Download or read book Design and Analysis of Group randomized Trials written by David M. Murray and published by Monographs in Epidemiology and. This book was released on 1998 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Community or group-randomized trials, which are usually done to evaluate the effect of health promotion effors. It reviews the underlying issues, describes the most widely used research design, and presents the many approaches to analysis that are now available.
Download or read book Small Clinical Trials written by Institute of Medicine and published by National Academies Press. This book was released on 2001-01-01 with total page 221 pages. Available in PDF, EPUB and Kindle. Book excerpt: Clinical trials are used to elucidate the most appropriate preventive, diagnostic, or treatment options for individuals with a given medical condition. Perhaps the most essential feature of a clinical trial is that it aims to use results based on a limited sample of research participants to see if the intervention is safe and effective or if it is comparable to a comparison treatment. Sample size is a crucial component of any clinical trial. A trial with a small number of research participants is more prone to variability and carries a considerable risk of failing to demonstrate the effectiveness of a given intervention when one really is present. This may occur in phase I (safety and pharmacologic profiles), II (pilot efficacy evaluation), and III (extensive assessment of safety and efficacy) trials. Although phase I and II studies may have smaller sample sizes, they usually have adequate statistical power, which is the committee's definition of a "large" trial. Sometimes a trial with eight participants may have adequate statistical power, statistical power being the probability of rejecting the null hypothesis when the hypothesis is false. Small Clinical Trials assesses the current methodologies and the appropriate situations for the conduct of clinical trials with small sample sizes. This report assesses the published literature on various strategies such as (1) meta-analysis to combine disparate information from several studies including Bayesian techniques as in the confidence profile method and (2) other alternatives such as assessing therapeutic results in a single treated population (e.g., astronauts) by sequentially measuring whether the intervention is falling above or below a preestablished probability outcome range and meeting predesigned specifications as opposed to incremental improvement.
Download or read book Cluster Randomised Trials written by Richard J. Hayes and published by CRC Press. This book was released on 2017-07-06 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cluster Randomised Trials, Second Edition discusses the design, conduct, and analysis of trials that randomise groups of individuals to different treatments. It explores the advantages of cluster randomisation, with special attention given to evaluating the effects of interventions against infectious diseases. Avoiding unnecessary mathematical detail, the book covers basic concepts underlying the use of cluster randomisation, such as direct, indirect, and total effects. In the time since the publication of the first edition, the use of cluster randomised trials (CRTs) has increased substantially, which is reflected in the updates to this edition. There are greatly expanded sections on randomisation, sample size estimation, and alternative designs, including new material on stepped wedge designs. There is a new section on handling ordinal outcome data, and an appendix with descriptions and/or generating code of the example data sets. Although the book mainly focuses on medical and public health applications, it shows that the rigorous evidence of intervention effects provided by CRTs has the potential to inform public policy in a wide range of other areas. The book encourages readers to apply the methods to their own trials, reproduce the analyses presented, and explore alternative approaches.
Download or read book How to Design Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research written by Michael J. Campbell and published by John Wiley & Sons. This book was released on 2014-05-27 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: A complete guide to understanding cluster randomised trials Written by two researchers with extensive experience in the field, this book presents a complete guide to the design, analysis and reporting of cluster randomised trials. It spans a wide range of applications: trials in developing countries, trials in primary care, trials in the health services. A key feature is the use of R code and code from other popular packages to plan and analyse cluster trials, using data from actual trials. The book contains clear technical descriptions of the models used, and considers in detail the ethics involved in such trials and the problems in planning them. For readers and students who do not intend to run a trial but wish to be a critical reader of the literature, there are sections on the CONSORT statement, and exercises in reading published trials. Written in a clear, accessible style Features real examples taken from the authors’ extensive practitioner experience of designing and analysing clinical trials Demonstrates the use of R, Stata and SPSS for statistical analysis Includes computer code so the reader can replicate all the analyses Discusses neglected areas such as ethics and practical issues in running cluster randomised trials How to Design, Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research provides an excellent reference tool and can be read with profit by statisticians, health services researchers, systematic reviewers and critical readers of cluster randomised trials.
