Download or read book Statistical Evaluation of Diagnostic Performance written by Kelly H. Zou and published by CRC Press. This book was released on 2016-04-19 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: Statistical evaluation of diagnostic performance in general and Receiver Operating Characteristic (ROC) analysis in particular are important for assessing the performance of medical tests and statistical classifiers, as well as for evaluating predictive models or algorithms. This book presents innovative approaches in ROC analysis, which are releva

Download or read book The Statistical Evaluation of Medical Tests for Classification and Prediction written by Margaret Sullivan Pepe and published by OUP Oxford. This book was released on 2003-03-13 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes statistical techniques for the design and evaluation of research studies on medical diagnostic tests, screening tests, biomarkers and new technologies for classification and prediction in medicine.

Download or read book Statistical Methods in Diagnostic Medicine written by Xiao-Hua Zhou and published by John Wiley & Sons. This book was released on 2014-08-21 with total page 597 pages. Available in PDF, EPUB and Kindle. Book excerpt: Praise for the First Edition " . . . the book is a valuable addition to the literature in the field, serving as a much-needed guide for both clinicians and advanced students."—Zentralblatt MATH A new edition of the cutting-edge guide to diagnostic tests in medical research In recent years, a considerable amount of research has focused on evolving methods for designing and analyzing diagnostic accuracy studies. Statistical Methods in Diagnostic Medicine, Second Edition continues to provide a comprehensive approach to the topic, guiding readers through the necessary practices for understanding these studies and generalizing the results to patient populations. Following a basic introduction to measuring test accuracy and study design, the authors successfully define various measures of diagnostic accuracy, describe strategies for designing diagnostic accuracy studies, and present key statistical methods for estimating and comparing test accuracy. Topics new to the Second Edition include: Methods for tests designed to detect and locate lesions Recommendations for covariate-adjustment Methods for estimating and comparing predictive values and sample size calculations Correcting techniques for verification and imperfect standard biases Sample size calculation for multiple reader studies when pilot data are available Updated meta-analysis methods, now incorporating random effects Three case studies thoroughly showcase some of the questions and statistical issues that arise in diagnostic medicine, with all associated data provided in detailed appendices. A related web site features Fortran, SAS®, and R software packages so that readers can conduct their own analyses. Statistical Methods in Diagnostic Medicine, Second Edition is an excellent supplement for biostatistics courses at the graduate level. It also serves as a valuable reference for clinicians and researchers working in the fields of medicine, epidemiology, and biostatistics.

Download or read book A Statistical Evaluation Methodology for Measuring the Diagnostic Performance of Medical Expert Systems written by Dorothy Christine Georgakis and published by . This book was released on 1990 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Assessment of Diagnostic Technology in Health Care written by Institute of Medicine and published by National Academies Press. This book was released on 1989-02-01 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Technology assessment can lead to the rapid application of essential diagnostic technologies and prevent the wide diffusion of marginally useful methods. In both of these ways, it can increase quality of care and decrease the cost of health care. This comprehensive monograph carefully explores methods of and barriers to diagnostic technology assessment and describes both the rationale and the guidelines for meaningful evaluation. While proposing a multi-institutional approach, it emphasizes some of the problems involved and defines a mechanism for improving the evaluation and use of medical technology and essential resources needed to enhance patient care.

Download or read book Improving Diagnosis in Health Care written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2015-12-29 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Getting the right diagnosis is a key aspect of health care - it provides an explanation of a patient's health problem and informs subsequent health care decisions. The diagnostic process is a complex, collaborative activity that involves clinical reasoning and information gathering to determine a patient's health problem. According to Improving Diagnosis in Health Care, diagnostic errors-inaccurate or delayed diagnoses-persist throughout all settings of care and continue to harm an unacceptable number of patients. It is likely that most people will experience at least one diagnostic error in their lifetime, sometimes with devastating consequences. Diagnostic errors may cause harm to patients by preventing or delaying appropriate treatment, providing unnecessary or harmful treatment, or resulting in psychological or financial repercussions. The committee concluded that improving the diagnostic process is not only possible, but also represents a moral, professional, and public health imperative. Improving Diagnosis in Health Care, a continuation of the landmark Institute of Medicine reports To Err Is Human (2000) and Crossing the Quality Chasm (2001), finds that diagnosis-and, in particular, the occurrence of diagnostic errorsâ€"has been largely unappreciated in efforts to improve the quality and safety of health care. Without a dedicated focus on improving diagnosis, diagnostic errors will likely worsen as the delivery of health care and the diagnostic process continue to increase in complexity. Just as the diagnostic process is a collaborative activity, improving diagnosis will require collaboration and a widespread commitment to change among health care professionals, health care organizations, patients and their families, researchers, and policy makers. The recommendations of Improving Diagnosis in Health Care contribute to the growing momentum for change in this crucial area of health care quality and safety.

