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Generalized Confidence Intervals And Fiducial Intervals For Some Epidemiological Measures., Ionut Bebu, G. Luta, T. Mathew, B. K. Agan

GW Biostatistics Center

For binary outcome data from epidemiological studies, this article investigates the interval estimation of several measures of interest in the absence or presence of categorical covariates. When covariates are present, the logistic regression model as well as the log-binomial model are investigated. The measures considered include the common odds ratio (OR) from several studies, the number needed to treat (NNT), and the prevalence ratio. For each parameter, confidence intervals are constructed using the concepts of generalized pivotal quantities and fiducial quantities. Numerical results show that the confidence intervals so obtained exhibit satisfactory performance in terms of maintaining the coverage probabilities …

Significance Of Epicardial And Intrathoracic Adipose Tissue Volume Among Type 1 Diabetes Patients In The Dcct/Edic: A Pilot Study., Sirous Darabian, Jye-Yu C Backlund, Patricia A Cleary, Nasim Sheidaee, Ionut Bebu, John M. Lachin, Matthew J Budoff, Dcct/Edic Research Group

GW Biostatistics Center

Introduction

Type 1 diabetes (T1DM) patients are at increased risk of coronary artery disease (CAD). This pilot study sought to evaluate the relationship between epicardial adipose tissue (EAT) and intra-thoracic adipose tissue (IAT) volumes and cardio-metabolic risk factors in T1DM.

Method

EAT/IAT volumes in 100 patients, underwent non-contrast cardiac computed tomography in the Diabetes Control and Complications Trial /Epidemiology of Diabetes Interventions and Complications (DCCT/EDIC) study were measured by a certified reader. Fat was defined as pixels’ density of -30 to -190 Hounsfield Unit. The associations were assessed using–Pearson partial correlation and linear regression models adjusted for gender and age …

Lymphoblastoid Cell Lines As A Tool To Study Inter-Individual Differences In The Response To Glucose., Michael A Grassi, Vidhya R Rao, Siquan Chen, Dingcai Cao, Xiaoyu Gao, Patricia A. Cleary, R Stephanie Huang, Andrew D Paterson, Rama Natarajan, Jalees Rehman, Timothy S Kern

GW Biostatistics Center

BACKGROUND: White blood cells have been shown in animal studies to play a central role in the pathogenesis of diabetic retinopathy. Lymphoblastoid cells are immortalized EBV-transformed primary B-cell leukocytes that have been extensively used as a model for conditions in which white blood cells play a primary role. The purpose of this study was to investigate whether lymphoblastoid cell lines, by retaining many of the key features of primary leukocytes, can be induced with glucose to demonstrate relevant biological responses to those found in diabetic retinopathy.

METHODS: Lymphoblastoid cell lines were obtained from twenty-three human subjects. Differences between high and …

Importance Of Hereditary And Selected Environmental Risk Factors In The Etiology Of Inflammatory Breast Cancer: A Case-Comparison Study., Roxana Moslehi, Elizabeth Freedman, Nur Zeinomar, Carmela Veneroso, Paul H. Levine

Epidemiology Faculty Publications

BACKGROUND: To assess the importance of heredity in the etiology of inflammatory breast cancer (IBC), we compared IBC patients to several carefully chosen comparison groups with respect to the prevalence of first-degree family history of breast cancer.

METHODS: IBC cases (n = 141) were compared to non-inflammatory breast cancer cases (n = 178) ascertained through George Washington University (GWU) with respect to the prevalence of first-degree family history of breast cancer and selected environmental/lifestyle risk factors for breast cancer. Similar comparisons were conducted with subjects from three case-control studies: breast cancer cases (n = 1145) and unaffected controls (n = …

Importance Of Hereditary And Selected Environmental Risk Factors In The Etiology Of Inflammatory Breast Cancer: A Case-Comparison Study., Roxana Moslehi, Elizabeth Freedman, Nur Zeinomar, Carmela Veneroso, Paul H. Levine

Epidemiology Faculty Publications

BACKGROUND: To assess the importance of heredity in the etiology of inflammatory breast cancer (IBC), we compared IBC patients to several carefully chosen comparison groups with respect to the prevalence of first-degree family history of breast cancer.

