A practical guide to cluster randomised trials inhealth services research

Cluster randomisedtrials 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 techniquesexplained.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 andreporting of cluster randomised trials. Those with a more general interest will find the plentiful examples illuminating. INDICE: Preface xiiiNotation xvTable of cases: Trials used as examples in more than one chapter in the book xviii1 Introduction 11.1 Introduction to randomised trials 21.2 Explanatory or pragmatic trials 21.3 How does a cluster randomised trial differ from other trials? 31.4 Between-cluster variability 91.5Why carry out cluster randomised trials? 101.6 Quality of evidence from cluster randomised trials 131.7 Historical perspectives 161.8 Summary 18References 192 Recruitment and ethics 222.1 Selecting clusters and participants to enhance external validity 222.2 Ethics of cluster randomised trials 242.3 Selection and recruitment of participants to enhance internal validity 352.4 Retention of participants in the trial 412.5 Summary 41References 413 Designing interventions 443.1 Lack of effectiveness of interventions evaluated in cluster randomised trials 453.2 What is a complex intervention? 463.3 Phases in the development of a complex intervention 503.4 Identifying evidence for potential intervention effect (pre-clinical phase) 503.5 Understanding more about intervention components (modelling phase) 533.6 Developing the optimum intervention and study design (exploratory trial phase) 553.7 What is the intervention? 573.8 Summary 58References 584 Pilot and feasibility studies 604.1 What is a pilot study?604.2 Reasons for conducting pilot and feasibility studies 634.3 Designing a pilot or feasibility study 694.4 Reporting and interpreting pilot studies 714.5 Summary 72References 735 Design 745.1 Parallel designs with only two arms 755.2 Cohort versus cross-sectional designs 855.3 Parallel designs with more than two arms 885.4 Crossover designs 925.5 Further design considerations 955.6 Summary 96References 966 Analysis 996.1 Data collection and management 996.2 Analysis - an introduction 1016.3 Analyses for two-arm, completely randomised, stratified or minimised designs 1046.4 Analyses for other designs 1246.5 Intention to treat and missing values 1296.6 Analysis planning 1316.7 Summary 132References 1337 Sample size calculations 1377.1 Factors affecting sample size forcluster randomised designs 1387.2 Calculating sample size using the intra-cluster correlation coeffi cient 1427.3 Sample size calculations for rates 1457.4Restricted number of clusters 1467.5 Trials with a small number of clusters 1497.6 Variability in cluster size 1507.7 Comparison of different measures of between-cluster variability 1547.8 Matched and stratifi ed designs 1607.9 Sample size for other designs 1667.10 Summary 169References 1698 The intra-cluster correlation coeffi cient 1728.1 What is the ICC? 1738.2 Sources of ICC estimates 1758.3 Choosing the ICC for use in sample size calculations 1798.4 Calculating ICC values 1858.5 Uncertainty in ICCs 1928.6 Summary 193References 1939 Other topics 196Richard Grieve9.1 Systematic reviews 1979.2 Cost effectiveness analyses 2079.3 Process evaluation 2129.4 Monitoring 2139.5 Summary 215References 21510 Trial reporting 21810.1 Trial quality and reporting quality 21810.2 Steps to improve trial reporting in the early stages of the trial 22710.3 Reporting randomised trials in journal and conference abstracts 23010.4 Applicationof CONSORT statement to cluster randomised trials 23210.5 Summary 262References 263Index 267

• ISBN: 978-1-119-96624-1
• Editorial: John Wiley & Sons
• Encuadernacion: Rústica
• Páginas: 272
• Fecha Publicación: 15/03/2012
• Nº Volúmenes: 1
• Idioma: Inglés