Epidemiology Commons^™

Faktor-Faktor Yang Mempengaruhi Kematian Pasien Penyakit Jantung Koroner Di Pusat Jantung Nasional Harapan Kita Tahun 2004, Fatmah A. Gobel, Renti Mahkota

Kesmas

Menurut estimasi WHO, sekitar 50% dari 12 juta penduduk dunia meninggal akibat penyakit jantung dan pembuluh darah. Faktor prognosis pasien PJK dapat diubah dan dikendalikan, dan memungkinkan untuk mencegah kematian akibat PJK. Penelitian ini bertujuan mengetahui faktor prognosis yang berhubungan dengan terjadinya kematian pasien PJK di PJN Harapan Kita Tahun 2004, menggunakan data sekunder (data rekam medik pasien). Variabel-variabel yang diteliti meliputi variabel independen (jaminan pembayaran, asal daerah/kawasan, penyakit penyerta hipertensi, diabetes melitus, dislipidemia dan riwayat PJK sebelumnya) dan variabel kovariat (umur, jenis kelamin, pendidikan dan pekerjaan). Desain epidemiologi yang digunakan adalah analitik kasus kontrol dengan jumlah kasus 130, kontrol …

A Likelihood Based Method For Real Time Estimation Of The Serial Interval And Reproductive Number Of An Epidemic, Laura Forsberg White, Marcello Pagano

Harvard University Biostatistics Working Paper Series

No abstract provided.

What Is The Cost To Employers Of Direct Medical Care For Chronic Obstructive Pulmonary Disease?, Tursynbek Nurmagambetov, Adam Atherly, Seymour Williams, Fernando Holguin, David M. Mannino, Stephen C. Redd

David M. Mannino

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality in the United States. In 2000, an estimated 10.5 million people had COPD, of which more than 7.2 million were from the under-age 65 employed population. The prevalence of COPD in the workforce population was substantial with 46.5% of current employment among adults having the disease. However, the cost burden in the employed population is unknown. We examined COPD prevalence and costs in a large employment-based population. Using claims data from 1999 to 2003, we estimated the cost associated with COPD-related hospitalizations, emergency department visits, outpatient services, …

Stability Analysis For An Seir Age-Structured Epidemic Model Under Vaccination, M. El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

An SEIR age-structured epidemic model is investigated when susceptible and immune individuals are vaccinated indiscriminately and the force of infection of proportionate mixing type. We determine the steady states and obtain an explicitly computable threshold condition, and then study the stability of the steady states.

Global Stability Results And Well Posedness Of An Si Age-Structured Epidemic Model With Vertical Transmission, M. El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

An SI age-structured epidemic model for a vertically as well as horizontally transmitted disease is investigated when the fertility and mortality rates depend on age and the force of infection of proportionate mixing assumption type. We prove the well posedness of the model as well as the global stability for endemic equilibriums.

A Multilevel Analysis Of Socioeconomic Status And Prostate Cancer Risk, Maureen Sanderson, Ann L. Coker, Adriana Perez, Xianglin L. Du, Gerson Peltz, Mary K. Fadden

Health & Biomedical Sciences Faculty Publications and Presentations

PURPOSE

We investigated whether prostate cancer was associated with socioeconomic status (SES) at the individual level, area level, or a combination of both levels.

METHODS

This population-based case–control study of prostate cancer in men aged 65 to 79 years was conducted between 2000 and 2002 in South Carolina. Complete interviews were available for 407 incident prostate cancer cases and 393 controls (with respective response rates of 61% and 64%). We used educational level to measure individual-level SES and a composite variable capturing income and education from 2000 Census data to measure area-level SES.

RESULTS

After adjustment for race, age, geographic …

Spatio-Temporal Analysis Of Areal Data And Discovery Of Neighborhood Relationships In Conditionally Autoregressive Models, Subharup Guha, Louise Ryan

Harvard University Biostatistics Working Paper Series

No abstract provided.

Semiparametric Regression Of Multi-Dimensional Genetic Pathway Data: Least Squares Kernel Machines And Linear Mixed Models, Dawei Liu, Xihong Lin, Debashis Ghosh

Harvard University Biostatistics Working Paper Series

No abstract provided.

