Design And Analysis Of Pragmatic Trials

Download Design And Analysis Of Pragmatic Trials full books in PDF, epub, and Kindle. Read online Design And Analysis Of Pragmatic Trials ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

Design and Analysis of Pragmatic Trials

Author : Song Zhang
Publisher : CRC Press
ISBN 13 : 1000873552
Total Pages : 215 pages
Book Rating : 4.0/5 (8 download)

DOWNLOAD NOW!

Book Synopsis Design and Analysis of Pragmatic Trials by : Song Zhang

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.

Bayesian Adaptive Methods for Clinical Trials

Author : Scott M. Berry
Publisher : CRC Press
ISBN 13 : 1439825513
Total Pages : 316 pages
Book Rating : 4.4/5 (398 download)

DOWNLOAD NOW!

Book Synopsis Bayesian Adaptive Methods for Clinical Trials by : Scott M. Berry

Download or read book Bayesian Adaptive Methods for Clinical Trials written by Scott M. Berry and published by CRC Press. This book was released on 2010-07-19 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Already popular in the analysis of medical device trials, adaptive Bayesian designs are increasingly being used in drug development for a wide variety of diseases and conditions, from Alzheimer's disease and multiple sclerosis to obesity, diabetes, hepatitis C, and HIV. Written by leading pioneers of Bayesian clinical trial designs, Bayesian Adapti

Small Clinical Trials

Author : Institute of Medicine
Publisher : National Academies Press
ISBN 13 : 0309171148
Total Pages : 221 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!

Book Synopsis Small Clinical Trials by : Institute of Medicine

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.

Design and Analysis of Group-randomized Trials

Author : David M. Murray
Publisher : Monographs in Epidemiology and
ISBN 13 : 0195120361
Total Pages : 481 pages
Book Rating : 4.1/5 (951 download)

DOWNLOAD NOW!

Book Synopsis Design and Analysis of Group-randomized Trials by : David M. Murray

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.

The Prevention and Treatment of Missing Data in Clinical Trials

Author : National Research Council
Publisher : National Academies Press
ISBN 13 : 030918651X
Total Pages : 163 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!

Book Synopsis The Prevention and Treatment of Missing Data in Clinical Trials by : National Research Council

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.

How to Design, Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research

Author : Michael J. Campbell
Publisher : John Wiley & Sons
ISBN 13 : 1119992028
Total Pages : 266 pages
Book Rating : 4.1/5 (199 download)

DOWNLOAD NOW!

Book Synopsis How to Design, Analyse and Report Cluster Randomised Trials in Medicine and Health Related Research by : Michael J. Campbell

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.

Best Care at Lower Cost

Author : Institute of Medicine
Publisher : National Academies Press
ISBN 13 : 0309282810
Total Pages : 437 pages
Book Rating : 4.3/5 (92 download)

DOWNLOAD NOW!

Book Synopsis Best Care at Lower Cost by : Institute of Medicine

Download or read book Best Care at Lower Cost written by Institute of Medicine and published by National Academies Press. This book was released on 2013-05-10 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: America's health care system has become too complex and costly to continue business as usual. Best Care at Lower Cost explains that inefficiencies, an overwhelming amount of data, and other economic and quality barriers hinder progress in improving health and threaten the nation's economic stability and global competitiveness. According to this report, the knowledge and tools exist to put the health system on the right course to achieve continuous improvement and better quality care at a lower cost. The costs of the system's current inefficiency underscore the urgent need for a systemwide transformation. About 30 percent of health spending in 2009-roughly $750 billion-was wasted on unnecessary services, excessive administrative costs, fraud, and other problems. Moreover, inefficiencies cause needless suffering. By one estimate, roughly 75,000 deaths might have been averted in 2005 if every state had delivered care at the quality level of the best performing state. This report states that the way health care providers currently train, practice, and learn new information cannot keep pace with the flood of research discoveries and technological advances. About 75 million Americans have more than one chronic condition, requiring coordination among multiple specialists and therapies, which can increase the potential for miscommunication, misdiagnosis, potentially conflicting interventions, and dangerous drug interactions. Best Care at Lower Cost emphasizes that a better use of data is a critical element of a continuously improving health system, such as mobile technologies and electronic health records that offer significant potential to capture and share health data better. In order for this to occur, the National Coordinator for Health Information Technology, IT developers, and standard-setting organizations should ensure that these systems are robust and interoperable. Clinicians and care organizations should fully adopt these technologies, and patients should be encouraged to use tools, such as personal health information portals, to actively engage in their care. This book is a call to action that will guide health care providers; administrators; caregivers; policy makers; health professionals; federal, state, and local government agencies; private and public health organizations; and educational institutions.