Download or read book Biostatistics for Radiologists written by Francesco Sardanelli and published by Springer Science & Business Media. This book was released on 2009-03-31 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this book is to present statistical problems and methods in a friendly way to radiologists, emphasizing statistical issues and methods most frequently used in radiological studies (e.g., nonparametric tests, analysis of intra- and interobserver reproducibility, comparison of sensitivity and specificity among different imaging modality, difference between clinical and screening application of diagnostic tests, ect.). The tests will be presented starting from a radiological "problem" and all examples of statistical methods applications will be "radiological".

Download or read book ROC Curves for Continuous Data written by Wojtek J. Krzanowski and published by CRC Press. This book was released on 2009-05-21 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since ROC curves have become ubiquitous in many application areas, the various advances have been scattered across disparate articles and texts. ROC Curves for Continuous Data is the first book solely devoted to the subject, bringing together all the relevant material to provide a clear understanding of how to analyze ROC curves.The fundamenta

Download or read book Diagnostic Meta Analysis written by Giuseppe Biondi-Zoccai and published by Springer. This book was released on 2019-01-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first exclusively devoted to the systematic synthesis of diagnostic test accuracy studies. It builds upon the major recent developments in reporting standards, search methods, and, in particular, statistical tools specifically devoted to diagnostic studies. In addition, it borrows extensively from the latest advances in systematic reviews and meta-analyses of intervention studies. After a section dedicated to methods for designing reviews, synthesizing evidence and appraising inconsistency in research, the application of these approaches is demonstrated in the context of case studies from various clinical disciplines. Diagnosis is central in medical decision-making, and in many other fields of human endeavor, such as education and psychology. The plurality of sources of evidence on diagnostic test accuracy poses a huge challenge for practitioners and researchers, as do the multiple dimensions of evidence validity, which include sensitivity, specificity, predictive values, and likelihood ratios. This book offers an invaluable resource for anyone aiming to improve decision-making processes in diagnosis, classification or risk prognostication, from epidemiologists to biostatisticians, radiologists, laboratory physicians and graduate students, as any physician interested in refining his methodological skills in clinical diagnosis.

Download or read book Statistical Methods for Combining Diagnostic Tests and Performance Evaluation Metrics written by Chengning Zhang (Ph.D.) and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In biomedical studies, it is usually the case that several diagnostic tests can be performedon an individual or multiple disease markers are available simultaneously, and that many of them may be associated with the clinical outcome. In practice, a single test or marker often has limited diagnostic performance. Therefore, it is important to combine multiple sources of information available to achieve higher classification performance. This dissertation focuses on statistical methods for combining multiple diagnostic tests and the corresponding performance evaluation metrics. In the first project, we provide a survey of the current state of the art in methods for combining multiple tests. We categorize existing methods into three general groups and conduct extensive simulation studies to compare the performance of different combination methods. The reviewed methods serve as benchmark for developing new combination approaches in the following projects. In the second project, we consider the problem of combining multiple tests whose values are missing at random (MAR). In addition, we aim to exploit the known monotonicity relationship between the input variables and the disease outcome for gains in diagnostic accuracy. We develop a novel likelihood-based approach to monotone classification that accounts for missing inputs in a natural and principled way. The risk score function is obtained through the nonparametric maximum likelihood estimation (NPMLE). A novel expectation-maximization (EM)-type algorithm is devised to compute the NPMLE by treating the monotonicity-constrained risk score function as a cumulative distribution for a latent random vector. Through simulation studies and a real data example, we demonstrate that the proposed method outperforms state-of-the-art methods for combining multiple inputs under monotonic assumption, especially when the inputs contain missing data. We illustrate our approach with a dataset from a recent nonalcoholic fatty liver disease (NALFD) study. In the third project, our approach established in the second part is extended to the scenario where one covariate is randomly censored. The proposed approach consists of two steps. In step one, we use a Cox proportional hazards model for the distribution of the censored covariate given other covariates in the model, this conditional distribution is used for calculating the observed likelihood of data. In step two, a similar expectation maximization (EM)-type algorithm is devised, based on observed data likelihood from step one, to compute the NPMLE of the monotonicity-constrained risk score function. Through simulation studies, we demonstrate that the proposed method outperforms the simple but inefficient complete-case analysis as well as the substitution methods. We apply our method to the data set from a primary biliary cirrhosis (PBC) study conducted at Mayo Clinic. The proposed methods in part two and three can be extended to multi-class cases, where the labels have an inherent order but no meaningful numeric distance between them. A natural question arises as to how to evaluate the classification performance under such setting. Therefore, in the fourth project, we consider the problem of performance evaluation metrics for ordinal classification. We propose three novel performance evaluation metrics that better capture the ordinality of the outcomes. The first metric is adapted from the area under the receiver operating characteristic (ROC) curve (AUC), while the latter two are simple and interpretable generalizations of the Harrell's concordance index (C-INDEX). Moreover, we show the optimality of the AUC based metrics through Neyman-Pearson lemma. We conduct extensive simulation studies to confirm the usefulness of the proposed performance metrics for ordinal classification.