The Effect Of Timing Of Radiotherapy After Breast-Conserving Surgery In Patients With Positive Or Close Resection Margins, Young Age, And Node-Negative Disease, With Long Term Follow-Up, Olga Vujovic, Anil Cherian, Edward Yu, A. Dar, Larry Stitt, Francisco Perera

Edward Yu

Purpose: The aim of this study was to determine the effect of timing of radiotherapy after conservative breast surgery on local recurrence in women with positive resection margins and young age, treated without systemic therapy. Methods and materials: A total of 568 patients with T1 and T2, N0 breast cancer were treated with breast-conserving surgery and breast irradiation, between January 1, 1985, and December 31, 1992, at the London Regional Cancer Centre. 63 patients (11.1%) had positive/close resection margins (< 2 mm) and 48 patients (8.4%) were age < or = 40 years. For patients with positive resection margins, the time intervals from breast surgery to breast irradiation used for analysis were, 0 to 8 weeks, > 8 to 12 weeks and > 12 weeks. For patients < or = 40 years, the intervals used for analysis were 0 to 8 weeks and > 8 weeks. Results: Median follow up was 11.2 years. For patients …

Pengembangan Sistem Informasi Program Kusta Berbasis Geografis Di Kabupaten Cirebon Tahun 2005, Haeria Haeria

Kesmas

Kusta yang disebabkan oleh infeksi Mycobacterium leprae merupakan penyakit menular dengan masalah yang sangat kompleks. Tiga tahun terakhir, Kabupaten Cirebon yang melaporkan 1.207 penderita kusta (Prevalence 1,69/10.000 penduduk), belum mencapai tahap eliminasi sehinga penularan masuh berlansung. Tujuan penelitian mengembangan sistem informasi kusta berbasis geografis yang dapat dijadikan solusi percepatan eliminasi kusta di Kabupaten Cirebon. Metoda yang digunakan adalah System Development Life Cycle, yaitu planning, analysis, design, implementation, maintenance dan evaluation system. Hal tersebut dilakukan dengan memadukan konsep Data Base Management System dan data spasial. Hasil analisis sistem dapat mengidentifikasi masalah manajemen penanggulangan kusta serta alternatif solusi pada level …

Faktor-Faktor Prognosis Kematian Tetanus Neonatorum Di Rs Kabupaten Indramayu Dan Kabupaten Cirebon, Lili Tantijati, Krisnawati Bantas

Kesmas

Angka Kematian Bayi (AKB) di Indonesia masih tetap tinggi. Berdasarkan Biro Pusat Statistik (BPS) pada tahun 1995 adalah 55/1.000 kelahiran hidup. Salah satu penyebab utama dari kematian bayi adalah penyakit tetanus neonatorum. Tujuan dari penelitian ini adalah untuk menentukan hubungan antara usia saat ditemukan adanya indikasi penyakit neonatarum pada bayi dengan timbulnya kematian yang disebabkan oleh tetanus neonatorum pada bayi-bayi tersebut di Kabupaten Indramayu pada tahun 1996-2001. Penelitian ini menggunakan disain studi epidemiologi kasus-kontrol dengan perbandingan kasus dan kontrol 1:1. Jumlah sampel, 160 penderita tetanus neonatorum. Populasi studi adalah penderita tetanus neonatorum yang dirawat di RSD kabupaten Cirebon dan kabupaten …

Prevalensi Dan Determinan Hipertensi Di Pulau Jawa, Tahun 2004, Zamhir Setiawan

Kesmas

Hipertensi merupakan faktor risiko utama kardiovaskuler yang merupakan penyebab utama kematian di seluruh dunia. Peningkatan umur harapan hidup dan perubahan gaya hidup meningkatkan faktor risiko hipertensi di berbagai negara. Tujuan penelitian ini (1) Mengetahui prevalensi hipertensi dan penyebarannya di Pulau Jawa tahun 2004. (2) Mengetahui faktor-faktor sosiodemografi yang berhubungan dengan kejadian hipertensi. (3) Mengetahui kontribusi dan dampak potensial masing masing faktor tersebut. Penelitian dengan rancangan studi Ekologi Multilevel ini menggabungkan variabel tingkat pengukuran individu dengan tingkat pengukuran ekologi dalam analisis bersama, dengan unit analisis individu. Analisis kontekstual dilakukan melalui kerangka konsep hipertensi, menggunakan metode analisis regresi logistik ganda, dengan status …

Statistical Analysis Of Air Pollution Panel Studies: An Illustration, Holly Janes, Lianne Sheppard, Kristen Shepherd

UW Biostatistics Working Paper Series

The panel study design is commonly used to evaluate the short-term health effects of air pollution. Standard statistical methods for analyzing longitudinal data are available, but the literature reveals that the techniques are not well understood by practitioners. We illustrate these methods using data from the 1999 to 2002 Seattle panel study. Marginal, conditional, and transitional approaches for modeling longitudinal data are reviewed and contrasted with respect to their parameter interpretation and methods for accounting for correlation and dealing with missing data. We also discuss and illustrate techniques for controlling for time-dependent and time-independent confounding, and for exploring and summarizing …

Biologic Interaction And Their Identification, Tyler J. Vanderweele, James Robins

COBRA Preprint Series

The definitions of a biologic interaction and causal interdependence are reconsidered in light of a sufficient-component cause framework. Various conditions and statistical tests are derived for the presence of biologic interactions. The conditions derived are sufficient but not necessary for the presence of a biologic interaction. Through a series of examples it is made evident that in the context of monotonic effects, but not in general, the conditions which are derived are closely related but not identical to effect modification on the risk difference scale.

