This project proposes to measure delay to admission to Intensive Care (ICU) using both organisational and pathophysiological timing. Delays in the United Kingdom NHS are widely reported {McQuillan:1998p127, Hillman:2001p90} possibly because there are fewer ICU beds than in many other developed health care systems.{Wunsch:2008p121} We intend to measure the chronological time between the moment when a patient is 'referred and assessed as requiring Critical Care', and their actual time of admission. We will determine how often delays occur, and whether they affect outcome. Requirements for critical care are not, however, absolute. Importantly, the assessment of a prospective patient is not made in isolation. If ICU beds are already fully occupied, then decision makers must organise a transfer to another unit (with risks to the patient), organise a premature discharge of another patient, or defer admission. We will also therefore consider such deferments alongside delays, and their impact on survival.