• emergency service;
  • hospital;
  • intensive care unit;
  • length of stay;
  • mortality;
  • time factor


Objectives: To determine if an association exists between the time of day when a patient presents to ED and their outcome for those admitted directly to the ICU.

Methods: We performed a retrospective cohort study on all patients admitted to the ICU directly from the ED from 1 July 2006 to 30 June 2008, using data from the ED and ICU databases in a single institution. Comparisons of mortality, length of stay in the ED, ICU, hospital and time on a ventilator were made based on the time of presentation.

Results: A total of 400 patients were admitted to ICU from the ED. There was no evidence of a difference in mortality between those presenting between midnight and 8 am, 8 am and 4 pm or 4 pm and midnight (23.2%, 22.8%, 19.5%, respectively, P= 0.71), or for those presenting during office hours (8 am–4 pm Monday to Friday) or outside office hours (26.1% and 20.2%, respectively, P= 0.23). There were no differences in time on a ventilator, or length of stay in ED, intensive care and hospital.

Conclusions: The time of day patients arrive at the ED has no association with length of stay in ED, intensive care or hospital, time on the ventilator, or mortality for those who are admitted to the ICU.