6.2 Clinical variables The initial strategy was to select clinical variables through a systematic review of the literature in combination with expert advice. The review was started, but yielded over 8000 abstracts, and over 1000 included full texts, and was therefore considered too large for the scope of this project. However, an overview of the clinical variables assessed in these papers was made, and will be taken into account during the variable selection process. Clinical variables will be selected based on literature in combination with expert advice. Exclusion of a variable will be considered when the variable is not not consistently documented in medical records, when few studies concerning this variable have been published, when multiple published studies show a weak association with bleeding, when a strong interaction with another variable is expected (e.g. birth weight and IUGR), or when the variable is difficult to measure regularly (e.g. blood parameters that need large blood samples).