Reporting Sample Size Calculation in Randomized Clinical Trials Published in 4 Orthodontic Journals

Area of Science:

• Orthodontics
• Clinical Research Methodology

Background:

• Sample size calculations are crucial for the validity and reliability of randomized clinical trials (RCTs).
• Inadequate reporting of sample size parameters can compromise the interpretability of research findings.

Purpose of the Study:

• To assess the reporting quality of sample size calculations in orthodontic randomized clinical trials.
• To identify common deficiencies in the description of sample size calculation parameters.

Main Methods:

• A cross-sectional study analyzed 142 RCTs published between 2015-2019 in top-tier orthodontic journals.
• Two experienced orthodontists evaluated the reporting of sample size calculations and their key components: significance level, power, effect size, and variability.

Main Results:

• 120 (84.5%) RCTs reported sample size calculations, but only 70 (58.3%) fully detailed all necessary parameters.
• Common omissions included reporting of confidence level, test power, effect size, and expected variability, with varying frequencies across journals.

Conclusions:

• Randomized clinical trials in leading orthodontic journals often lack comprehensive reporting of sample size calculation parameters.
• There is a need to enhance the transparency and completeness of sample size reporting in orthodontic research to ensure methodological rigor.