Download or read book Design and Analysis of Cluster Randomization Trials in Health Research written by Allan Donner and published by Wiley. This book was released on 2010-05-17 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A cluster randomization trial is one in which intact social units, or clusters of individuals, are randomized to different intervention groups. Trials randomizing clusters have become particularly widespread in the evaluation of non-therapeutic interventions, including lifestyle modification, educational programmes and innovations in the provision of health care. The increasing popularity of this design among health researchers over the past two decades has led to an extensive body of methodology on the subject. This is the first book to present a systematic and united treatment of this topic; it contains distinctive chapters on the history of cluster randomized trials, ethical issues and reporting guidelines.
Download or read book Field Trials of Health Interventions written by Peter G. Smith and published by Oxford University Press, USA. This book was released on 2015 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: "IEA, International Epidemiological Association, Welcome Trust."
Download or read book Designing Randomised Trials in Health Education and the Social Sciences written by D. Torgerson and published by Springer. This book was released on 2008-03-13 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book focuses on the design of rigorous trials rather than their statistical underpinnings, with chapters on: pragmatic designs; placebo designs; preference approaches; unequal allocation; economics; analytical approaches; randomization methods. It also includes a detailed description of randomization procedures and different trial designs.
Download or read book Power Analysis of Trials with Multilevel Data written by Mirjam Moerbeek and published by CRC Press. This book was released on 2015-07-01 with total page 275 pages. Available in PDF, EPUB and Kindle. Book excerpt: Power Analysis of Trials with Multilevel Data is a valuable reference for anyone who wants to perform power calculations on trials with hierarchical data. It provides a thorough overview of power analysis, familiarizing you with terminology and notation, outlining the key concepts of statistical power and power analysis, and covering all common hierarchical designs.
Download or read book ClinicalTrials written by Curtis L. Meinert and published by OUP USA. This book was released on 2012-03-27 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: The classic, definitive guide to the design, conduct, and analysis of randomized clinical trials.
Download or read book Sample Size Calculations for Clustered and Longitudinal Outcomes in Clinical Research written by Chul Ahn and published by CRC Press. This book was released on 2014-12-09 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate sample size calculation ensures that clinical studies have adequate power to detect clinically meaningful effects. This results in the efficient use of resources and avoids exposing a disproportionate number of patients to experimental treatments caused by an overpowered study. Sample Size Calculations for Clustered and Longitudinal Outcomes in Clinical Research explains how to determine sample size for studies with correlated outcomes, which are widely implemented in medical, epidemiological, and behavioral studies. The book focuses on issues specific to the two types of correlated outcomes: longitudinal and clustered. For clustered studies, the authors provide sample size formulas that accommodate variable cluster sizes and within-cluster correlation. For longitudinal studies, they present sample size formulas to account for within-subject correlation among repeated measurements and various missing data patterns. For multiple levels of clustering, the level at which to perform randomization actually becomes a design parameter. The authors show how this can greatly impact trial administration, analysis, and sample size requirement. Addressing the overarching theme of sample size determination for correlated outcomes, this book provides a useful resource for biostatisticians, clinical investigators, epidemiologists, and social scientists whose research involves trials with correlated outcomes. Each chapter is self-contained so readers can explore topics relevant to their research projects without having to refer to other chapters.
