Biostatistics Commons^™

Progression Of Electrocardiographic Abnormalities In Type 1 Diabetes During 16 Years Of Follow‐Up: The Epidemiology Of Diabetes Interventions And Complications (Edic) Study, Elsayed Soliman, Jye-Yu Backlund, Ionut Bebu, Yabing Li, Zhu-Ming Zhang, Patricia A. Cleary, John M. Lachin

GW Biostatistics Center

Background The electrocardiogram (ECG) is an objective tool for cardiovascular disease (CVD) risk assessment.

Methods and Results We evaluated distribution of ECG abnormalities and risk factors for developing new abnormalities in 1314 patients with type 1 diabetes (T1D) from the Epidemiology of Diabetes Interventions and Complications (EDIC) study. Annual ECGs were centrally read. ECG abnormalities were classified as major and minor according to the Minnesota ECG Classification. At EDIC year 1 (baseline), 356 (27.1%) of the participants had at least 1 ECG abnormality (major or minor) whereas 26 (2%) had at least one major abnormality. During 16 years of follow‐up, …

Knowledge And Behavior Change Of People Living With Hiv Through Nutrition Education And Counseling, Fitri Hudayani, Ratu Ayu Dewi Sartika

Kesmas

HIV, AIDS, dan gizi saling berhubungan. Pada Unit Pelayanan Terpadu HIV Rumah Sakit Umum Pusat Nasional Dr. Cipto Mangunkusumo, layanan edukasi dan konseling gizi disediakan secara kolaboratif untuk orang yang hidup dengan HIV. Penelitian ini bertujuan untuk mengetahui pengaruh pendidikan dan konseling gizi terhadap pengetahuan dan perilaku orang yang hidup dengan HIV. Penelitian ini dilakukan dengan desain kuasi eksperimental menggunakan kelompok perlakuan dan kontrol. Kelompok perlakuan terdiri dari 25 sampel dan 29 sampel untuk kelompok kontrol, dilakukan sebelum dan setelah perlakuan. Sampel berusia dewasa antara 18 – 50 tahun dipilih dengan menerapkan kriteria inklusi dan eksklusi. Sampel uji-t berpasangan digunakan …

Influence Of Household Environment And Maternal Behaviors To Upper Respiratory Infection Among Toddlers, Reny Fahdiyani, Ardini S. Raksanagara, Hadyana Sukandar

Kesmas

Infeksi saluran pernapasan akut atas (ISPA atas) di negara berkembang menyebabkan morbiditas tinggi pada anak bawah usia lima tahun (balita). Kementerian Kesehatan Republik Indonesia melaporkan bahwa ISPAnonpneumonia meningkat 2,6% dari tahun 2007 ke 2011. Faktor risiko yang dapat berkontribusi termasuk lingkungan dan perilaku. Penelitian ini bertujuan untuk menyelidiki faktor perilaku dan lingkungan dengan ISPA atas pada balita. Studi kasus kontrol ini dilakukan dari Februari-April 2015 pada balita di Tamansari yang merupakan daerah kumuh di Kota Bandung. Kasus adalah 55 ibu dengan balita menderita ISPA atas yang datang ke puskesmas, sedangkan kontrol dua kali lebih besar dari kasus dipilih dari lingkungan …

Predisposing Factors With Complementary Feeding Practices Among 9-11 Month-Old Infants In Jakarta Urban Slum Area, Septriana Septriana, Gita Ardelia Suhartono

Kesmas

Penyebab utama kekurangan gizi selain dari penyakit infeksi adalah pola asuh yang tidak sesuai dan pemberian makan yang optimal menjadi salah satu cara untuk mengatasi konsekuensi jangka panjang dari kekurangan zat gizi. Penelitian ini bertujuan untuk mengetahui hubungan antara faktor pendukung praktik pemberian makanan pendamping air susu ibu (MPASI) pada bayi usia 9 - 11 bulan di daerah kumuh perkotaan Jakarta. Penelitian potong lintang ini melibatkan 50 orang pengasuh bayi usia 9 – 11 bulan. Data dikumpulkan melalui wawancara menggunakan kuesioner. Tidak terdapat hubungan yang bermakna antara usia pengasuh dengan praktik pemberian makan (nilai p = 0,645). Demikian juga dengan …

