ABSTRACT
A cluster randomized trial is de ned as a trial in which “intact social units, or clusters of individuals, rather than individuals themselves, are randomized” [1]. Such a design is well adapted to assess organizational and behavioral interventions implemented at the level of health organizational units or geographical areas [2], as well as interventions that apply at the patient level such as therapeutic education programs [3], interventions aimed at curing or preventing transmission of contagious diseases [4], or global care plans [5]. The cluster randomized trial, also named “real-world trial” [6], is now considered a well-adapted design for pragmatic trials [7] as “a way to allow for real-world practice within study centers while addressing intercenter bias by randomizing those to the study interventions.” The use of such
CONTENTS
8.1 Introduction .................................................................................................. 93 8.2 Why Randomize Clusters? ......................................................................... 94 8.3 Which Randomization Unit? ...................................................................... 95 8.4 Which Type of Intervention? ...................................................................... 96 8.5 Which Type of Consent? Which Information? ........................................ 96 8.6 Which Statistical Speci cities? ................................................................... 97 8.7 What Are the Limits to Cluster Randomization? .................................... 98 8.8 Conclusion ....................................................................................................99 References ...............................................................................................................99
