Reporting of Sample Size Parameters in Randomized Controlled Trials Published in Prosthodontic Journals

Area of Science:

• Dental Research
• Clinical Trials Methodology

Background:

• Proper sample size determination is crucial for the validity and feasibility of randomized controlled trials (RCTs).
• Inadequate sample sizes can lead to underpowered studies, while overly large samples may be impractical.

Purpose of the Study:

• To assess the reporting quality of sample size methodology and parameters in prosthodontic RCTs.
• To identify common practices and deficiencies in sample size reporting within this specialty.

Main Methods:

• A systematic search of MEDLINE identified RCTs published in The Journal of Prosthodontics and The Journal of Prosthetic Dentistry (2008-2017).
• Abstract and methodology sections were reviewed for reporting of sample size calculation methods and key parameters: type I error (α), type II error (β)/power, minimal clinically relevant difference (MCRD), and variability.

Main Results:

• Of 42 included RCTs, only 50% reported the sample size determination method, and a mere 17% reported all four key parameters.
• Type I error (α) was reported in 90% of studies, power in 38%, MCRD in 26%, and variability in only 12%.

Conclusions:

• Reporting of sample size methodology and parameters in prosthodontic RCTs is insufficient.
• This lack of comprehensive reporting may compromise the reliability and interpretability of findings in dental research.