METHODS: IBC cases (n = 141) were compared to non-inflammatory breast cancer cases (n = 178) ascertained through George Washington University (GWU) with respect to the prevalence of first-degree family history of breast cancer and selected environmental/lifestyle risk factors for breast cancer. Similar comparisons were conducted with subjects from three case-control studies: breast cancer cases (n = 1145) and unaffected controls (n = …

Interruptions Of Antiretroviral Therapy In Children And Adolescents With Hiv Infection In Clinical Practice: A Retrospective Cohort Study In The Usa., Natella Rakhmanina, Kam S Lam, Jaclyn Hern, Heather A. Young, Alex Walters, Amanda D. Castel

Epidemiology Faculty Publications

INTRODUCTION: Changes in combination antiretroviral therapy (cART) throughout childhood challenge the continuity of paediatric HIV treatment. This study aimed to evaluate the prevalence of treatment interruption (TI), including lamivudine (3TC) monotherapy, and the relationship of TI to virologic and immunologic parameters in HIV-infected paediatric patients.

METHODS: Nested within a prospective observational study of a city-wide cohort of HIV-infected persons in the District of Columbia, this sub-study collected retrospective data on antiretroviral therapy, enrolment (endpoint) and historic (lifelong) CD4 counts and HIV RNA viral load (VL) of the paediatric cohort. TI was defined as interruption of cART ≥4 consecutive weeks. Data …

Arsenic In Drinking Water And Lung Cancer Mortality In The United States: An Analysis Based On Us Counties And 30 Years Of Observation (1950-1979)., Hamid Ferdosi, Elisabeth K Dissen, Nana Ama Afari-Dwamena, Ji Li, Rusan Chen, Manning Feinleib, Steven H Lamm

Epidemiology Faculty Publications

Background. To examine whether the US EPA (2010) lung cancer risk estimate derived from the high arsenic exposures (10-934 µg/L) in southwest Taiwan accurately predicts the US experience from low arsenic exposures (3-59 µg/L). Methods. Analyses have been limited to US counties solely dependent on underground sources for their drinking water supply with median arsenic levels of ≥3 µg/L. Results. Cancer risks (slopes) were found to be indistinguishable from zero for males and females. The addition of arsenic level did not significantly increase the explanatory power of the models. Stratified, or categorical, analysis yielded relative risks that hover about 1.00. …

Evaluating A Bystander Intervention Program On Reproductive Coercion: Using Quasi-Experimental Design Strategies To Address Methodologic Issues In Randomized Community Prevention Trials, Catherine P. Starnes

Theses and Dissertations--Epidemiology and Biostatistics

Community (or cluster) randomized trials are trials in which communities or groups of individuals (clusters) are randomized to receive the intervention of interest. Community randomized trials frequently more closely resemble a natural experiment than a randomized controlled trial (RCT) following intervention allocation. In particular, the effects of non-compliance can pose methodologic challenges in estimating the intervention effect which may require a quasiexperimental approach in order to minimize bias.

The motivating example to illustrate these issues is the Green Dot High School (GDHS) study. The GDHS study was a longitudinal, cluster-randomized controlled trial designed to assess the effectiveness of a bystander …

The Association Between Osteoporosis And Early Menopause Following Hysterectomy, Mia Meeyaong-Won Botkin

Walden Dissertations and Doctoral Studies

Osteoporosis is considered to be the most adverse public health disease associated with substantial mortality among postmenopausal women. Hysterectomy, surgically induced menopause, contributes to the early onset of menopause. However, there was no evidence of an association between early menopause following hysterectomy and osteoporosis among postmenopausal women. The purpose of this quantitative study was to examine the association between demographic and behavioral factors and the prevalence of osteoporosis among hysterectomized postmenopausal women. The integrated theory of health behavior change theoretical framework guided study. Cross-sectional secondary data from the 2009-2010 National Health and Nutrition Examination Survey were used. Multiple logistic regression …

Spatio-Temporal Analysis Of The Occupational Fatal Victimization Of Law Enforcement Officers In The Us, Xueyi Xing

Theses and Dissertations

The models with constant coefficients of the covariates across space and time are commonly used in spatio-temporal analyses. However, the associations between risk factors and the outcome could have locally differential temporal trends in many cases. In this study, a Bayesian latent cluster modeling strategy is employed to identify potential spatial clusters in which locally specific sets of temporally varying coefficients of covariates are allowed. A state-level panel data of police officers occupational fatal victimization for the years 1979-2010 is used. To accommodate overdisperson and excess zeros, a negative binomial model and zero-inflated Poisson/negative binomial models are also utilized. A …

