Biostatistics Commons^™

Automated Diagnoses Of Attention Deficit Hyperactive Disorder Using Magnetic Resonance Imaging, Ani Eloyan, John Muschelli, Mary Beth Nebel, Han Liu, Fang Han, Tuo Zhao, Anita Barber, Suresh Joel, James J. Pekar, Stewart Mostofsky, Brian Caffo

Johns Hopkins University, Dept. of Biostatistics Working Papers

Successful automated diagnoses of attention de.cit hyperactive disorder (ADHD) using imaging and functional biomarkers would have fundamental consequences on the public health impact of the disease. In this work, we show results on the predictability of ADHD using imaging biomarkers and discuss the scienti.c and diagnostic impacts of the research. We created a prediction model using the land­mark ADHD 200 data set focusing on resting state functional connectivity (rs-fc) and structural brain imaging. We predicted ADHD status and subtype, obtained by behavioral examination, using imaging data, intelligence quotients and other co­variates. The novel contributions of this manuscript include a thorough …

Perbandingan Tingkat Kepuasan Kerja Perawat Dan Kepuasan Pasien, Jamilla Upik Noras, Ratu Ayu Dewi Sartika

Kesmas

Perawat adalah ujung tombak pemberi pelayanan langsung pada pasien selama 24 jam. Tujuan penelitian adalah untuk membandingkan tingkat kepuasan kerja perawat dengan kepuasan pasien terhadap pelayanan keperawatan kelas 3 di Rumah Sakit Umum Pusat (RSUP) X Jakarta. Penelitian ini bersifat deskriptif dengan desain studi cross sectional, pendekatan kuantitatif dan kualitatif. Populasi adalah seluruh perawat yang bertugas sebagai pelaksana keperawatan kelas 3 sebanyak 40 orang ser- ta pasien yang dirawat di ruang rawat inap kelas 3 sebanyak 120 orang. Pengambilan sampel dilakukan secara purposive sampling sesuai dengan kriteria inklusi dan ekslusi. Hasil pengukuran kuantitatif menunjukkan bah- wa tingkat kepuasan kerja perawat …

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, 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?, 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, 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., 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, 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, 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, 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, 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?, 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, 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, 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, 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, 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, Eric J. Tchetgen Tchetgen, James M. Robins

Harvard University Biostatistics Working Paper Series

No abstract provided.

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, 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, 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.