Sample size calculations in randomised trials: mandatory and mystical

Area of Science:

• Clinical Trials Methodology
• Biostatistics
• Research Ethics

Background:

• Sample size calculations are a standard prerequisite for randomized trials, influencing their perceived ethical standing.
• The determination of effect size in these calculations involves subjective clinical judgments, which significantly impact the required sample size.
• Current practices often lead to trials being labeled unethical based on perceived imprecision in sample size determination.

Purpose of the Study:

• To question the ethical implications of labeling randomized trials as unethical due to imprecise sample size calculations.
• To advocate for a shift in focus from sample size fixation to the importance of methodological quality in research.
• To emphasize the value of unbiased trials, even with imprecise results, over no results.

Main Methods:

• The study critically examines the process and implications of a-priori sample size calculations in randomized trials.
• It analyzes the impact of subjective clinical judgments on effect size determination and its subsequent effect on sample size.
• The authors propose alternative perspectives on evaluating the ethical standing and value of research studies.

Main Results:

• Imprecise sample size calculations should not automatically render a trial unethical.
• Underpowered trials can be ethically acceptable and scientifically valuable if they employ rigorous methodology to minimize bias.
• Prioritizing methodological rigor and transparent reporting is more beneficial than fixating on precise sample sizes.

Conclusions:

• A greater emphasis on methodological quality and bias elimination in randomized trials is recommended.
• Unbiased trial results, even if imprecise, are preferable to the absence of data.
• Clinicians and patients benefit from reliable, unbiased research findings regardless of exact sample size precision.