A Statistical Analysis Plan (SAP) is a prespecified document that describes how clinical trial data will be analyzed to address study objectives and endpoints.
SAPs define analysis populations, statistical methods, handling of missing data, multiplicity adjustments, interim analyses, and rules for subgroup evaluations. By specifying methods before unblinding, SAPs reduce bias and support credible interpretation of trial results. SAP alignment with the protocol and data standards improves consistency from data collection through reporting and regulatory submission. A well-written SAP strengthens transparency, reproducibility, and regulatory confidence in study conclusions.