Residential Density, Parents’ Sexual Activity And Teenage Sexual Behavior In Yogyakarta, Luluk Rosida, Evi Martha, Besral Besral

Kesmas

Pada daerah kumuh dan padat, orangtua sering terpaksa harus berbagi ruang tidur dengan anak-anaknya sehingga anak-anaknya sudah terpapar dengan aktivitas seksual sejak dini. Penelitian ini bertujuan mengetahui kepadatan hunian, aktivitas seksual orangtua, dan efeknya terhadap perilaku seksual remaja di Yogyakarta. Penelitian ini menggunakan desain potong lintang dengan mewawancarai 268 keluarga yang memiliki anak remaja yang dipilih secara acak di daerah kumuh perkotaan dan daerah pedesaan pada bulan Maret – Mei 2015. Analisis data dilakukan menggunakan uji kai kuadrat dan regresi-cox multivariat. Hasil penelitian ini menunjukkan bahwa orangtua yang tinggal di hunian padat memiliki risiko dua kali lebih besar untuk melakukan …

Effects Of Mothers’ Attitude As Breeders And Distance Of Stockyard Toward Diarrhea Incidence Among Toddlers, Yarmaliza Yarmaliza, Sugito Sugito, Teuku Reza Ferasyi, Nurliana Nurliana, Razali Razali

Kesmas

Diare merupakan penyakit dengan perubahan bentuk dan konsentrasi tinja yang melembek sampai mencair, dan bertambahnya frekuensi buang air besar lebih dari biasanya (tiga kali atau lebih dalam sehari). Di Provinsi Aceh, terdapat kasus diare sebanyak 48/1.000 kelahiran hidup pada 2013. Di Kabupaten Aceh Barat, pada tahun 2014 terdapat 1.071 kasus, sedangkan di Kecamatan Meureubo terdapat sebanyak 70 kasus pada anak bawah lima tahun (balita). Penelitian ini bertujuan untuk mengetahui hubungan sikap ibu sebagai peternak dan jarak kandang ternak terhadap kejadian diare pada balita di wilayah kerja Puskesmas Kecamatan Meureubo. Penelitian ini dilakukan secara potong lintang pada bulan Juli – September …

Cadmium Contamination In Farmland Soil And Water Near Zinc Mining Site, Kanitta Jiraungkoorskul, Sara Arphorn, Mathuros Tipayamongholgul, Wattasit Siriwong

Kesmas

Penelitian ini merupakan penelitian potong lintang yang dilakukan di Kecamatan Phatadpaeng, Kota Mae Sod, Provinsi Tak, Thailand. Penelitian ini bertujuan untuk mengetahui konsentrasi kadmium pada air dan tanah pertanian serta pada pemukiman petani dan rumah tangga. Konsentrasi kadmium pada 48 sampel tanah dan air pemukiman petani, 12 sampel rumah tangga, enam sampel tanah pertanian, dan delapan sampel air pertanian ditelusuri menggunakan Graphite Furnace Atomic Absorption Spectrophotometer. Uji Mann-Whitney U digunakan untuk analisis perbedaan konsentrasi kadmium antara tanah pertanian dan tanah pemukiman, air pertanian dan air pemukiman. Hasil penelitian menunjukkan tidak terdapat perbedaan secara statistik pada seluruh matriks, namun air dan …

Study On Clinical, Histopathological Features And Evaluation Results Of Skin Cancer Treatment In Can Tho Oncology Hospital, Nguyen Van Qui, Phan Nguyen Ngoc

Kesmas

Kanker kulit, diagnosis kanker paling umum, cenderung mengalami peningkatan. Kondisi ini secara khusus merupakan isu penting di negara-negara maju. Penelitian ini bertujuan untuk mendeskripsikan fitur klinis, fitur hispatologis, komplikasi dan hasil pengobatan bedah awal kanker kulit di Rumah Sakit Onkologi Can Tho dari tahun 2014 sampai 2015. Penelitian deskriptif prospektif ini melibatkan seluruh pasien dengan kanker kulit nonmelanoma yang diuji dan diobati di Rumah Sakit Onkologi Can Tho dari Juli 2014 sampai Maret 2015. Terdapat 78 kasus terpilih. Kanker kulit ditemukan lebih umum pada pasien yang lebih tua. Prevalensi karsinoma sel basal ditemukan lebih tinggi dibandingkan karsinoma sel skuamosa dengan …