The Learning Healthcare System

Author : Institute of Medicine
Publisher : National Academies Press
ISBN 13 : 0309133939
Total Pages : 374 pages
Book Rating : 4.3/5 (91 download)

DOWNLOAD NOW!

Book Synopsis The Learning Healthcare System by : Institute of Medicine

Download or read book The Learning Healthcare System written by Institute of Medicine and published by National Academies Press. This book was released on 2007-06-01 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt: As our nation enters a new era of medical science that offers the real prospect of personalized health care, we will be confronted by an increasingly complex array of health care options and decisions. The Learning Healthcare System considers how health care is structured to develop and to apply evidence-from health profession training and infrastructure development to advances in research methodology, patient engagement, payment schemes, and measurement-and highlights opportunities for the creation of a sustainable learning health care system that gets the right care to people when they need it and then captures the results for improvement. This book will be of primary interest to hospital and insurance industry administrators, health care providers, those who train and educate health workers, researchers, and policymakers. The Learning Healthcare System is the first in a series that will focus on issues important to improving the development and application of evidence in health care decision making. The Roundtable on Evidence-Based Medicine serves as a neutral venue for cooperative work among key stakeholders on several dimensions: to help transform the availability and use of the best evidence for the collaborative health care choices of each patient and provider; to drive the process of discovery as a natural outgrowth of patient care; and, ultimately, to ensure innovation, quality, safety, and value in health care.

Encyclopedia of Research Design

Author : Neil J. Salkind
Publisher : SAGE
ISBN 13 : 1412961270
Total Pages : 1779 pages
Book Rating : 4.4/5 (129 download)

DOWNLOAD NOW!

Book Synopsis Encyclopedia of Research Design by : Neil J. Salkind

Download or read book Encyclopedia of Research Design written by Neil J. Salkind and published by SAGE. This book was released on 2010-06-22 with total page 1779 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Comprising more than 500 entries, the Encyclopedia of Research Design explains how to make decisions about research design, undertake research projects in an ethical manner, interpret and draw valid inferences from data, and evaluate experiment design strategies and results. Two additional features carry this encyclopedia far above other works in the field: bibliographic entries devoted to significant articles in the history of research design and reviews of contemporary tools, such as software and statistical procedures, used to analyze results. It covers the spectrum of research design strategies, from material presented in introductory classes to topics necessary in graduate research; it addresses cross- and multidisciplinary research needs, with many examples drawn from the social and behavioral sciences, neurosciences, and biomedical and life sciences; it provides summaries of advantages and disadvantages of often-used strategies; and it uses hundreds of sample tables, figures, and equations based on real-life cases."--Publisher's description.

Clinical Trials

Author : Duolao Wang
Publisher : Remedica
ISBN 13 : 1901346722
Total Pages : 497 pages
Book Rating : 4.9/5 (13 download)

DOWNLOAD NOW!

Book Synopsis Clinical Trials by : Duolao Wang

Download or read book Clinical Trials written by Duolao Wang and published by Remedica. This book was released on 2006 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explains statistics specifically for a medically literate audience. Readers gain not only an understanding of the basics of medical statistics, but also a critical insight into how to review and evaluate clinical trial evidence.

Field Trials of Health Interventions

Author : Peter G. Smith
Publisher :
ISBN 13 : 0198732864
Total Pages : 479 pages
Book Rating : 4.1/5 (987 download)

DOWNLOAD NOW!

