**4.1 Epic deterioration index (EDI)**

The epic deterioration index (EDI) is a proprietary prediction model implemented in over 100 U.S. hospitals to support clinical-decision support in diagnosis of sepsis [24]. The EDI aims to detect patients who are deteriorate and require higher levels of care. Its score ranges from 0 to 100, in which the higher numbers denote a greater risk of experiencing a composite adverse outcome of requiring rapid response, resuscitation, ICU-level care, or death in the next 12–38 hours. The EDI uses a cumulative link model, a specific type of ordinal logistic regression model, that uses two parallel linear combinations of clinical inputs drawing two decision boundaries in the space of prediction using proportional odds assumptions. The details of the implementation are proprietary, and Epic has not shared this information publicly or described it in their published literature, but the accuracy of this model is 47.4% [24].