Communication Of Parents, Sexual Content Intake And Teenage Sexual Behavior At Senior High School In Banjarmasin City, Rusmilawaty Rusmilawaty, Yuniarti Yuniarti, Tri Tunggal

Kesmas

Perilaku seks bebas di kalangan remaja Kota Banjarmasin belakangan ini semakin mengkhawatirkan para orangtua. Kurangnya pendidikan seksologi berdampak para remaja cenderung melakukan hubungan seksual pranikah yang akan berakibat pada kehamilan yang tidak diinginkan dan pernikahan dini. Komunikasi orangtua-anak dan paparan media baik media cetak maupun elektronik merupakan cara untuk mengurangi perilaku seksual berisiko. Tujuan penelitian ini untuk mengetahui hubungan komunikasi orangtua dan asupan muatan seksual dengan perilaku seksual remaja sekolah menengah atas (SMA) di Kota Banjarmasin. Untuk mencapai tujuan tersebut, penelitian survei analitik dengan pendekatan potong lintang dilakukan pada bulan Juli – Oktober 2015 di dua sekolah negeri dan satu …

Crtgeedr: An R Package For Doubly Robust Generalized Estimating Equations Estimations In Cluster Randomized Trials With Missing Data, Melanie Prague, Rui Wang, Victor De Gruttola

Harvard University Biostatistics Working Paper Series

No abstract provided.

Statistical Interpretation Including The Appropriate Statistical Tests, Olga A. Vsevolozhskaya

Biostatistics Presentations

Outline:

1. Evaluation of treatment’s therapeutic potential after experimental stroke.
2. Post-stroke behavioral testing and functional recovery.

Alzheimer's Biomarkers Are Correlated With Brain Connectivity In Older Adults Differentially During Resting And Task States, Yang Jiang, Haiqing Huang, Erin Abner, Lucas S. Broster, Gregory A. Jicha, Frederick A. Schmitt, Richard Kryscio, Anders H. Andersen, David Powell, Linda J. Van Eldik, Brian T. Gold, Peter T. Nelson, Charles D. Smith, Mingzhou Ding

Behavioral Science Faculty Publications

β-amyloid (Aβ) plaques and tau-related neurodegeneration are pathologic hallmarks of Alzheimer’s disease (AD). The utility of AD biomarkers, including those measured in cerebrospinal fluid (CSF), in predicting future AD risk and cognitive decline is still being refined. Here, we explored potential relationships between functional connectivity (FC) patterns within the default-mode network (DMN), age, CSF biomarkers (Aβ₄₂ and pTau₁₈₁), and cognitive status in older adults. Multiple measures of FC were explored, including a novel time series-based measure [total interdependence (TI)]. In our sample of 27 cognitively normal older adults, no significant associations were found between levels of Aβ …

Hpcnmf: A High-Performance Toolbox For Non-Negative Matrix Factorization, Karthik Devarajan, Guoli Wang

COBRA Preprint Series

Non-negative matrix factorization (NMF) is a widely used machine learning algorithm for dimension reduction of large-scale data. It has found successful applications in a variety of fields such as computational biology, neuroscience, natural language processing, information retrieval, image processing and speech recognition. In bioinformatics, for example, it has been used to extract patterns and profiles from genomic and text-mining data as well as in protein sequence and structure analysis. While the scientific performance of NMF is very promising in dealing with high dimensional data sets and complex data structures, its computational cost is high and sometimes could be critical for …

A Test Of Symmetry Based On The Kernel Kullback-Leibler Information With Application To Base Deficit Data, Hani M. Samawi, Robert L. Vogel

Biostatistics: Faculty Publications

The assumption of the symmetry of the underlying distribution is important to many statistical inference and modeling procedures. This paper provides a test of symmetry using kernel density estimation and the Kullback-Leibler information. Based on simulation studies, the new test procedure outperforms other tests of symmetry found in the literature, including the Runs Test of Symmetry. We illustrate our new procedure using real data.