Provision Of Hospital-Based Palliative Care And The Impact On Organizational And Patient Outcomes, Marisa L. Roczen

Theses and Dissertations

Hospital-based palliative care services aim to streamline medical care for patients with chronic and potentially life-limiting illnesses by focusing on individual patient needs, efficient use of hospital resources, and providing guidance for patients, patients’ families and clinical providers toward making optimal decisions concerning a patient’s care. This study examined the nature of palliative care provision in U.S. hospitals and its impact on selected organizational and patient outcomes, including hospital costs, length of stay, in-hospital mortality, and transfer to hospice. Hospital costs and length of stay are viewed as important economic indicators. Specifically, lower hospital costs may increase a hospital’s profit …

Space-Time Modelling Of Emerging Infectious Diseases: Assessing Leptospirosis Risk In Sri Lanka, Cameron C F Plouffe

Theses and Dissertations (Comprehensive)

In this research, models were developed to analyze leptospirosis incidence in Sri Lanka and its relation to rainfall. Before any leptospirosis risk models were developed, rainfall data were evaluated from an agro-ecological monitoring network for producing maps of total monthly rainfall in Sri Lanka. Four spatial interpolation techniques were compared: inverse distance weighting, thin-plate splines, ordinary kriging, and Bayesian kriging. Error metrics were used to validate interpolations against independent data. Satellite data were used to assess the spatial pattern of rainfall. Results indicated that Bayesian kriging and splines performed best in low and high rainfall, respectively. Rainfall maps generated from …

Correction Of Verication Bias Using Log-Linear Models For A Single Binaryscale Diagnostic Tests, Haresh Rochani, Hani M. Samawi, Robert L. Vogel, Jingjing Yin

Biostatistics: Faculty Publications

In diagnostic medicine, the test that determines the true disease status without an error is referred to as the gold standard. Even when a gold standard exists, it is extremely difficult to verify each patient due to the issues of costeffectiveness and invasive nature of the procedures. In practice some of the patients with test results are not selected for verification of the disease status which results in verification bias for diagnostic tests. The ability of the diagnostic test to correctly identify the patients with and without the disease can be evaluated by measures such as sensitivity, specificity and predictive …

Estimated Probability Of Becoming Alcohol Dependent: Extending A Multiparametric Approach, Olga A. Vsevolozhskaya, James C. Anthony

Biostatistics Presentations

Background: United States (US) epidemiological studies suggest that for every 5-8 who start drinking alcoholic beverages, at least one drinker will develop an alcohol dependence (AD) syndrome within the first 10 years after onset of drinking (Lopez-Quintero et al., 2011; Wagner & Anthony, 2002). Recently, we described a multiparametric functional analysis approach for new research to estimate these transition probabilities with a one-dimensional function (1D; Vsevolozhskaya & Anthony, 2015). Here, we demonstrate extension of this analysis to two-dimensional (2D) functions that combine information about number of recent drinking days and number of drinks on the typical drinking day.

Methods: Data …

Factors Impacting Transgender Patients’ Discomfort With Their Family Physicians: A Respondent-Driven Sampling Survey, Greta R. Bauer, Xuchen Zong, Ayden I. Scheim, Rebecca Hammond, Amardeep Thind

Epidemiology and Biostatistics Publications

BACKGROUND: Representing approximately 0.5% of the population, transgender (trans) persons in Canada depend on family physicians for both general and transition-related care. However, physicians receive little to no training on this patient population, and trans patients are often profoundly uncomfortable and may avoid health care. This study examined factors associated with patient discomfort discussing trans health issues with a family physician in Ontario, Canada.

