Frailty Screening Using the Risk Analysis Index: A User Guide.

The Risk Analysis Index (RAI) has emerged as the most thoroughly validated and flexible assessment of surgical frailty, proven feasible for at-scale bedside screening and available in a suite of tools, that effectively risk stratifies patients across a wide variety of clinical contexts and data sources. This user guide provides a definitive summary of the RAI's theoretical model, historical development, validation, statistical performance, and clinical interpretation, placing the RAI in context with other frailty assessments and emphasizing some of its advantages. Detailed instructions are provided for each RAI variant, along with a systematic review of existing RAI-related literature.