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 Cluster Randomised Trials written by Richard J. Hayes and published by CRC Press. This book was released on 2017-07-06 with total page 362 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 Field Trials of Health Interventions written by Peter G. Smith and published by . This book was released on 2015 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an open access title available under the terms of a CC BY-NC 4.0 International licence. It is free to read at Oxford Scholarship Online and offered as a free PDF download from OUP and selected open access locations. Before new interventions are released into disease control programmes, it is essential that they are carefully evaluated in field trials'. These may be complex and expensive undertakings, requiring the follow-up of hundreds, or thousands, of individuals, often for long periods. Descriptions of the detailed procedures and methods used in the trials that have been conducted have rarely been published. A consequence of this, individuals planning such trials have few guidelines available and little access to knowledge accumulated previously, other than their own. In this manual, practical issues in trial design and conduct are discussed fully and in sufficient detail, that Field Trials of Health Interventions may be used as a toolbox' by field investigators. It has been compiled by an international group of over 30 authors with direct experience in the design, conduct, and analysis of field trials in low and middle income countries and is based on their accumulated knowledge and experience. Available as an open access book via Oxford Medicine Online, this new edition is a comprehensive revision, incorporating the new developments that have taken place in recent years with respect to trials, including seven new chapters on subjects ranging from trial governance, and preliminary studies to pilot testing.

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 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 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 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 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 Randomized Controlled Trials written by Alehandro R. Jadad and published by John Wiley & Sons. This book was released on 2007-07-23 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Randomized controlled trials are one of the most powerful and revolutionary tools of research. This book is a convenient and accessible description of the underlying principles and practice of randomized controlled trials and their role in clinical decision-making. Structured in a jargon-free question-and-answer format, each chapter provides concise and understandable information on a different aspect of randomized controlled trials, from the basics of trial design and terminology to the interpretation of results and their use in driving evidence-based medicine. The authors end each chapter with their musings, going beyond the evidence or citations, and sometimes even beyond orthodox correctness to share their thoughts and concerns about different aspects of randomized controlled trials, and their role within the health system. Updated to include insights from the last decade, this second edition challenges over-reliance on randomized controlled trials by debating their strengths and limitations and discussing their optimal use in modern healthcare. It also includes a new and increasingly relevant chapter on the ethics of randomized trials. World renowned writers and thinkers Drs Jadad and Enkin bring you this invaluable book for busy health professionals who wish to understand the theory of randomized controlled trials and their influence on clinical, research or policy decisions.

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.

Download or read book Cochrane Handbook for Systematic Reviews of Interventions written by Julian P. T. Higgins and published by Wiley. This book was released on 2008-11-24 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: Healthcare providers, consumers, researchers and policy makers are inundated with unmanageable amounts of information, including evidence from healthcare research. It has become impossible for all to have the time and resources to find, appraise and interpret this evidence and incorporate it into healthcare decisions. Cochrane Reviews respond to this challenge by identifying, appraising and synthesizing research-based evidence and presenting it in a standardized format, published in The Cochrane Library (www.thecochranelibrary.com). The Cochrane Handbook for Systematic Reviews of Interventions contains methodological guidance for the preparation and maintenance of Cochrane intervention reviews. Written in a clear and accessible format, it is the essential manual for all those preparing, maintaining and reading Cochrane reviews. Many of the principles and methods described here are appropriate for systematic reviews applied to other types of research and to systematic reviews of interventions undertaken by others. It is hoped therefore that this book will be invaluable to all those who want to understand the role of systematic reviews, critically appraise published reviews or perform reviews themselves.

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 Randomization in Clinical Trials written by William F. Rosenberger and published by John Wiley & Sons. This book was released on 2015-11-23 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Praise for the First Edition “All medical statisticians involved in clinical trials should read this book...” - Controlled Clinical Trials Featuring a unique combination of the applied aspects of randomization in clinical trials with a nonparametric approach to inference, Randomization in Clinical Trials: Theory and Practice, Second Edition is the go-to guide for biostatisticians and pharmaceutical industry statisticians. Randomization in Clinical Trials: Theory and Practice, Second Edition features: Discussions on current philosophies, controversies, and new developments in the increasingly important role of randomization techniques in clinical trials A new chapter on covariate-adaptive randomization, including minimization techniques and inference New developments in restricted randomization and an increased focus on computation of randomization tests as opposed to the asymptotic theory of randomization tests Plenty of problem sets, theoretical exercises, and short computer simulations using SAS® to facilitate classroom teaching, simplify the mathematics, and ease readers’ understanding Randomization in Clinical Trials: Theory and Practice, Second Edition is an excellent reference for researchers as well as applied statisticians and biostatisticians. The Second Edition is also an ideal textbook for upper-undergraduate and graduate-level courses in biostatistics and applied statistics. William F. Rosenberger, PhD, is University Professor and Chairman of the Department of Statistics at George Mason University. He is a Fellow of the American Statistical Association and the Institute of Mathematical Statistics, and author of over 80 refereed journal articles, as well as The Theory of Response-Adaptive Randomization in Clinical Trials, also published by Wiley. John M. Lachin, ScD, is Research Professor in the Department of Epidemiology and Biostatistics as well as in the Department of Statistics at The George Washington University. A Fellow of the American Statistical Association and the Society for Clinical Trials, Dr. Lachin is actively involved in coordinating center activities for clinical trials of diabetes. He is the author of Biostatistical Methods: The Assessment of Relative Risks, Second Edition, also published by Wiley.