Book Synopsis Field Trials of Health Interventions by : Peter G. Smith

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.

Registries for Evaluating Patient Outcomes

Author : Agency for Healthcare Research and Quality/AHRQ
Publisher : Government Printing Office
ISBN 13 : 1587634333
Total Pages : 385 pages
Book Rating : 4.5/5 (876 download)

DOWNLOAD NOW!

Book Synopsis Registries for Evaluating Patient Outcomes by : Agency for Healthcare Research and Quality/AHRQ

Download or read book Registries for Evaluating Patient Outcomes written by Agency for Healthcare Research and Quality/AHRQ and published by Government Printing Office. This book was released on 2014-04-01 with total page 385 pages. Available in PDF, EPUB and Kindle. Book excerpt: This User’s Guide is intended to support the design, implementation, analysis, interpretation, and quality evaluation of registries created to increase understanding of patient outcomes. For the purposes of this guide, a patient registry is an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure, and that serves one or more predetermined scientific, clinical, or policy purposes. A registry database is a file (or files) derived from the registry. Although registries can serve many purposes, this guide focuses on registries created for one or more of the following purposes: to describe the natural history of disease, to determine clinical effectiveness or cost-effectiveness of health care products and services, to measure or monitor safety and harm, and/or to measure quality of care. Registries are classified according to how their populations are defined. For example, product registries include patients who have been exposed to biopharmaceutical products or medical devices. Health services registries consist of patients who have had a common procedure, clinical encounter, or hospitalization. Disease or condition registries are defined by patients having the same diagnosis, such as cystic fibrosis or heart failure. The User’s Guide was created by researchers affiliated with AHRQ’s Effective Health Care Program, particularly those who participated in AHRQ’s DEcIDE (Developing Evidence to Inform Decisions About Effectiveness) program. Chapters were subject to multiple internal and external independent reviews.

Designing Randomised Trials in Health, Education and the Social Sciences

Author : D. Torgerson
Publisher : Springer
ISBN 13 : 0230583997
Total Pages : 226 pages
Book Rating : 4.2/5 (35 download)

DOWNLOAD NOW!

Book Synopsis Designing Randomised Trials in Health, Education and the Social Sciences by : D. Torgerson

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.

Clinical Epidemiology

Author : R. Brian Haynes
Publisher : Lippincott Williams & Wilkins
ISBN 13 : 1451178794
Total Pages : 516 pages
Book Rating : 4.4/5 (511 download)

DOWNLOAD NOW!

Book Synopsis Clinical Epidemiology by : R. Brian Haynes

Download or read book Clinical Epidemiology written by R. Brian Haynes and published by Lippincott Williams & Wilkins. This book was released on 2012-03-29 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Third Edition of this popular text focuses on clinical-practice research methods. It is written by clinicians with experience in generating and answering researchable questions about real-world clinical practice and health care—the prevention, treatment, diagnosis, prognosis, and causes of diseases, the measurement of quality of life, and the effects of innovations in health services. The book has a problem-oriented and protocol-based approach and is written at an introductory level, emphasizing key principles and their applications. A bound-in CD-ROM contains the full text of the book to help the reader locate needed information.

Developing a Protocol for Observational Comparative Effectiveness Research: A User's Guide

Author : Agency for Health Care Research and Quality (U.S.)
Publisher : Government Printing Office
ISBN 13 : 1587634236
Total Pages : 236 pages
Book Rating : 4.5/5 (876 download)

DOWNLOAD NOW!

Book Synopsis Developing a Protocol for Observational Comparative Effectiveness Research: A User's Guide by : Agency for Health Care Research and Quality (U.S.)

