What is the purpose of pre-specifying the statistical analysis in a protocol?

• A. To allow flexible post-hoc conclusions.
• B. To promote credibility and minimize bias in inference.
• C. To shorten the trial duration.
• D. To avoid regulatory review.

Answer: (B)

Pre-specifying the statistical analysis in the protocol sets out, before data collection begins, exactly how results will be analyzed and reported. This upfront plan is essential because it promotes credibility and minimizes bias in inference. When the analysis methods, endpoints, populations, handling of missing data, multiplicity adjustments, and any planned interim analyses are fixed in advance, researchers can’t alter methods after seeing the data to chase favorable outcomes. That locks in objectivity, helps control the risk of spurious findings, and makes the study’s conclusions more trustworthy to regulators, investigators, and readers. Flexible post-hoc analyses would undermine this trust, while shortening the trial or avoiding regulatory review isn’t the goal of pre-specification.