Download or read book Finite Mixture Models written by Geoffrey McLachlan and published by John Wiley & Sons. This book was released on 2004-03-22 with total page 419 pages. Available in PDF, EPUB and Kindle. Book excerpt: An up-to-date, comprehensive account of major issues in finitemixture modeling This volume provides an up-to-date account of the theory andapplications of modeling via finite mixture distributions. With anemphasis on the applications of mixture models in both mainstreamanalysis and other areas such as unsupervised pattern recognition,speech recognition, and medical imaging, the book describes theformulations of the finite mixture approach, details itsmethodology, discusses aspects of its implementation, andillustrates its application in many common statisticalcontexts. Major issues discussed in this book include identifiabilityproblems, actual fitting of finite mixtures through use of the EMalgorithm, properties of the maximum likelihood estimators soobtained, assessment of the number of components to be used in themixture, and the applicability of asymptotic theory in providing abasis for the solutions to some of these problems. The author alsoconsiders how the EM algorithm can be scaled to handle the fittingof mixture models to very large databases, as in data miningapplications. This comprehensive, practical guide: * Provides more than 800 references-40% published since 1995 * Includes an appendix listing available mixture software * Links statistical literature with machine learning and patternrecognition literature * Contains more than 100 helpful graphs, charts, and tables Finite Mixture Models is an important resource for both applied andtheoretical statisticians as well as for researchers in the manyareas in which finite mixture models can be used to analyze data.

Download or read book Principles and Practice of Clinical Trials written by Steven Piantadosi and published by Springer Nature. This book was released on 2022-07-19 with total page 2573 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is a comprehensive major reference work for our SpringerReference program covering clinical trials. Although the core of the Work will focus on the design, analysis, and interpretation of scientific data from clinical trials, a broad spectrum of clinical trial application areas will be covered in detail. This is an important time to develop such a Work, as drug safety and efficacy emphasizes the Clinical Trials process. Because of an immense and growing international disease burden, pharmaceutical and biotechnology companies continue to develop new drugs. Clinical trials have also become extremely globalized in the past 15 years, with over 225,000 international trials ongoing at this point in time. Principles in Practice of Clinical Trials is truly an interdisciplinary that will be divided into the following areas: 1) Clinical Trials Basic Perspectives 2) Regulation and Oversight 3) Basic Trial Designs 4) Advanced Trial Designs 5) Analysis 6) Trial Publication 7) Topics Related Specific Populations and Legal Aspects of Clinical Trials The Work is designed to be comprised of 175 chapters and approximately 2500 pages. The Work will be oriented like many of our SpringerReference Handbooks, presenting detailed and comprehensive expository chapters on broad subjects. The Editors are major figures in the field of clinical trials, and both have written textbooks on the topic. There will also be a slate of 7-8 renowned associate editors that will edit individual sections of the Reference.

Download or read book Observer Performance Methods for Diagnostic Imaging written by Dev P. Chakraborty and published by CRC Press. This book was released on 2017-12-14 with total page 591 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gives an accessible overview of R programming for medical imaging and the methods of observer performance testing. Explains the fundamental statistical concepts. Reinforces learning using worked problems and R software code, in addition to examples that utilize standalone ROC software. Starts with basic ROC analysis and builds to extensions of ROC methods for solving more complex but clinically realistic tasks. Emphasizes psychophysical models of observer performance (e.g., binormal model, contaminated binormal model, proper ROC model), and demonstrates how they can give better results than from purely statistical approaches. Supplementary tools and materials available at: www.devchakraborty.com; www.expertcadanalytics.com.

