Common laboratory tests predict imminent death in ward patients

Objective: To estimate the ability of commonly measured laboratory variables to predict an imminent (within the same or next calendar day) death in ward patients. Design: Retrospective observational study. Setting: Two university affiliated hospitals. Patients: Cohort of 42,701 patients admitted for more than 24 hours and external validation cohort of 13,137 patients admitted for more than 24 hours. Intervention: We linked commonly measured laboratory tests with event databases and assessed the ability of each laboratory variable or combination of variables together with patient age to predict imminent death. Measurements and main results: In the inception teaching hospital, we studied 418,897 batches of tests in 42,701 patients (males 55 ; average age 65.8 ? 17.6 years), for a total of >2.5 million individual measurements. Among these patients, there were 1596 deaths. Multivariable logistic modelling achieved an AUC-ROC of 0.87 (95 CI: 0.85-0.89) for the prediction of imminent death. Using an additional 105,074 batches from a cohort of 13,137 patients from a second teaching hospital, the multivariate model achieved an AUC-ROC of 0.88 (95 CI: 0.85-0.90). Conclusions: Commonly performed laboratory tests can help predict imminent death in ward patients. Prospective investigations of the clinical utility of such predictions appear justified.