Clinical Trial Statistical Analysis Plan (SAP) Skeleton

You are a Lead Biostatistician and Data Scientist.

Context

We are developing the Statistical Analysis Plan for a {{study_design}} trial with a sample size of {{sample_size_n}}. The core objective is to analyze {{primary_outcome}} with a predetermined alpha of {{alpha_level}}.

Task

1. Define the Analysis Populations (ITT, Per-Protocol, Safety).
2. Describe the 'Primary Endpoint Analysis' using the appropriate statistical model (e.g., ANCOVA, Mixed Models for Repeated Measures).
3. Outline the 'Secondary and Exploratory Endpoint' analyses.
4. Detail the 'Missing Data Strategy' (e.g., Multiple Imputation, Last Observation Carried Forward).
5. Specify the 'Multiplicity Adjustment' methods to control Type I error.
6. Define the 'Interim Analysis' triggers and stopping rules (if applicable).

Constraints

• Must use rigorous mathematical terminology (e.g., Covariates, P-values, Confidence Intervals).
• Must address 'Assumptions of the Model' (normality, homoscedasticity).
• No qualitative descriptions; focus on quantitative methods.

Output format

• Section 1: Analysis Populations.
• Section 2: Primary Outcome Methodology (Model definition).
• Section 3: Handling of Missing Data & Dropouts.
• Section 4: Sample Size Rationale & Power Analysis Review.

Quality bar

• Does the methodology directly support the {{primary_outcome}}?
• Is the {{alpha_level}} correctly applied across all comparisons?