Accounting For Interactions And Complex Inter-Subject Dependency In Estimating Treatment Effect In Cluster Randomized Trials With Missing Outcomes, Melanie Prague, Rui Wang, Alisa Stephens, Eric Tchetgen Tchetgen, Victor Degruttola

Harvard University Biostatistics Working Paper Series

No abstract provided.

Models For Hsv Shedding Must Account For Two Levels Of Overdispersion, Amalia Magaret

UW Biostatistics Working Paper Series

We have frequently implemented crossover studies to evaluate new therapeutic interventions for genital herpes simplex virus infection. The outcome measured to assess the efficacy of interventions on herpes disease severity is the viral shedding rate, defined as the frequency of detection of HSV on the genital skin and mucosa. We performed a simulation study to ascertain whether our standard model, which we have used previously, was appropriately considering all the necessary features of the shedding data to provide correct inference. We simulated shedding data under our standard, validated assumptions and assessed the ability of 5 different models to reproduce the …

An Efficient Basket Trial Design, Kristen Cunanan, Alexia Iasonos, Ronglai Shen, Colin B. Begg, Mithat Gonen

Memorial Sloan-Kettering Cancer Center, Dept. of Epidemiology & Biostatistics Working Paper Series

The landscape for early phase cancer clinical trials is changing dramatically due to the advent of targeted therapy. Increasingly, new drugs are designed to work against a target such as the presence of a specific tumor mutation. Since typically only a small proportion of cancer patients will possess the mutational target, but the mutation is present in many different cancers, a new class of basket trials is emerging, whereby the drug is tested simultaneously in different baskets, i.e., sub-groups of different tumor types. Investigators not only desire to test whether the drug works, but also to determine which types of …

Variable Selection For Case-Cohort Studies With Failure Time Outcome, Andy Ni, Jianwen Cai, Donglin Zeng

Memorial Sloan-Kettering Cancer Center, Dept. of Epidemiology & Biostatistics Working Paper Series

Case-cohort designs are widely used in large cohort studies to reduce the cost associated with covariate measurement. In many such studies the number of covariates is very large, so an efficient variable selection method is necessary. In this paper, we study the properties of variable selection using the smoothly clipped absolute deviation penalty in a case-cohort design with a diverging number of parameters. We establish the consistency and asymptotic normality of the maximum penalized pseudo-partial likelihood estimator, and show that the proposed variable selection procedure is consistent and has an asymptotic oracle property. Simulation studies compare the finite sample performance …

Leveraging Contact Network Structure In The Design Of Cluster Randomized Trials, Guy Harling, Rui Wang, Jukka-Pekka Onnela, Victor Degruttola

Harvard University Biostatistics Working Paper Series

Background: In settings like the Ebola epidemic, where proof-of-principle trials have succeeded but questions remain about the effectiveness of different possible modes of implementation, it may be useful to develop trials that not only generate information about intervention effects but also themselves provide public health benefit. Cluster randomized trials are of particular value for infectious disease prevention research by virtue of their ability to capture both direct and indirect effects of intervention; the latter of which depends heavily on the nature of contact networks within and across clusters. By leveraging information about these networks – in particular the degree …

Using Validation Data To Adjust The Inverse Probability Weighting Estimator For Misclassified Treatment, Danielle Braun, Corwin Zigler, Francesca Dominici, Malka Gorfine

Harvard University Biostatistics Working Paper Series

The inverse probability weighting (IPW) estimator is widely used to estimate the treatment effect in observational studies in which patient characteristics might not be balanced by treatment group. The estimator assumes that treatment assignment, is error-free, but in reality treatment assignment can be measured with error. This arises in the context of comparative effectiveness research, using administrative data sources in which accurate procedural or billing codes are not always available. We show the bias introduced to the estimator when using error-prone treatment assignment, and propose an adjusted estimator using a validation study to eliminate this bias. In simulations, we explore …

Estimation And Inference For The Mediation Proportion, Daniel Nevo, Xiaomei Liao, Donna Spiegelman