Download or read book Developing a Protocol for Observational Comparative Effectiveness Research: A User's Guide written by Agency for Health Care Research and Quality (U.S.) and published by Government Printing Office. This book was released on 2013-02-21 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This User’s Guide is a resource for investigators and stakeholders who develop and review observational comparative effectiveness research protocols. It explains how to (1) identify key considerations and best practices for research design; (2) build a protocol based on these standards and best practices; and (3) judge the adequacy and completeness of a protocol. Eleven chapters cover all aspects of research design, including: developing study objectives, defining and refining study questions, addressing the heterogeneity of treatment effect, characterizing exposure, selecting a comparator, defining and measuring outcomes, and identifying optimal data sources. Checklists of guidance and key considerations for protocols are provided at the end of each chapter. The User’s Guide was created by researchers affiliated with AHRQ’s Effective Health Care Program, particularly those who participated in AHRQ’s DEcIDE (Developing Evidence to Inform Decisions About Effectiveness) program. Chapters were subject to multiple internal and external independent reviews. More more information, please consult the Agency website: www.effectivehealthcare.ahrq.gov)

Patient-Reported Outcomes in Performance Measurement

Author : David Cella
Publisher : RTI Press
ISBN 13 : 193483114X
Total Pages : 97 pages
Book Rating : 4.9/5 (348 download)

DOWNLOAD NOW!

Book Synopsis Patient-Reported Outcomes in Performance Measurement by : David Cella

Download or read book Patient-Reported Outcomes in Performance Measurement written by David Cella and published by RTI Press. This book was released on 2015-09-17 with total page 97 pages. Available in PDF, EPUB and Kindle. Book excerpt: Patient-reported outcomes (PROs) are measures of how patients feel or what they are able to do in the context of their health status; PROs are reports, usually on questionnaires, about a patient's health conditions, health behaviors, or experiences with health care that individuals report directly, without modification of responses by clinicians or others; thus, they directly reflect the voice of the patient. PROs cover domains such as physical health, mental and emotional health, functioning, symptoms and symptom burden, and health behaviors. They are relevant for many activities: helping patients and their clinicians make informed decisions about health care, monitoring the progress of care, setting policies for coverage and reimbursement of health services, improving the quality of health care services, and tracking or reporting on the performance of health care delivery organizations. We address the major methodological issues related to choosing, administering, and using PROs for these purposes, particularly in clinical practice settings. We include a framework for best practices in selecting PROs, focusing on choosing appropriate methods and modes for administering PRO measures to accommodate patients with diverse linguistic, cultural, educational, and functional skills, understanding measures developed through both classic and modern test theory, and addressing complex issues relating to scoring and analyzing PRO data.

Clinical Trials in Psychiatry

Author : Brian S. Everitt
Publisher : John Wiley & Sons
ISBN 13 : 9780470723845
Total Pages : 248 pages
Book Rating : 4.7/5 (238 download)

DOWNLOAD NOW!

Book Synopsis Clinical Trials in Psychiatry by : Brian S. Everitt

Download or read book Clinical Trials in Psychiatry written by Brian S. Everitt and published by John Wiley & Sons. This book was released on 2008-04-15 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: At last – a new edition of the highly acclaimed book Clinical Trials in Psychiatry This book provides a concise but thorough overview of clinical trials in psychiatry, invaluable to those seeking solutions to numerous problems relating to design, methodology and analysis of such trials. Practical examples and applications are used to ground theory whenever possible. The Second Edition includes new information regarding: Recent important psychiatric trials More specific discussion of psychiatry in the USA and the particular problems of trials in the USA, including comments about the FDA (U.S. Food and Drug Administration) An extended chapter on meta-analysis Further discussion of sub-group analysis Special features include appendices outlining how to design and report clinical trials, what websites and software programs are appropriate and an extensive reference section. From the reviews of the First Edition: “Everitt & Wessely are to be congratulated on producing an excellent guide to help overcome the snags in clinical trial research. Clearly written and in an engrossing style, the book is likely to become a classic textbook on clinical trials, and not just in psychiatry. The authors’ enthusiasm and grasp of clinical trial research make for a gripping and insightful read...it is one of the very best books that has been written on clinical trials.” THE BRITISH JOURNAL OF PSYCHIATRY "The experience of both authors in this area gives the book a very pragmatic approach grounded in reality, with theoretical overviews invariably being followed by practical examples and applications... an invaluable companion to anyone involved in, or contemplating undertaking, clinical trials research.” PSYCHOLOGICAL MEDICINE