Download or read book A Practical Guide to Cluster Randomised Trials in Health Services Research written by Sandra Eldridge and published by John Wiley & Sons. This book was released on 2012-02-20 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cluster randomised trials are trials in which groups (or clusters) of individuals are randomly allocated to different forms of treatment. In health care, these trials often compare different ways of managing a disease or promoting healthy living, in contrast to conventional randomised trials which randomise individuals to different treatments, classically comparing new drugs with a placebo. They are increasingly common in health services research. This book addresses the statistical, practical, and ethical issues arising from allocating groups of individuals, or clusters, to different interventions. Key features: Guides readers through the stages of conducting a trial, from recruitment to reporting. Presents a wide range of examples with particular emphasis on trials in health services research and primary care, with both principles and techniques explained. Topics are specifically presented in the order in which investigators think about issues when they are designing a trial. Combines information on the latest developments in the field together with a practical guide to the design and implementation of cluster randomised trials. Explains principles and techniques through numerous examples including many from the authors own experience. Includes a wide range of references for those who wish to read further. This book is intended as a practical guide, written for researchers from the health professions including doctors, psychologists, and allied health professionals, as well as statisticians involved in the design, execution, analysis and reporting of cluster randomised trials. Those with a more general interest will find the plentiful examples illuminating.
Download or read book The Prevention and Treatment of Missing Data in Clinical Trials written by National Research Council and published by National Academies Press. This book was released on 2010-12-21 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Randomized clinical trials are the primary tool for evaluating new medical interventions. Randomization provides for a fair comparison between treatment and control groups, balancing out, on average, distributions of known and unknown factors among the participants. Unfortunately, these studies often lack a substantial percentage of data. This missing data reduces the benefit provided by the randomization and introduces potential biases in the comparison of the treatment groups. Missing data can arise for a variety of reasons, including the inability or unwillingness of participants to meet appointments for evaluation. And in some studies, some or all of data collection ceases when participants discontinue study treatment. Existing guidelines for the design and conduct of clinical trials, and the analysis of the resulting data, provide only limited advice on how to handle missing data. Thus, approaches to the analysis of data with an appreciable amount of missing values tend to be ad hoc and variable. The Prevention and Treatment of Missing Data in Clinical Trials concludes that a more principled approach to design and analysis in the presence of missing data is both needed and possible. Such an approach needs to focus on two critical elements: (1) careful design and conduct to limit the amount and impact of missing data and (2) analysis that makes full use of information on all randomized participants and is based on careful attention to the assumptions about the nature of the missing data underlying estimates of treatment effects. In addition to the highest priority recommendations, the book offers more detailed recommendations on the conduct of clinical trials and techniques for analysis of trial data.
Download or read book Introduction to Randomized Controlled Clinical Trials written by John N.S. Matthews and published by CRC Press. This book was released on 2006-06-26 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Evidence from randomized controlled clinical trials is widely accepted as the only sound basis for assessing the efficacy of new medical treatments. Statistical methods play a key role in all stages of these trials, including their justification, design, and analysis. This second edition of Introduction to Randomized Controlled Clinical Trials prov
Download or read book Simulating Data with SAS written by Rick Wicklin and published by SAS Institute. This book was released on 2013 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data simulation is a fundamental technique in statistical programming and research. Rick Wicklin's Simulating Data with SAS brings together the most useful algorithms and the best programming techniques for efficient data simulation in an accessible how-to book for practicing statisticians and statistical programmers. This book discusses in detail how to simulate data from common univariate and multivariate distributions, and how to use simulation to evaluate statistical techniques. It also covers simulating correlated data, data for regression models, spatial data, and data with given moments. It provides tips and techniques for beginning programmers, and offers libraries of functions for advanced practitioners. As the first book devoted to simulating data across a range of statistical applications, Simulating Data with SAS is an essential tool for programmers, analysts, researchers, and students who use SAS software. This book is part of the SAS Press program.
Download or read book Planning Clinical Research written by Robert A. Parker and published by Cambridge University Press. This book was released on 2016-10-12 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: Planning a clinical study is much more than determining the basic study design. Who will you be studying? How do you plan to recruit your study subjects? How do you plan to retain them in the study? What data do you plan to collect? How will you obtain this data? How will you minimize bias? All these decisions must be consistent with the ethical considerations of studying people. This book teaches how to choose the best design for your question. Drawing on their many years working in clinical research, Nancy G. Berman and Robert A. Parker guide readers through the essential elements of study planning to help get them started. The authors offer numerous examples to illustrate the key decisions needed, describing what works, what does not work, and why. Written specifically for junior investigators beginning their research careers, this guide will also be useful to senior investigators needing to review specific topics.
