Biostatistics Commons^™

Efektivitas Dan Efisiensi Sistem Informasi Keluarga Berencana Di Puskesmas, Aragar Putri, Besral Besral

Kesmas

Efisiensi dan efektivitas sistem informasi keluarga berencana (KB)-kesehatan yang telah disosialisasikan sejak tahun 2007 dibandingkan dengan sistem yang lama belum diketahui. Suatu penelitian survei dilakukan di empat provinsi, yaitu DKI Jakarta, Lampung, Kalimatan Tengah, dan Bali. Di tiap provinsi dipilih dua kabupaten/kota dan pada tiap kabupaten/kota dipilih dua puskesmas (kecamatan) yang sudah menerapkan sistem informasi KB-kesehatan tersebut. Pengumpulan data dilakukan pada bulan Juni-September 2008. Penelitian ini menemukan bahwa efektivitas dan efisiensi sistem informasi KB yang baru cukup baik, 77,8% responden menyatakan lebih efektif atau sangat lebih efektif dan 66,7% responden menyatakan lebih efisien atau sangat lebih efisien dibandingkan dengan sistem …

Bate Curve In Assessment Of Clinical Utility Of Predictive Biomarkers, Xiao-Hua Zhou, Yunbei Ma

UW Biostatistics Working Paper Series

In this paper, for time-to-event data, we propose a new statistical framework for casual inference in evaluating clinical utility of predictive biomarkers and in selecting an optimal treatment for a particular patient. This new casual framework is based on a new concept, called Biomarker Adjusted Treatment Effect (BATE) curve, which can be used to represent the clinical utility of a predictive biomarker and select an optimal treatment for one particular patient. We then propose semi-parametric methods for estimating the BATE curves of biomarkers and establish asymptotic results of the proposed estimators for the BATE curves. We also conduct extensive simulation …

Tmle: An R Package For Targeted Maximum Likelihood Estimation, Susan Gruber, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Targeted maximum likelihood estimation (TMLE) presents an approach for construction of an efficient double-robust semi-parametric substitution estimator of a target feature of the data generating distribution, such as a statistical association measure or a causal effect parameter. tmle is a recently developed R package that implements TMLE for estimation of the effect of a binary treatment at a single point in time on an outcome of interest, controlling for user supplied covariates: the additive treatment effect, the relative risk, the odds ratio. The package allows outcome data with missingness, and experimental units that contribute repeated records of the point-treatment data …

Causal Inference Under Multiple Versions Of Treatment, Tyler J. Vanderweele, Miguel A. Hernan

COBRA Preprint Series

In this article we discuss the no-multiple-versions-of-treatment assumption and extend the potential outcomes framework to accommodate causal inference under violations of this assumption. A variety of examples are discussed in which the assumption may be violated. Identification results are provided for the overall treatment effect and the effect of treatment on the treated when multiple versions of treatment are present and also for the causal effect comparing a version of one treatment to some other version of the same or a different treatment. Further identification and interpretative results are given for cases in which a treatment variable is dichotomized to …

30-Year Trends In Heart Failure In Patients Hospitalized With Acute Myocardial Infarction, David Mcmanus, Marcello Chinali, Jane Saczynski, Joel Gore, Jorge Yarzebski, Frederick Spencer, Darleen Lessard, Robert Goldberg

Jorge L. Yarzebski

Despite significant advances in its treatment, acute myocardial infarction (AMI) remains an important cause of heart failure (HF). Contemporary data remain lacking, however, describing long-term trends in incidence rates, demographic and clinical profiles, and outcomes of patients who develop HF as a complication of AMI. Our study sample consisted of 11,061 residents of the Worcester (Massachusetts) metropolitan area hospitalized with AMI at all greater Worcester hospitals in 15 annual study periods from 1975 to 2005. Overall, 32.4% of patients (n = 3,582) with AMI developed new-onset HF during their acute hospitalization. Patients who developed HF were generally older, more likely …

