Evidence-based medicine versus network analysis. Number of participants of a clinical study versus the number of variables measured for each individual. In classical evidence-based medicine, many cases and controls are studied for a small number of variables (top left), whereas network analysis, can build upon fewer patients, for which many variables are measured longitudinally (bottom right). The latter benefits from using mechanistic modelling for analyzing data, while evidence-based medicine largely relies on statistical modelling. Big data systems medicine (top right) fuses both approaches by integrating large number of data points derived from several patients into predictive mechanistic models.