METHODS: 433 trans people age 16 and over were surveyed using respondent-driven sampling for the Trans PULSE Project; 356 had a family physician. Weighted logistic regression models were fit to produce prevalence risk ratios (PRRs) via …

Pesticide Exposure, Behavior Of Farmer, And Activity Of Cholinesterase Enzyme In Blood Of Fertile Women Farmers, Deni Abdul Rahman, Zakianis Zakianis, Laila Fitria

Kesmas

Petani perempuan usia subur berisiko mengalami penurunan aktivitas kolinesterase akibat pajanan pestisida. Penelitian ini bertujuan untuk menganalisis hubungan antara pajanan pestisida dan perilaku pemajan terhadap aktivitas kolinesterase petani perempuan usia subur di Desa Kedunguter. Penelitian ini menggunakan desain potong lintang pada 94 petani perempuan usia subur tahun 2015. Pengumpulan data dilakukan secara observasi, wawancara, dan uji kolinesterase. Analisis data menggunakan uji kai kuadrat dan hasil analisis menunjukkan hubungan signifikan antara jenis pestisida, waktu kerja, penggunaan sarung tangan, perilaku mencuci tangan terhadap aktivitas kolinesterase petani perempuan usia subur. Hasil analisis pada penelitian ini menunjukkan bahwa variabel waktu kerja memiliki nilai odds …

The Use Of Earthworms And Household Organic Waste Composting Length Of Time, Abdul Khair, Lucky Herawati, Noraida Noraida, Munawar Raharja

Kesmas

Pengomposan dengan cacing tanah merupakan proses pembuatan kompos dengan melibatkan organisme makro cacing tanah. Kerja sama antara cacing tanah dengan mikroorganisme dapat memberi dampak pada proses penguraian yang dilakukan oleh mikroorganisme tersebut dibantu dengan keberadaan cacing tanah. Oleh karena bahan-bahan yang akan diurai oleh mikroorganisme telah diurai lebih dahulu oleh cacing, maka kerja mikroorganisme lebih efektif dan lebih cepat. Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan cacing tanah terhadap lama waktu pengomposan sampah organik dari rumah tangga dengan menggunakan desain penelitian eksperimen. Objek penelitian adalah seluruh sampah organik dari rumah tangga yang diambil secara acak pada satu rumah tangga. Variabel …

Riwayat Berat Badan Lahir Dengan Kejadian Stunting Pada Anak Usia Bawah Dua Tahun, Atikah Rahayu, Fahrini Yulidasari, Andini Octaviana Putri, Fauzie Rahman

Kesmas

Kabupaten Hulu Sungai Utara masih dihadapkan dengan permasalahan gizi pada anak bawah dua tahun (baduta). Salah satu masalah gizi hingga saat ini adalah stunting. Anak dengan riwayat berat badan lahir rendah (BBLR) merupakan salah satu faktor yang potensial memengaruhi pertumbuhan anak. Penelitian ini bertujuan untuk mengkaji risiko riwayat berat badan lahir dengan kejadian stunting pada anak baduta. Desain penelitian adalah potong lintang. Populasi penelitian ini merupakan ibu-ibu yang memiliki anak baduta dan besar sampel sejumlah 117 terdiri dari anak baduta. Pelaksanaan penelitian dilakukan selama tiga bulan pada bulan September – November 2014. Kategori BBLR jika riwayat berat badan lahir < 2.500 gram. Analisis data bivariat menggunakan uji kai kuadrat dan data multivariat menggunakan uji regresi logistik. Hasil analisis bivariat menunjukkan bahwa terdapat hubungan yang signifikan antara riwayat status BBLR (nilai p = 0,015) dengan stunting pada anak baduta. Berdasarkan hasil analisis multivariat, diperoleh bahwa BBLR merupakan faktor risiko yang paling dominan berhubungan dengan kejadian stunting. Anak dengan BBLR memiliki risiko 5,87 kali untuk mengalami stunting. Riwayat BBLR memiliki peranan penting dalam kejadian stunting anak baduta di wilayah Puskesmas Sungai Karias, Hulu Sungai Utara. North Hulu Sungai District is still facing nutrition problems among children under two years old. One of nutrition problems up to now is stunting. Child with low birthweight (LBW) record is one of potential factors influencing the growth of a child. This study aimed to assess any risk of LBW records with stunting incidence among children under two years old. This study used cross-sectional design. The population was mothers having children under two years old and samples amounted to 117 consisted of children under two years old. This study was conducted within three months on September – November 2014. Category of LBW was if birth weight records < 2,500 gram. Bivariate data analysis used chi-square test and multivariate data analysis used logistic regression test. The result of bivariate analysis showed a significant relation between LBW status records (p value = 0.015) with stunting incidence among children under two years old. Based on the result of multivariate analysis, LBW was the most dominating risk factor related to stunting incidence. Children with LBW had 5.87 times risk of suffering from stunting. LBW records take an important role in stunting incidence among children under two years old around Sungai Karias Primary Health Care area in North Hulu Sungai.