Harvard University Biostatistics Working Paper Series

In epidemiology, public health and social science, mediation analysis is often undertaken to investigate the extent to which the effect of a risk factor on an outcome of interest is mediated by other covariates. A pivotal quantity of interest in such an analysis is the mediation proportion. A common method for estimating it, termed the "difference method'', compares estimates from models with and without the hypothesized mediator. However, rigorous methodology for estimation and statistical inference for this quantity has not previously been available. We formulated the problem for the Cox model and generalized linear models, and utilize a data duplication …

A Cautionary Note On The Effect Of Treatment Misclassification On The Average Treatment Effect, Danielle Braun, Corwin Zigler, Malka Gorfine, Francesca Dominici

Harvard University Biostatistics Working Paper Series

Comparative effectiveness research often relies on large administrative data, such as claims data. Methods to estimate treatment effects assume that treatment assignment is error-free, but in reality the inaccuracy of procedural or billing codes frequently misclassifies patients into treatment groups. Propensity score methods are widely used to analyze observational studies in which patient characteristics might not be balanced by treatment group. We evaluate the impact of treatment misclassification on 1) propensity score estimation; 2) treatment effect estimation conditional on propensity score estimation and implementation. We focus on three common propensity score implementations: subclassification, matching, and inverse probability of treatment weighting …

The Myth Of Making Inferences For An Overall Treatment Efficacy With Data From Multiple Comparative Studies Via Meta-Analysis, Takahiro Hasegawa, Brian Claggett, Lu Tian, Scott D. Solomon, Marc A. Pfeffer, Lee-Jen Wei

Harvard University Biostatistics Working Paper Series

Meta analysis techniques, if applied appropriately, can provide a summary of the totality of evidence regarding an overall difference between a new treatment and a control group using data from multiple comparative clinical studies. The standard meta analysis procedures, however, may not give a meaningful between-group difference summary measure or identify a meaningful patient population of interest, especially when the fixed effect model assumption is not met. Moreover, a single between-group comparison measure without a reference value obtained from patients in the control arm would likely not be informative enough for clinical decision making. In this paper, we propose a …

Moving Beyond The Conventional Stratified Analysis To Estimate An Overall Treatment Efficacy With The Data From A Comparative Randomized Clinical Study, Lu Tian, Fei Jiang, Takahiro Hasegawa, Hajime Uno, Marc Alan Pfeffer, L.J. Wei

Harvard University Biostatistics Working Paper Series

No abstract provided.

Detectable Viral Load In Late Pregnancy Among Women In The Rwanda Option B+ Pmtct Program: Enrollment Results From The Kabeho Study., Michelle M Gill, Heather J Hoffman, Emily A Bobrow, Placidie Mugwaneza, Dieudonne Ndatimana, Gilles F Ndayisaba, Cyprien Baribwira, Laura Guay, Anita Asiimwe

Epidemiology Faculty Publications

There are limited viral load (VL) data available from programs implementing "Option B+," lifelong antiretroviral treatment (ART) to all HIV-positive pregnant and postpartum women, in resource-limited settings. Extent of viral suppression from a prevention of mother-to-child transmission of HIV program in Rwanda was assessed among women enrolled in the Kigali Antiretroviral and Breastfeeding Assessment for the Elimination of HIV (Kabeho) Study. ARV drug resistance testing was conducted on women with VL>2000 copies/ml. In April 2013-January 2014, 608 pregnant or early postpartum HIV-positive women were enrolled in 14 facilities. Factors associated with detectable enrollment VL (>20 copies/ml) were examined …

Male Pattern Baldness In Relation To Prostate Cancer–Specific Mortality: A Prospective Analysis In The Nhanes I Epidemiologic Follow-Up Study, Cindy Ke Zhou, Paul H Levine, Sean D. Cleary, Heather J. Hoffman, Barry I Graubard, Michael B. Cook

Epidemiology Faculty Publications

We used male pattern baldness as a proxy for long-term androgen exposure and investigated the association of dermatologist-assessed hair loss with prostate cancer–specific mortality in the first National Health and Nutrition Examination Survey Epidemiologic Follow-up Study. From the baseline survey (1971–1974), we included 4,316 men who were 25–74 years of age and had no prior cancer diagnosis. We estimated hazard ratios and used Cox proportional hazards regressions with age as the time metric and baseline hazard stratified by baseline age. A hybrid framework was used to account for stratification and clustering of the sample design, with adjustment for the variables …

Socioecological Factors Influencing Women's Hiv Risk In The United States: Qualitative Findings From The Women's Hiv Seroincidence Study (Hptn 064)., Paula M Frew, Kimberly Parker, Linda Vo, Danielle Haley, Ann O'Leary, Dazon Dixon Diallo, Carol E Golin, Irene Kuo, Lydia Soto-Torres, Jing Wang, Adaora A Adimora, Laura A Randall, Carlos Del Rio, Sally Hodder, Hiv Prevention Trials Network 064 (Htpn) Study Team.

