Introduction: Quality assessment of included studies is a crucial step in any systematic review. Review and synthesis of prediction modelling studies is a relatively new and evolving area. The QUIPS (Quality in Prognostic Studies) tool is available for prognostic factor studies. However, a tool facilitating quality assessment for prediction modelling studies, both for diagnostic and prognostic prediction models, is needed. We have developed PROBAST, a tool for assessing the risk of bias and applicability of all types of prediction modelling studies. PROBAST assesses risk of bias and applicability of prediction modelling studies. It consists of five domains (participant selection, outcome, predictors, sample size and flow, analysis) and 23 signalling questions across these domains.

Objective: To provide an overview of PROBAST for prediction modelling studies, allowing participants an opportunity to apply the tool.

Description:
1. The first session will give an overview of the development and structure of PROBAST. We have used a Delphi process, including 42 experts in the field of prediction research. The presentation will give an overview of the process of development, the final version of the tool (including the domains covered and signalling questions) and guidance on how to use it.
2.In the second half of the workshop, participants will have the opportunity to experience this new tool first hand and to discuss issues with the developers of PROBAST.