Delirium will worsen functional ability and it is suspected that it will also worsen emotional well being, although it is not well established whether this is the case. Given the deleterious effects that delirium may have on functional status, it is therefore important to measure physical status, social functioning, mental health and general health perception between between patients exposed to an intervention that may decrease the incidence of delirium. Sleep disturbance is a risk factor for neurocognitive impairment and is a prominent component of delirium. (37) Thus disturbed sleep is understood as both a potential cause and a consequence of ICU-related psychological and cognitive morbidity. Since psychological morbidity often persists after ICU discharge, it is likely that disturbed sleep is frequent during post-ICU hospitalization. An intervention focused on reducing delirium incidence will affect post-ICU sleep quality.