Penemuan Kasus Infeksi Kusta Subklinis Pada Anak Melalui Deteksi Kadar Antibodi (Igm) Anti Pgl-1, Arif Sujagat, Fardhiasih Dwi Astuti, Eva Muslimawati Saputri, Annisa Sani, Agil Dwi Prasetya

Kesmas

]Kusta merupakan penyakit menular kronis yang disebabkan Mycobacterium leprae. Indonesia menempati peringkat ketiga penyumbang kasus kusta terbanyak di dunia pada tahun 2012 – 2014. Kota Surabaya merupakan daerah endemis kusta. Penelitian ini bertujuan untuk deteksi dini kusta subklinis berdasarkan pengukuran kadar antibodi (IgM) anti PGL-1 dan mengetahui faktor-faktor yang berhubungan dengan kusta subklinis pada anak di Kota Surabaya. Penelitian analitik menggunakan desain potong lintang pada bulan April - Mei 2015. Populasi dilakukan penelitian adalah keluarga yang memiliki anggota penderita kusta. Sampel dipilih dengan teknik simple random sampling dan sebanyak 30 kepala keluarga terpilih melalui rapid school and village survey pada …

Pre-Eklampsia Berat Dan Kematian Ibu, Nova Muhani, Besral Besral

Kesmas

Pre-eklampsia berat, salah satu penyebab utama kematian ibu di Indonesia dan di RSUD Dr. H. Abdul Moeloek Lampung, merupakan penyebab kematian ibu nomor satu (47,25%). Penelitian ini bertujuan untuk mengetahui hubungan prediktor pre-eklampsi berat (PEB) yang dinilai dari tekanan darah sistolik, tekanan darah diastolik, proteiunuria, eklampsia, sindrom hemolysis, elevated liver enzymes, low platelets count (HELLP) dengan kematian ibu di RSUD Dr. H. Abdul Moeloek. Penelitian ini menggunakan desain kasus kontrol dengan jumlah sampel 60 kasus dan 120 kontrol. Data diolah dari rekam medis rumah sakit selama periode lima tahun (2010 – 2014). Hasil penelitian ini memperlihatkan bahwa sindrom HELLP memiliki …

Peran Tenaga Kesehatan Dan Keluarga Dalam Kehamilan Usia Remaja, Mery Ramadani, Dien Gusta Anggraini Nursal, Livia Ramli

Kesmas

Sebanyak 10,3% kematian tidak langsung pada ibu disebabkan kehamilan usia remaja (< 20 tahun). Di Kabupaten Tanah Datar, masih terjadi peningkatan kehamilan usia remaja dalam tiga tahun terakhir. Penelitian ini bertujuan untuk mengetahui peran tenaga kesehatan, dukungan keluarga, dan pengetahuan remaja dengan kehamilan usia remaja di wilayah kerja Puskesmas Singgalang, Kabupaten Tanah Datar tahun 2014. Penelitian dilaksanakan pada bulan Mei – Juni 2014 menggunakan desain potong lintang. Populasi adalah seluruh remaja putri berusia < 20 tahun yang telah menikah berjumlah 215 orang. Sampel berjumlah 68 orang dan pengambilan sampel dilakukan secara proporsional di delapan jorong/desa. Data dikumpulkan melalui wawancara menggunakan kuesioner. Kemudian, analisis bivariat dilakukan dengan uji kai kuadrat dan analisis multivariat dengan uji regresi logistik ganda. Hasil penelitian mendapatkan sebanyak 55,9% responden hamil di usia remaja. Sebanyak 52,9% responden kurang merasakan peran dari tenaga kesehatan, 66,2% kurang mendapat dukungan keluarga, dan 58,8% memiliki pengetahuan rendah. Didapatkan hubungan peran tenaga kesehatan (nilai p = 0,032), dukungan keluarga (nilai p = 0,025), dan tingkat pengetahuan (nilai p = 0,002) dengan kehamilan usia remaja. Dapat disimpulkan bahwa tenaga kesehatan, keluarga dan tingkat pengetahuan berperan dalam kehamilan remaja. Tenaga kesehatan perlu memberikan penyuluhan mengenai risiko kehamilan remaja kepada remaja serta keluarga. Worth 10.3% of indirect maternal death is due to teenage pregnancy (< 20 years old). In Tanah Datar District, the increase of teenage pregnancy has occured in the last three years. This study aimed to determine health worker's role, family's support and teenagers' knowledge with teenage pregnancy in work area of Singgalang Primary Health Care, Tanah Datar District in 2014. This study was conducted on May – June 2014 using cross-sectional design. Population was 215 married teenage girls < 20 years old. A total of sample was 68 selected proportionally in eight villages. Data were collected through interview using questionnaire. Then bivariate analysis was conducted using chi-square test and multivariate analysis using multiple logistic regression test. Results of study found 55.9% of respondents were pregnant in teen age. Respondents worth 52.9% got less health worker’s role, 66.2% got less family’s support and 58.8% had low level of knowledge. There was a relation found between health worker’s role (p value = 0.032), family’s support (p value = 0.025) and knowledge level (p value = 0.002) with teenage pregnancy. In conclusion, health workers, family and knowledge level play a role in teenage pregnancy. Health workers need to provide counseling concerning teenage pregnancy risks for both teenagers and families.

