Perform a UK wide multi-centre prospective observational study of frailty measurement in the critically ill utilising current ICNARC and Scottish Intersive Care Society Audit Group data capture.

Perform a UK-wide multi-centre prospective observational study of frailty measurement in the critically ill utilising current Intensive Care National Audit & Research Centre (ICNARC) and Scottish Intersive Care Society Audit Group (SICSAG) data capture, supplemented by longer term measurement of physical and mental function and quality of life.