Data synthesis

The sample size used in each study was recorded when available and estimated for evaluation purposes when not available. If several models were used to train the algorithm on the same data set, the model with the highest AUC was selected.

Limited statistical power may lead to insufficient power to detect a significant association, resulting in unstable models. To overcome this problem, we calculated the events per variable (EPV) for traditional models. EPV was defined as the number of events divided by the number of predictor variables included in the multivariable model. An EPV value <10 suggests limited statistical power. ¹³ Because it was not possible to record and name the variables used in the deep learning models, ¹¹ the EPV could not be calculated.