Download or read book The Evidence Base of Clinical Diagnosis written by J. Andre Knottnerus and published by BMJ Books. This book was released on 2009-01-26 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: This unique book presents a framework for the strategy and methodology of diagnostic research, in relation to its relevance for practice. Now in its second edition The Evidence Base of Clinical Diagnosis has been fully revised and extended with new chapters covering the STARD guidelines (STAndards for the Reporting of Diagnostic accuracy studies) and the multivariable analysis of diagnostic data. With contributions from leading international experts in evidence-based medicine, this book is an indispensable guide on how to conduct and interpret studies in clinical diagnosis. It will serve as a valuable resource for all investigators who want to embark on diagnostic research and for clinicians, practitioners and students who want to learn more about its principles and the relevant methodological options available.

Download or read book Cognitive Diagnostic Assessment for Education written by Jacqueline Leighton and published by Cambridge University Press. This book was released on 2007-05-14 with total page 353 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the current push toward educational reform, there is great potential for innovation and change, particularly in large scale testing. One area where change is possible is in cognitive diagnostic assessment. Researchers in educational measurement and cognitive psychology are finally in a position to design tests targeted specifically for providing valuable information about students' cognitive strengths and weaknesses. This self-contained volume organizes what is known about cognitive diagnostic assessment in education, including its conceptual and philosophical basis, methods, and applications. The complete list of topics includes educational demand, philosophical rationale, construct validity, cognitive methods, test construction, statistical models, and unresolved issues (e.g., how to best translate diagnostic information into teaching practices). Leighton and Gierl present a comprehensive and up-to-date examination of cognitive diagnostic assessment in education.

Download or read book Handbook of Diagnostic Classification Models written by Matthias von Davier and published by Springer Nature. This book was released on 2019-10-11 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook provides an overview of major developments around diagnostic classification models (DCMs) with regard to modeling, estimation, model checking, scoring, and applications. It brings together not only the current state of the art, but also the theoretical background and models developed for diagnostic classification. The handbook also offers applications and special topics and practical guidelines how to plan and conduct research studies with the help of DCMs. Commonly used models in educational measurement and psychometrics typically assume a single latent trait or at best a small number of latent variables that are aimed at describing individual differences in observed behavior. While this allows simple rankings of test takers along one or a few dimensions, it does not provide a detailed picture of strengths and weaknesses when assessing complex cognitive skills. DCMs, on the other hand, allow the evaluation of test taker performance relative to a potentially large number of skill domains. Most diagnostic models provide a binary mastery/non-mastery classification for each of the assumed test taker attributes representing these skill domains. Attribute profiles can be used for formative decisions as well as for summative purposes, for example in a multiple cut-off procedure that requires mastery on at least a certain subset of skills. The number of DCMs discussed in the literature and applied to a variety of assessment data has been increasing over the past decades, and their appeal to researchers and practitioners alike continues to grow. These models have been used in English language assessment, international large scale assessments, and for feedback for practice exams in preparation of college admission testing, just to name a few. Nowadays, technology-based assessments provide increasingly rich data on a multitude of skills and allow collection of data with respect to multiple types of behaviors. Diagnostic models can be understood as an ideal match for these types of data collections to provide more in-depth information about test taker skills and behavioral tendencies.

Download or read book Statistics Applied to Clinical Trials written by Ton J. Cleophas and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1948 the first randomized controlled trial was published by the English Medical Research Council in the British Medical Journal. Until then, observations had been uncontrolled. Initially, trials frequently did not confirm the hypotheses to be tested. This phenomenon was attributed to low sensitivity due to small samples, as well as inappropriate hypotheses based on biased prior trials. Additional flaws were recognized and, subsequently, were better accounted for: carryover effects due to insufficient washout from previous treatments, time effects due to external factors and the natural history of the condition under study, bias due to asymmetry between treatment groups, lack of sensitivity due to a negative correlation between treatment responses, and so on. Such flaws, mainly of a technical nature, have been largely corrected and led to trials after 1970 being of significantly higher quality. The past decade has focused, in addition to technical aspects, on the need for circumspection in the planning and conducting of clinical trials. As a consequence, prior to approval, clinical trial protocols are now routinely scrutinized by different circumstantial organs, including ethics committees, institutional and federal review boards, national and international scientific organizations, and monitoring committees charged with conducting interim analyses. This book not only explains classical statistical analyses of clinical trials, but also addresses relatively novel issues, including equivalence testing, interim analyses, sequential analyses, and meta-analyses, and provides a framework of the best statistical methods currently available for such purposes. This book is not only useful for investigators involved in the field of clinical trials, but also for all physicians who wish to better understand the data of trials as currently published.