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Cluster randomized clinical trials in orthodontics: design, analysis and reporting issues
Nikolaos Pandis1, Tanya Walsh, Argy Polychronopoulou
1Private Practice, Corfu, Greece.
European Journal of Orthodontics
|October 9, 2012
Summary
Cluster randomized trials (CRTs) use clusters for randomization, requiring specific methods for sample size and analysis. Ignoring these cluster-specific procedures in dental research can lead to inaccurate results.
Area of Science:
- Dental research methodology
- Clinical trial design
Background:
- Cluster randomized trials (CRTs) employ clusters (e.g., dental practices, patients with multiple teeth) as the unit of randomization.
- CRTs necessitate distinct methodological approaches for sample size calculation, randomization, data analysis, and reporting.
Purpose of the Study:
- To highlight the methodological characteristics of cluster randomized designs in orthodontics.
- To explain potential issues arising from treating clustered observations as independent in dental research.
Main Methods:
- Review of methodological considerations for cluster randomized trials.
- Illustrative examples applied to orthodontic research settings.
Main Results:
- Clustered designs require larger sample sizes due to intra-cluster correlation.
- Specialized statistical analyses are essential to account for correlated observations within clusters.
Conclusions:
- Adherence to CRT methodological procedures is crucial in dental research publications.
- Incorrect analysis of clustered data as independent can yield erroneous findings, particularly in orthodontics.
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