We have completed an extensive programme of work to inform this study. Based on this data we have identified a patient population in whom an RCT will address many areas of clinical uncertainty. We will study longer-term ICU patients (higher illness severity; higher morbidity; worse long-term functional status; low long-term HRQoL; greater illness costs) who are aged ≥55 (high incidence of IHD; less certainty regarding safety with restrictive approach in TRICC trial). The treatment exposure will last longer than the TRICC trial, potentially including post-ICU care, because anaemia recovers slowly.