Abstract: Investigates the effects of participation in the Intensive Care Unit Randomised Trial Comparing Two Approaches to Oxygen therapy (ICU-ROX) randomised controlled trial, on attitudes and practices in relation to ICU oxygen therapy. Distributes a practitioner attitudes survey to 112 specialist doctors and 153 ICU nurses. Performs both inception and retrospective cohort studies using the Australian and NZ ICU adult patient database before, and post-publication of the ICU-ROX trial results.