**Objective:** The objective is to develop a guideline for a statistical analysis plan for observational studies that accounts for initial data analysis and records deviations from initial plans (SAPI).
**Scope** of the statistical analysis plans: Observational studies using low dimensional regression type models
**Importance:** There is an absence of guidance on incorporating a systematic process for initial data analysis in statistical analysis plans or study protocol guidelines. Initial data analysis is often performed, but it may not have been planned or conducted systematically. Revisions of SAPs are often necessary due to unforeseen issues with the data. Such changes should be documented with a rationale in an amended SAP. This protects against ad hoc decisions during analysis, non-transparency, and irreproducibility, even when an SAP was present.
This project is being conducted by a committee of members of the **STRATOS Initiative** (Gary Collins, Georg Heinze, Marianne Huebner, Lara Lusa, Willi Sauerbrei, Carsten Schmidt). All STRATOS members are invited to participate in a Delphi process to develop a SAPI checklist. Members representing different topic groups in the STRATOS Initiative comprise the Delphi consensus panel.