Complexity of nursing care at 24 h from admission predicts in-hospital mortality in medical units: a cohort study.

Background: The Informative System of Nursing Performance was developed to measure complexity of nursing care based on the actual interventions performed by nurses at the point of care. The association of this score with in-hospital mortality was not investigated before. Having this information is relevant to define evidence-based criteria that hospital administrators can use to allocate nursing workforce according to the real and current patients' need for nursing care.