Epidemiology Faculty Publications

BACKGROUND: We sought to understand the multilevel syndemic factors that are concurrently contributing to the HIV epidemic among women living in the US. We specifically examined community, network, dyadic, and individual factors to explain HIV vulnerability within a socioecological framework.

METHODS: We gathered qualitative data (120 interviews and 31 focus groups) from a subset of women ages 18-44 years (N = 2,099) enrolled in the HPTN 064 HIV seroincidence estimation study across 10 US communities. We analyzed data from 4 diverse locations: Atlanta, New York City (the Bronx), Raleigh, and Washington, DC. Data were thematically coded using grounded theory methodology. …

Improving Hiv Surveillance Data For Public Health Action In Washington, Dc: A Novel Multiorganizational Data-Sharing Method, Joanne Ocampo, J. C. Smart, Adam Allston, Reshma Bhattacharjee, Sahithi Boggavarapu, Amanda D. Castel, +13 More

GW Biostatistics Center

Background: The National HIV/AIDS Strategy calls for active surveillance programs for human immunodeficiency virus (HIV) to more accurately measure access to and retention in care across the HIV care continuum for persons living with HIV within their jurisdictions and to identify persons who may need public health services. However, traditional public health surveillance methods face substantial technological and privacy-related barriers to data sharing.

Objective: This study developed a novel data-sharing approach to improve the timeliness and quality of HIV surveillance data in three jurisdictions where persons may often travel across the borders of the District of Columbia, Maryland, and Virginia. …

Skin Collagen Fluorophore Lw-1 Versus Skin Fluorescence As Markers For The Long-Term Progression Of Subclinical Macrovascular Disease In Type 1 Diabetes., David R Sell, Wanjie Sun, Xiaoyu Gao, Christopher Strauch, John M. Lachin, Patricia A Cleary, Saul Genuth, Ddit/Edic Research Group, Vincent M Monnier

GW Biostatistics Center

BACKGROUND: Skin collagen Long Wavelength Fluorescence (LWF) is widely used as a surrogate marker for accumulation of advanced glycation end-products. Here we determined the relationship of LWF with glycemia, skin fluorescence, and the progression of complications during EDIC in 216 participants from the DCCT.

METHODS: LW-1 and collagen-linked fluorescence (CLF) were measured by either High Performance Liquid Chromatography (HPLC) with fluorescence detection (LW-1) or total fluorescence of collagenase digests (CLF) in insoluble skin collagen extracted from skin biopsies obtained at the end of the DCCT (1993). Skin intrinsic fluorescence (SIF) was noninvasively measured on volar forearm skin at EDIC year …

D-Dimer Levels Before Hiv Seroconversion Remain Elevated Even After Viral Suppression And Are Associated With An Increased Risk Of Non-Aids Events, Matthew S Freiberg, Ionut Bebu, Russell Tracy, Kaku So-Armah, Jason Okulicz, Anuradha Ganesan, Adam Armstrong, Thomas O'Bryan, David Rimland, Amy C Justice, Brian K Agan

GW Biostatistics Center

The mechanism underlying the excess risk of non-AIDS diseases among HIV infected people is unclear. HIV associated inflammation/hypercoagulability likely plays a role. While antiretroviral therapy (ART) may return this process to pre-HIV levels, this has not been directly demonstrated. We analyzed data/specimens on 249 HIV+ participants from the US Military HIV Natural History Study, a prospective, multicenter observational cohort of >5600 active duty military personnel and beneficiaries living with HIV. We used stored blood specimens to measure D-dimer and Interleukin-6 (IL-6) at three time points: pre-HIV seroconversion, ≥6 months post-HIV seroconversion but prior to ART initiation, and ≥6 months post-ART …