Download or read book Validity and Inter Rater Reliability Testing of Quality Assessment Instruments written by U. S. Department of Health and Human Services and published by CreateSpace. This book was released on 2013-04-09 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: The internal validity of a study reflects the extent to which the design and conduct of the study have prevented bias(es). One of the key steps in a systematic review is assessment of a study's internal validity, or potential for bias. This assessment serves to: (1) identify the strengths and limitations of the included studies; (2) investigate, and potentially explain heterogeneity in findings across different studies included in a systematic review; and (3) grade the strength of evidence for a given question. The risk of bias assessment directly informs one of four key domains considered when assessing the strength of evidence. With the increase in the number of published systematic reviews and development of systematic review methodology over the past 15 years, close attention has been paid to the methods for assessing internal validity. Until recently this has been referred to as “quality assessment” or “assessment of methodological quality.” In this context “quality” refers to “the confidence that the trial design, conduct, and analysis has minimized or avoided biases in its treatment comparisons.” To facilitate the assessment of methodological quality, a plethora of tools has emerged. Some of these tools were developed for specific study designs (e.g., randomized controlled trials (RCTs), cohort studies, case-control studies), while others were intended to be applied to a range of designs. The tools often incorporate characteristics that may be associated with bias; however, many tools also contain elements related to reporting (e.g., was the study population described) and design (e.g., was a sample size calculation performed) that are not related to bias. The Cochrane Collaboration recently developed a tool to assess the potential risk of bias in RCTs. The Risk of Bias (ROB) tool was developed to address some of the shortcomings of existing quality assessment instruments, including over-reliance on reporting rather than methods. Several systematic reviews have catalogued and critiqued the numerous tools available to assess methodological quality, or risk of bias of primary studies. In summary, few existing tools have undergone extensive inter-rater reliability or validity testing. Moreover, the focus of much of the tool development or testing that has been done has been on criterion or face validity. Therefore it is unknown whether, or to what extent, the summary assessments based on these tools differentiate between studies with biased and unbiased results (i.e., studies that may over- or underestimate treatment effects). There is a clear need for inter-rater reliability testing of different tools in order to enhance consistency in their application and interpretation across different systematic reviews. Further, validity testing is essential to ensure that the tools being used can identify studies with biased results. Finally, there is a need to determine inter-rater reliability and validity in order to support the uptake and use of individual tools that are recommended by the systematic review community, and specifically the ROB tool within the Evidence-based Practice Center (EPC) Program. In this project we focused on two tools that are commonly used in systematic reviews. The Cochrane ROB tool was designed for RCTs and is the instrument recommended by The Cochrane Collaboration for use in systematic reviews of RCTs. The Newcastle-Ottawa Scale is commonly used for nonrandomized studies, specifically cohort and case-control studies.

Download or read book Implementing Randomized Field Trials in Education written by National Research Council and published by National Academies Press. This book was released on 2004-04-21 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The central idea of evidence-based education-that education policy and practice ought to be fashioned based on what is known from rigorous research-offers a compelling way to approach reform efforts. Recent federal trends reflect a growing enthusiasm for such change. Most visibly, the 2002 No Child Left Behind Act requires that "scientifically based [education] research" drive the use of federal education funds at the state and local levels. This emphasis is also reflected in a number of government and nongovernment initiatives across the country. As consensus builds around the goals of evidence-based education, consideration of what it will take to make it a reality becomes the crucial next step. In this context, the Center for Education of the National Research Council (NRC) has undertaken a series of activities to address issues related to the quality of scientific education research. In 2002, the NRC released Scientific Research in Education (National Research Council, 2002), a report designed to articulate the nature of scientific education research and to guide efforts aimed at improving its quality. Building on this work, the Committee on Research in Education was convened to advance an improved understanding of a scientific approach to addressing education problems; to engage the field of education research in action-oriented dialogue about how to further the accumulation of scientific knowledge; and to coordinate, support, and promote cross-fertilization among NRC efforts in education research. The main locus of activity undertaken to meet these objectives was a year-long series of workshops. This report is a summary of the third workshop in the series, on the implementation and implications of randomized field trials in education.

Download or read book Randomised Controlled Trials written by Alejandro R. Jadad and published by Wiley-Blackwell. This book was released on 1998 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: The contributors to this study present a balanced view of the strengths and weaknesses of randomised controlled trials in the medical setting. They cover all the essential issues without using statistics.

Download or read book Group Sequential Methods with Applications to Clinical Trials written by Christopher Jennison and published by CRC Press. This book was released on 1999-09-15 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Group sequential methods answer the needs of clinical trial monitoring committees who must assess the data available at an interim analysis. These interim results may provide grounds for terminating the study-effectively reducing costs-or may benefit the general patient population by allowing early dissemination of its findings. Group sequential methods provide a means to balance the ethical and financial advantages of stopping a study early against the risk of an incorrect conclusion. Group Sequential Methods with Applications to Clinical Trials describes group sequential stopping rules designed to reduce average study length and control Type I and II error probabilities. The authors present one-sided and two-sided tests, introduce several families of group sequential tests, and explain how to choose the most appropriate test and interim analysis schedule. Their topics include placebo-controlled randomized trials, bio-equivalence testing, crossover and longitudinal studies, and linear and generalized linear models. Research in group sequential analysis has progressed rapidly over the past 20 years. Group Sequential Methods with Applications to Clinical Trials surveys and extends current methods for planning and conducting interim analyses. It provides straightforward descriptions of group sequential hypothesis tests in a form suited for direct application to a wide variety of clinical trials. Medical statisticians engaged in any investigations planned with interim analyses will find this book a useful and important tool.