Pengaruh Musik Keroncong Selama Pelaksanaan Kangaroo Mother Care Terhadap Respons Fisiologis Dan Lama Rawat Bayi Dengan Berat Badan Lahir Rendah, Anita Rahmawati, Endah Marianingsih Theresia, Yuliasti Eka Purnamaningrum

Kesmas

Kangaroo mother care (KMC) merupakan metode merawat bayi berat badan lahir rendah (BBLR). Beberapa intervensi perawatan di neonatal intensive care unit seperti pijat bayi, KMC, dan mendengarkan musik bermanfaat untuk pertumbuhan bayi berupa respons fisiologis BBLR dan mengurangi lama rawat. Penelitian ini bertujuan untuk mengetahui manfaat musik keroncong terhadap respons BBLR selama KMC dan lama rawat. Rancangan penelitian adalah quasi eksperimental dengan pretest dan posttest dengan desain grup kontrol. Pada Juli - September 2014 populasi penelitian adalah ibu dan bayi BBLR yang melaksanakan KMC. Pengambilan sampel dengan purposive sampling sebanyak 60 bayi. Kriteria inklusi bayi BBLR yang ditetapkan adalah berat …

Disability Prevention Programs For Older People: Factors Associated With Medical And Nursing Care Costs, Takaaki Ikeda, Susumu Yanagawa, Kenichi Murakami, Toshiyuki Inoue, Takamasa Tsurumi

Kesmas

Penelitian ini bertujuan untuk mengklarifikasi faktor-faktor yang terkait dengan biaya medis dan perawatan lanjut usia (lansia) yang tinggal di panti sosial serta menyarankan program pencegahan disabilitas yang efektif. Total partisipan dalam penelitian ini adalah 83 orang (29 laki-laki dan 54 perempuan; usia rata-rata 81,2 ± 6,3 tahun) pada 1 November – 28 Desember 2014. Penelitian ini membandingkan biaya medis dan perawatan rata-rata per bulan dengan rata-rata nasional bagi yang berusia ≥ 65 tahun. Uji regresi logistik dilakukan untuk memeriksa keterkaitannya dengan biaya medis dan perawatan. Mereka yang pergi ke luar rumah ≥ 3 kali seminggu tiga kali lebih kecil kemungkinannya …

Monitoring For Adverse Events Post Marketing Approval Of Drugs, Karl E. Peace, Macaulay Okwuokenye

Biostatistics: Faculty Publications

This brief communication provides information to those developing monitoring plans for serious adverse events (SAE’s) following regulatory approval of a new drug. In addition, we (1) illustrate how many patients would need to be treated in order to have high confidence of seeing at least 1 pre-specified SAE, (2) show that absence of proof of a SAE is not proof of absence of that SAE, and (3) identify statistical methodology that could be used for formal statistical monitoring of SAE’s.