A Theory Of Sufficient Cause Interactions, Tyler J. Vanderweele, James M. Robins

COBRA Preprint Series

Sufficient-component causes are discussed within the potential outcome framework so as to formalize notions of sufficient causes, synergism and sufficient cause interactions. Doing so allows for the derivation of counterfactual conditions and statistical tests for detecting the presence of sufficient cause interactions. Under the assumption of monotonic effects, more powerful statistical tests for sufficient cause interactions can be derived. The statistical tests derived for sufficient cause interactions are compared with and contrasted to interaction terms in standard statistical models.

Exploiting Gene-Environment Independence For Analysis Of Case-Control Studies: An Empirical Bayes Approach To Trade Off Between Bias And Efficiency , Bhramar Mukherjee

The University of Michigan Department of Biostatistics Working Paper Series

Standard prospective logistic regression analysis of case-control data often leads to very imprecise estimates of gene-environment interactions due to small numbers of cases or controls in cells of crossing genotype and exposure. In contrast, modern ``retrospective'' methods, including the celebrated ``case-only'' approach, can estimate the interaction parameters much more precisely, but they can be seriously biased when the underlying assumption of gene-environment independence is violated. In this article, we propose a novel approach to analyze case-control data that can relax the gene-environment independence assumption using an empirical Bayes (EB) framework. In the special case, involving a binary gene and a …

Girls' Perception Of Physical Environmental Factors And Transportation: Reliability And Association With Physical Activity And Active Transport To School, Kelly R. Evenson, Amanda Birnbaum, Ariane L. Bedimo-Rung, James Sallis, Carolyn C. Voorhees, Kimberly Ring, John P. Elder

Department of Public Health Scholarship and Creative Works

Background

Preliminary evidence suggests that the physical environment and transportation are associated with youth physical activity levels. Only a few studies have examined the association of physical environmental factors on walking and bicycling to school. Therefore, the purpose of this study was (1) to examine the test-retest reliability of a survey designed for youth to assess perceptions of physical environmental factors (e.g. safety, aesthetics, facilities near the home) and transportation, and (2) to describe the associations of these perceptions with both physical activity and active transport to school.

Methods

Test and retest surveys, administered a median of 12 days later, …

Spatial Cluster Detection For Censored Outcome Data, Andrea J. Cook, Diane Gold, Yi Li

Harvard University Biostatistics Working Paper Series

No abstract provided.

Extending Marginal Structural Models Through Local, Penalized, And Additive Learning, Daniel Rubin, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Marginal structural models (MSMs) allow one to form causal inferences from data, by specifying a relationship between a treatment and the marginal distribution of a corresponding counterfactual outcome. Following their introduction in Robins (1997), MSMs have typically been fit after assuming a semiparametric model, and then estimating a finite dimensional parameter. van der Laan and Dudoit (2003) proposed to instead view MSM fitting not as a task of semiparametric parameter estimation, but of nonparametric function approximation. They introduced a class of causal effect estimators based on mapping loss functions suitable for the unavailable counterfactual data to those suitable for the …

Changing The Burden Of Copd Mortality, David M. Mannino, Victor A. Kiri

David M. Mannino

COPD is a major cause of mortality and morbidity worldwide with an estimated 2.75 million deaths in 2000 (fourth leading cause of death). In addition to the considerable morbidity and mortality associated with COPD, this disease incurs significant healthcare and societal costs. Current COPD guidelines acknowledge that the following can improve COPD mortality: smoking cessation; long-term oxygen therapy; and lung volume reduction surgery in small subsets of COPD patients. To date, no randomized controlled trials have demonstrated an effect of pharmacological treatment on mortality, although several observational studies suggest that both long-acting bronchodilators and inhaled corticosteroids may provide a survival …

The Role Of Body Mass Index And Diabetes In The Development Of Acute Organ Failure And Subsequent Mortality In An Observational Cohort, Katarina Slynkova, David M. Mannino, Greg S. Martin, Richard S. Morehead, Dennis E. Doherty

David M. Mannino

Introduction

Several studies have shown a correlation between body mass index (BMI) and both the development of critical illness and adverse outcomes in critically ill patients. The goal of our study was to examine this relationship prospectively with particular attention to the influence of concomitant diabetes mellitus (DM).

