Harvard University
On Parametrization, Robustness And Sensitivity Analysis In A Marginal Structural Cox Proportional Hazards Model For Point Exposure, Eric J. Tchetgen Tchetgen, James M. Robins
Harvard University Biostatistics Working Paper Series
No abstract provided.
Multiple-Robust Estimation Of An Odds Ratio Interaction,
2012
Harvard University
Multiple-Robust Estimation Of An Odds Ratio Interaction, Eric J. Tchetgen Tchetgen
Harvard University Biostatistics Working Paper Series
No abstract provided.
Inverse Odds Ratio-Weighted Estimation For Causal Mediation Analysis,
2012
Harvard University
Inverse Odds Ratio-Weighted Estimation For Causal Mediation Analysis, Eric J. Tchetgen Tchetgen
Harvard University Biostatistics Working Paper Series
No abstract provided.
Effect Of Nutrition Changes On Foods Selected By Students In A Middle School-Based Diabetes Prevention Intervention Program: The Healthy Experience,
2012
University of Nevada Las Vegas
Effect Of Nutrition Changes On Foods Selected By Students In A Middle School-Based Diabetes Prevention Intervention Program: The Healthy Experience, Connie Mobley, Diane D. Stadler, Myrlene A. Staten, Laure El Ghormli, Bonnie Gillis, Jill Hartstein, Anna Maria Siega-Riz, Amy Virus, Healthy Study Group
GW Biostatistics Center
No abstract provided.
Repeat Prenatal Corticosteroid Prior To Preterm Birth: A Systematic Review And Individual Participant Data Meta-Analysis For The Precise Study Group (Prenatal Repeat Corticosteroid International Ipd Study Group: Assessing The Effects Using The Best Level Of Evidence) - Study Protocol,
2012
Women and Children's Hospital, Adelaide, Australia
Repeat Prenatal Corticosteroid Prior To Preterm Birth: A Systematic Review And Individual Participant Data Meta-Analysis For The Precise Study Group (Prenatal Repeat Corticosteroid International Ipd Study Group: Assessing The Effects Using The Best Level Of Evidence) - Study Protocol, Caroline A. Crowther, Fariba Aghajafari, Lisa M. Askie, Elizabeth V. Asztalos, Peter Brocklehurst, Elizabeth A. Thom, +22 Additional Authors
GW Biostatistics Center
Background
The aim of this individual participant data (IPD) meta-analysis is to assess whether the effects of repeat prenatal corticosteroid treatment given to women at risk of preterm birth to benefit their babies are modified in a clinically meaningful way by factors related to the women or the trial protocol.
Methods/Design
The Prenatal Repeat Corticosteroid International IPD Study Group: assessing the effects using the best level of Evidence (PRECISE) Group will conduct an IPD meta-analysis. The PRECISE International Collaborative Group was formed in 2010 and data collection commenced in 2011. Eleven trials with up to 5,000 women and 6,000 infants …
Alternate Estrogen Receptors Promote Invasion Of Inflammatory Breast Cancer Cells Via Non-Genomic Signaling,
2012
George Washington University
Alternate Estrogen Receptors Promote Invasion Of Inflammatory Breast Cancer Cells Via Non-Genomic Signaling, Kazufumi Ohshiro, Arnold M. Schwartz, Paul H. Levine, Rakesh Kumar
Epidemiology Faculty Publications
Although Inflammatory Breast Cancer (IBC) is a rare and an aggressive type of locally advanced breast cancer with a generally worst prognosis, little work has been done in identifying the status of non-genomic signaling in the invasiveness of IBC. The present study was performed to explore the status of non-genomic signaling as affected by various estrogenic and anti-estrogenic agents in IBC cell lines SUM149 and SUM190. We have identified the presence of estrogen receptor α (ERα) variant, ERα36 in SUM149 and SUM190 cells. This variant as well as ERβ was present in a substantial concentration in IBC cells. The treatment …