Nested Partially-Latent, Class Models For Dependent Binary Data, Estimating Disease Etiology, Zhenke Wu, Maria Deloria-Knoll, Scott L. Zeger

Johns Hopkins University, Dept. of Biostatistics Working Papers

The Pneumonia Etiology Research for Child Health (PERCH) study seeks to use modern measurement technology to infer the causes of pneumonia for which gold-standard evidence is unavailable. The paper describes a latent variable model designed to infer from case-control data the etiology distribution for the population of cases, and for an individual case given his or her measurements. We assume each observation is drawn from a mixture model for which each component represents one cause or disease class. The model addresses a major limitation of the traditional latent class approach by taking account of residual dependence among multivariate binary outcome …

Identification And Survival Outcomes Of A Cohort Of Patients With Cancer Of Unknown Primary In Ontario, Canada., Chong S Kim, Malek B Hannouf, Sisira Sarma, George B Rodrigues, Peter K Rogan, Salaheddin M Mahmud, Eric Winquist, Muriel Brackstone, Gregory S Zaric

Epidemiology and Biostatistics Publications

BACKGROUND: Cancer of unknown primary origin (CUP) is defined by the presence of pathologically identified metastatic disease without clinical or radiological evidence of a primary tumour. Our objective was to identify incident cases of CUP in Ontario, Canada, and determine the influence of histology and sites of metastases on overall survival (OS).

MATERIAL AND METHODS: We used the Ontario Cancer Registry (OCR) and the Same-Day Surgery and Discharge Abstract Database (SDS/DAD) to identify patients diagnosed with CUP in Ontario between 1 January 2000, and 31 December 2005. Patient diagnostic information, including histology and survival data, was obtained from the OCR. …

Dynapenic Obesity And The Effect On Long-Term Physical Function And Quality Of Life: Data From The Osteoarthritis Initiative, John A. Batsis, Alicia J. Zbehlik, Dawna Pidgeon, Stephen J. Bartels

Dartmouth Scholarship

Obesity is associated with functional impairment, institutionalization, and increased mortality risk in elders. Dynapenia is defined as reduced muscle strength and is a known independent predictor of adverse events and disability. The synergy between dynapenia and obesity leads to worse outcomes than either independently. We identified the impact of dynapenic obesity in a cohort at risk for and with knee osteoarthritis on function.

Validation Of A New Predictive Risk Model: Measuring The Impact Of The Major Modifiable Risks Of Death For Patients And Populations, Stephen S. Lim, Emily Carnahan, Eugene C. Nelson, Catherine W. Gillespie, Ali H. Mokdad, Christopher J. L. Murray, Elliott S. Fisher

Dartmouth Scholarship

Background: Modifiable risks account for a large fraction of disease and death, but clinicians and patients lack tools to identify high risk populations or compare the possible benefit of different interventions.

Methods: We used data on the distribution of exposure to 12 major behavioral and biometric risk factors inthe US population, mortality rates by cause, and estimates of the proportional hazards of risk factor exposure from published systematic reviews to develop a risk prediction model that estimates an adult's 10 year mortality risk compared to a population with optimum risk factors. We compared predicted risk to observed mortality in 8,241 …

A Machine Learning Approach To Post-Market Surveillance Of Medical Devices, Jonathan Bates, Shu-Xia Li, Craig Parzynski, Ronald Coifman, Harlan Krumholz, Joseph Ross

Yale Day of Data

Post-market surveillance is a collection of processes and activities used by product manufacturers and regulators, such as the U.S. Food and Drug Administration (FDA) to monitor the safety and effectiveness of medical devices once they are available for use “on the market”. These activities are designed to generate information to identify poorly performing devices and other safety problems, accurately characterize real-world device performance and clinical outcomes, and facilitate the development of new devices, or new uses for existing devices. Typically, a device is monitored by comparing adverse events in the exposed population to a matched unexposed population. This research considers …

Preparedness Of Hospitals In The Republic Of Ireland For An Influenza Pandemic, An Infection Control Perspective, Mary Reidy, Fiona Ryan, Dervla Hogan, Seán Lacey, Claire Buckley

Department of Mathematics Publications

When an influenza pandemic occurs most of the population is susceptible and attack rates can range as high as 40–50 %. The most important failure in pandemic planning is the lack of standards or guidelines regarding what it means to be ‘prepared’. The aim of this study was to assess the preparedness of acute hospitals in the Republic of Ireland for an influenza pandemic from an infection control perspective.