Methods

We analyzed data from 15,408 participants in the Atherosclerosis Risk in Communities (ARIC) study for this analysis. BMI and the presence of DM were defined at baseline. We defined 'acute organ failure' as those subjects who met a standard definition with diagnostic codes abstracted from hospitalization records. Outcomes assessed included the …

Structural Inference In Transition Measurement Error Models For Longitudinal Data, Wenqin Pan, Xihong Lin, Donglin Zeng

Harvard University Biostatistics Working Paper Series

No abstract provided.

Estimation In Semiparametric Transition Measurement Error Models For Longitudinal Data, Wenqin Pan, Donglin Zeng, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

Nonparametric Regression Using Local Kernel Estimating Equations For Correlated Failure Time Data, Zhangsheng Yu, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

Causal Inference In Hybrid Intervention Trials Involving Treatment Choice, Qi Long, Rod Little, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

A Comparison Of Methods For Estimating The Causal Effect Of A Treatment In Randomized Clinical Trials Subject To Noncompliance, Rod Little, Qi Long, Xihong Lin

Harvard University Biostatistics Working Paper Series

No abstract provided.

Epidemiologi Diskriptif Penyakit Avian Flu Di Lima Provinsi Di Indonesia, 2005-2006, Ajeng Tias Endarti, Ratna Djuwita

Kesmas

Jumlah kasus flu burung pada manusia meningkat sangat pesat. Studi ini bertujuan untuk mengetahui gambaran epidemiologi penyakit flu burung (Avian Influenza/AI) pada kejadian luar biasa di 5 provinsi Indonesia in 2005-2006. Studi ini mengunakan sumber data sekunder data surveilens, sub direktorat Surveilens, Depkes RI, pada periode Juli 2005-2006. Dari 28 kasus konfirmasi ditemukan banyak pada pria (57.1%). Sekitar 89.3% kasus memperlihatkan gejala demam tinggi (>38°C), batuk dan masalah pernapasan dan sekitar 80% diantaranya meninggal dunia. Gejala tersebut mengindikasikan kerusakan jaringan paru-paru pada tubuh penderita. Berdasarkan laporan hasil pemeriksaan laboratorium, terlihat bahwa 60.7% penderita mengalami penurunan kadar leukosit (leucopenia) dan …

Infestasi Kecacingan Pada Anak Sd Di Kecamatan Sei Bingai Langkat, Sumut, 2005, Limin Ginting

Kesmas

Indonesia masih menghadapi masalah kesehatan yang berhubungan dengan kondisi lingkungan yang jelek, seperti infestasi cacing usus yang ditularkan melalui tanah (Soil Transmitted Helminths). Infestasi cacing pada anak akan mengganggu pertumbuhan, menurunkan kemampuan fisik, produktifitas belajar dan intelektualitas. Hasil Pemeriksaan yang dilakukan di beberapa SD di Kecamatan Stabat dan Kecamatan Hinai menemukan prevalensi kecacingan berada pada kisaran 30-60%. Penelitian ini bertujuan untuk menilai prevalensi infestasi kecacingan pada anak SD di Kecamatan Sei Bingai, Kabupaten Langkat serta mengetahui faktor-faktor yang mempengaruhinya. Penelitian dengan disain studi kasus kontrol ini dilakukan di 4 SD Kecamatan Sei Bingai, Kabupaten Langkat, Propinsi Sumatera Utara. Populasi adalah …

Relative Risk Regression In Medical Research: Models, Contrasts, Estimators, And Algorithms, Thomas Lumley, Richard Kronmal, Shuangge Ma

UW Biostatistics Working Paper Series

The relative risk or prevalence ratio is a natural and familiar summary of association between a binary outcome and an exposure or intervention. For rare events, the relative risk can be approximately estimated by logistic regression. For common events estimation is more difficult. We review proposed estimation algorithms for relative risk regression. Some of these give inconsistent estimates or invalid standard errors. We show that the methods that give correct inference can be viewed as arising from a family of quasilikelihood estimating functions for the same generalized linear model, differing in their efficiency and in their robustness to outlying values …

Investigating Mediation When Counterfactuals Are Not Metaphysical: Does Sunlight Uvb Exposure Mediate The Effect Of Eyeglasses On Cataracts?, Brian Egleston, Daniel O. Scharfstein, Beatriz Munoz, Sheila West

Johns Hopkins University, Dept. of Biostatistics Working Papers

We investigate the degree to which a reduction in ocular sunlight ultra-violet B (UVB) exposure mediates a relationship between wearing eyeglasses and a decreased risk of cataracts. An estimand is proposed in which causal effects are estimated locally within strata based on potential UVB exposure without glasses and the degree to which glasses use reduces UVB exposure. We take advantage of the structure of the data in which the counterfactual UVB exposures if the participants in the study who wore glasses had not worn glasses are considered observable.