Cluster Randomized Controlled Trials: A Quick Update on Concepts and Types

Cluster randomized controlled trials have certain complexities both at design and statistical analysis stages of the experiment. Although, this experimental study approach offers solutions in situations where it would be inappropriate to randomize individuals into treatment arms its design and statistical analysis are not without certain unique challenges. Compared to individual randomized controlled trials, very limited understanding of the design concepts in cluster randomized controlled trials exists, this perhaps explain reasons it is not as popular as the former. This short note presents a quick description of cluster randomized controlled trials with a view to enhance capacity in its design, conduct and management. It will also provide students and researchers with ready-made information necessary to make appropriate choices regarding type of cluster randomized trials given a prevailing research environment.