A Statistical Analysis Plan Template for Observational Studies: Promoting Quality and Rigor in Research.

Rigorous and transparent research practices are essential for trustworthy scientific findings, particularly in observational studies where data-driven analyses carry risks of questionable research practices. This paper introduces a statistical analysis plan (SAP) template specifically designed for observational research, an area where guidance on SAP development is crucially lacking. The template offers clear guidelines for prespecifying key aspects of the analysis. The guidance encompasses essential SAP components, including study objectives, measures and variables, and analytical methods, as well as administrative details to support documentation and reproducibility. Designed for broad useability, the template is intended to support researchers, statisticians, students, and interdisciplinary teams across clinical, academic, industry, and government sectors. By adopting this template, researchers can strengthen study integrity, reduce ad hoc analytic modifications, demonstrate the avoidance of questionable research practices such as p-hacking, and contribute to robust and reliable findings in observational research.