Recent Trends In The Incidence, Treatment, And Outcomes Of Patients With Stemi And Nstemi, David Mcmanus, Joel Gore, Jorge Yarzebski, Frederick Spencer, Darleen Lessard, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: despite the widespread use of electrocardiographic changes to characterize patients presenting with acute myocardial infarction, little is known about recent trends in the incidence rates, treatment, and outcomes of patients admitted for acute myocardial infarction further classified according to the presence of ST-segment elevation. The objectives of this population-based study were to examine recent trends in the incidence and death rates associated with the 2 major types of acute myocardial infarction in residents of a large central Massachusetts metropolitan area. METHODS: We reviewed the medical records of 5383 residents of the Worcester (MA) metropolitan area hospitalized for either ST-segment …

Declining Length Of Stay For Patients Hospitalized With Ami: Impact On Mortality And Readmissions, Jane Saczynski, Darleen Lessard, Frederick Spencer, Jerry Gurwitz, Joel Gore, Jorge Yarzebski, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Length of hospital stay after acute myocardial infarction decreased significantly in the 1980s and 1990s. Whether length of stay has continued to decrease during the 2000s, and the impact of decreasing length of stay on rehospitalization and mortality, is unclear. We describe decade-long (1995-2005) trends in length of stay after acute myocardial infarction, and examine whether declining length of stay has impacted early rehospitalization and postdischarge mortality in a population-based sample of hospitalized patients.

METHODS: The study sample consisted of 4184 patients hospitalized with acute myocardial infarction in a central New England metropolitan area during 6 annual periods (1995, …

Management And Outcomes Of Renal Disease And Acute Myocardial Infarction, Paul Santolucito, Dennis Tighe, David Mcmanus, Jorge Yarzebski, Darleen Lessard, Joel Gore, Robert Goldberg

Jorge L. Yarzebski

BACKGROUND: Contemporary trends in the management and outcomes of chronic kidney disease patients who develop an acute myocardial infarction have not been adequately described, particularly from the more generalizable perspective of a population-based investigation. METHODS: The study population consisted of 6219 residents of the Worcester, Massachusetts, metropolitan area who were hospitalized with acute myocardial infarction in 6 annual periods between 1995 and 2005. Patients were categorized as having preserved kidney function (n=3154), mild to moderate chronic kidney disease (n=2313), or severe chronic kidney disease (n=752) at the time of hospital admission. RESULTS: Patients with chronic kidney disease were more likely …

Non-Homogeneous Markov Process Models With Incomplete Observations: Application To A Dementia Disease Study, Xiao-Hua Zhou, Baojiang Chen

UW Biostatistics Working Paper Series

Identifying risk factors for transition rates among normal cognition, mildly cognitive impairment, dementia and death in an Alzheimer's disease study is very important. It is known that transition rates among these states are strongly time dependent. While Markov process models are often used to describe these disease progressions, the literature mainly focuses on time homogeneous processes, and limited tools are available for dealing with non-homogeneity. Further, patients may choose when they want to visit the clinics, which creates informative observations. In this paper, we develop methods to deal with non-homogeneous Markov processes through time scale transformation when observation times are …

Doubly Robust Estimates For Binary Longitudinal Data Analysis With Missing Response And Missing Covariates, Baojiang Chen, Xiao-Hua Zhou

UW Biostatistics Working Paper Series

Longitudinal studies often feature incomplete response and covariate data. Likelihood-based methods such as the EM algorithm give consistent estimators for model parameters when data are missing at random provided that the response model and the missing covariate model are correctly specified; but we do not need to specify the missing data mechanism. An alternative method is the weighted estimating equation which gives consistent estimators if the missing data and response models are correctly specified; but we do not need to specify the distribution of the covariates that have missing values. In this paper we develop a doubly robust estimation method …

Semiparametric Estimation Of The Covariate-Specific Roc Curve In Presence Of Ignorable Verification Bias, Danping Liu, Xiao-Hua Zhou

UW Biostatistics Working Paper Series

Covariate-specific ROC curves are often used to evaluate the classification accuracy of a medical diagnostic test or a biomarker, when the accuracy of the test is associated with certain covariates. In many large-scale screening tests, the gold standard is subject to missingness due to high cost or harmfulness to the patient. In this paper, we propose a semiparametric estimation method for the covariate-specific ROC curves with a partial missing gold standard. A location-scale model is constructed for the test result to model the covariates' effect, but the residual distributions are left unspecified. Thus the baseline and link functions of the …

