Cluster randomized trial (CRT) is one of the most common design for complex intervention. This paper mainly introduced:the definition of CRT, two designs of CRT including the completely randomization and the restricted randomization (such as stratified randomization and matching randomization), and the statistical analysis methods (such as the general statistical analysis and mixed effect model/multi-level model). This paper also introduced how to estimate the sample size of a CRT, how to report a CRT, and how to apply it into a clinical or community study.
This paper mainly introduces the design, advantages, disadvantages and its application of single case of randomized controlled trials (N-of-1 trials), and also introduces the commonly used data analysis methods of N-of-1 trials including nonparametric test and parameter test methods (t-test, paired t-test, analysis of variance), mixed-effects model, and meta-analysis. N-of-1 trials are suitable for individualized treatment, and could be expected to be widely used in the research of modern medicine and traditional Chinese medicine.
The CONSORT extension for reporting N-of-1 trials (CENT 2015) is designed to guide N-of-1 and series N-of-1 reporting. This study introduced the terminology (period, block or pair, sequence, washout period, and run-in period), the scope, the checklist and the diagram of CENT 2015 and demonstrated the complete guide frame for N-of-1, and thus to provide reference for relevant studies and improve the reporting quality of N-of-1 in China.