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Clinical Epidemiology Commons

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Full-Text Articles in Clinical Epidemiology

Decreasing Barriers For Teens: Evaluation Of A New Teenage Pregnancy Prevention Strategy In School-Based Clinics, Abbey C. Sidebottom, Amanda Birnbaum, Sarah S. Nafstad Nov 2003

Decreasing Barriers For Teens: Evaluation Of A New Teenage Pregnancy Prevention Strategy In School-Based Clinics, Abbey C. Sidebottom, Amanda Birnbaum, Sarah S. Nafstad

Department of Public Health Scholarship and Creative Works

Sidebottom et al seek to evaluate the effects of the change in distribution systems on students' receipt of requested contraceptives and demand for contraceptive school-based clinics (SBC). The result of the study reveals that the average number of requests per student was higher under the voucher system, possibly as a consequence of expires vouchers resulting in repeated requests. The findings also suggest that SBCs could go a step further in reducing adolescents' barriers to accessing contraceptives by adopting an on-site direct delivery system..


Adjusting For Non-Ignorable Verification Bias In Clinical Studies For Alzheimer’S Disease, Xiao-Hua Zhou, Pete Castelluccio Jul 2003

Adjusting For Non-Ignorable Verification Bias In Clinical Studies For Alzheimer’S Disease, Xiao-Hua Zhou, Pete Castelluccio

UW Biostatistics Working Paper Series

A common problem for comparing the relative accuracy of two screening tests for Alzheimer’s disease (D) in a two-stage design study is verification bias. If the verification bias can be assumed to be ignorable, Zhou and Higgs (2000) have proposed a maximum likelihood approach to compare the relative accuracy of screening tests in a two-stage design study. However, if the verification mechanism also depends on the unobserved disease status, the ignorable assumption does not hold. In this paper, we discuss how to use a profile likelihood approach to compare the relative accuracy of two screening tests for AD without assuming …


Identifying Target Populations For Screening Or Not Screening Using Logic Regression, Holly Janes, Margaret S. Pepe, Charles Kooperberg, Polly Newcomb May 2003

Identifying Target Populations For Screening Or Not Screening Using Logic Regression, Holly Janes, Margaret S. Pepe, Charles Kooperberg, Polly Newcomb

UW Biostatistics Working Paper Series

Colorectal cancer remains a significant public health concern despite the fact that effective screening procedures exist and that the disease is treatable when detected at early stages. Numerous risk factors for colon cancer have been identified, but none are very predictive alone. We sought to determine whether there are certain combinations of risk factors that distinguish well between cases and controls, and that could be used to identify subjects at particularly high or low risk of the disease to target screening. Using data from the Seattle site of the Colorectal Cancer Family Registry (C-CFR), we fit logic regression models to …


Semiparametric Receiver Operating Characteristic Analysis To Evaluate Biomarkers For Disease, Tianxi Cai, Margaret S. Pepe Jan 2003

Semiparametric Receiver Operating Characteristic Analysis To Evaluate Biomarkers For Disease, Tianxi Cai, Margaret S. Pepe

UW Biostatistics Working Paper Series

The receiver operating characteristic (ROC) curve is a popular method for characterizing the accuracy of diagnostic tests when test results are not binary. Various methodologies for estimating and comparing ROC curves have been developed. One approach, due to Pepe, uses a parametric regression model with the baseline function specified up to a finite-dimensional parameter. In this article we extend the regression models by allowing arbitrary nonparametric baseline functions. We also provide asymptotic distribution theory and procedures for making statistical inference. We illustrate our approach with dataset from a prostate cancer biomarker study. Simulation studies suggest that the extra flexibility inherent …