Evaluating Markers For Treatment Selection Based On Survival Time, Xiao Song, Xiao-Hua Zhou

UW Biostatistics Working Paper Series

For many medical conditions there are several treatment options available to patients. We consider evaluating markers based on a simple treatment selection policy that incorporates information on the patient's marker value exceeding a threshold. Although traditional regression methods may assess the effect of the marker and treatment on outcomes, it is appealing to quantify more directly the potential impact on the population of using the marker to select treatment. A useful tool is the selection impact (SI) curve proposed by Song and Pepe (2004, \textit{Biometrics} \textbf{60}, 874--883) for binary outcomes. However, this approach does not deal with continuous outcomes, nor …

Caffeinated Coffee, Decaffeinated Coffee And Endometrial Cancer Risk: A Prospective Cohort Study Among Us Postmenopausal Women, Ayush Giri, Susan R. Sturgeon, Nicole Luisi, Elizabeth Bertone-Johnson, Raji Balasubramanian, Katherine W. Reeves

Biostatistics and Epidemiology Faculty Publications Series

There is plausible biological evidence as well as epidemiologic evidence to suggest coffee consumption may lower endometrial cancer risk. We evaluated the associations between self-reported total coffee, caffeinated coffee and decaffeinated coffee, and endometrial cancer risk using the Women’s Health Initiative Observational Study Research Materials obtained from the National Heart, Lung, and Blood Institute Biological Specimen and Data Repository Coordinating Center. Our primary analyses included 45,696 women and 427 incident endometrial cancer cases, diagnosed over a total of 342,927 person-years of follow-up. We used Cox-proportional hazard models to evaluate coffee consumption and endometrial cancer risk. Overall, we did not find …

Angiogenic Biomarkers For Risk Stratification In Women With Suspected Preeclampsia, Andreea Balan, Heather Young, Linda Ojo, Jennifer Keller, Sharon Maynard

Epidemiology Faculty Posters and Presentations

This poster presents the results of a single-center prospective cohort study of 315 pregnant women who presented to George Washington University Hospital Labor and Delivery service with a clinical suspicion of preeclampsia between February 2007 and November 2011. Informed consent was obtained. Baseline demographic information and medical history was collected on each patient including maternal age, ethnicity, body mass index, tobacco and other substance use, gestational age, medical problems and obstetric history. Serum samples were obtained from each enrolled subject within 24 hours of admission, and sFlt1, PlGF and sEng ELISA assays were performed in duplicate by a blinded laboratory …

Prevalence Of Piscine Myocarditis Virus (Pmcv) In Marine Fish Species, Torstein Tengs Dr.

Dr. Torstein Tengs

No abstract.

Dose-Finding For Multi-Drug Combinations, Nolan A. Wages

Nolan A. Wages

No abstract provided.

Flexible Distributed Lag Models Using Random Functions With Application To Estimating Mortality Displacement From Heat-Related Deaths, Roger D. Peng, Matthew J. Heaton

Roger D. Peng

No abstract provided.

Compound Treatments, Transportability, And The Structural Causal Model: The Power And Simplicity Of Causal Graphs., Maya Petersen

Maya Petersen

No abstract provided.

Generalized Benjamini-Hochberg Procedures Using Spacings, Debashis Ghosh

Debashis Ghosh

For the problem of multiple testing, the Benjamini-Hochberg (B-H) procedure has become a very popular method in applications. We show how the B-H procedure can be interpreted as a test based on the spacings corresponding to the p-value distributions. Using this equivalence, we develop a class of generalized B-H procedures that maintain control of the false discovery rate in finite-samples. We also consider the effect of correlation on the procedure; simulation studies are used to illustrate the methodology.

Software For Assumption Weighting For Meta-Analysis Of Genomic Data, Debashis Ghosh, Yihan Li

Debashis Ghosh

This is the software that accompanies Li and Ghosh, "Assumption weighting for incorporating heterogeneity into meta-analysis of genomic data."