Download or read book Design and Analysis of Pragmatic Trials written by Song Zhang and published by CRC Press. This book was released on 2023-05-16 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book begins with an introduction of pragmatic cluster randomized trials (PCTs) and reviews various pragmatic issues that need to be addressed by statisticians at the design stage. It discusses the advantages and disadvantages of each type of PCT, and provides sample size formulas, sensitivity analyses, and examples for sample size calculation. The generalized estimating equation (GEE) method will be employed to derive sample size formulas for various types of outcomes from the exponential family, including continuous, binary, and count variables. Experimental designs that have been frequently employed in PCTs will be discussed, including cluster randomized designs, matched-pair cluster randomized design, stratified cluster randomized design, stepped-wedge cluster randomized design, longitudinal cluster randomized design, and crossover cluster randomized design. It demonstrates that the GEE approach is flexible to accommodate pragmatic issues such as hierarchical correlation structures, different missing data patterns, randomly varying cluster sizes, etc. It has been reported that the GEE approach leads to under-estimated variance with limited numbers of clusters. The remedy for this limitation is investigated for the design of PCTs. This book can assist practitioners in the design of PCTs by providing a description of the advantages and disadvantages of various PCTs and sample size formulas that address various pragmatic issues, facilitating the proper implementation of PCTs to improve health care. It can also serve as a textbook for biostatistics students at the graduate level to enhance their knowledge or skill in clinical trial design. Key Features: Discuss the advantages and disadvantages of each type of PCTs, and provide sample size formulas, sensitivity analyses, and examples. Address an unmet need for guidance books on sample size calculations for PCTs; A wide variety of experimental designs adopted by PCTs are covered; The sample size solutions can be readily implemented due to the accommodation of common pragmatic issues encountered in real-world practice; Useful to both academic and industrial biostatisticians involved in clinical trial design; Can be used as a textbook for graduate students majoring in statistics and biostatistics.
Download or read book Complex Interventions in Health written by David A. Richards and published by Routledge. This book was released on 2015-04-17 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Health and human services currently face a series of challenges – such as aging populations, chronic diseases and new endemics – that require highly complex responses, and take place in multiple care environments including acute medicine, chronic care facilities and the community. Accordingly, most modern health care interventions are now seen as ‘complex interventions’ – activities that contain a number of component parts with the potential for interactions between them which, when applied to the intended target population, produce a range of possible and variable outcomes. This in turn requires methodological developments that also take into account changing values and attitudes related to the situation of patients’ receiving health care. The first book to place complex interventions within a coherent system of research enquiry, this work is designed to help researchers understand the research processes involved at each stage of developing, testing, evaluating and implementing complex interventions, and assist them to integrate methodological activities to produce secure, evidence-based health care interventions. It begins with conceptual chapters which set out the complex interventions framework, discuss the interrelation between knowledge development and evidence, and explore how mixed methods research contributes to improved health. Structured around the influential UK Medical Research Council guidance for use of complex interventions, four sections, each comprised of bite-sized chapters written by multidisciplinary experts in the area, focus on: - Developing complex interventions - Assessing the feasibility of complex interventions and piloting them - Evaluating complex interventions - Implementing complex interventions. Accessible to students and researchers grappling with complex interventions, each substantive chapter includes an introduction, bulleted learning objectives, clinical examples, a summary and further reading. The perspectives of various stakeholders, including patients, families and professionals, are discussed throughout as are the economic and ethical implications of methods. A vital companion for health research, this book is suitable for readers from multidisciplinary disciplines such as medical, nursing, public health, health services research, human services and allied healthcare backgrounds.
