Use of an objective measure of time to recovery after cardiac surgery – the STET randomised controlled trial

Methods Post-operative hospital stay is a commonly used measure of recovery. However, in an open surgical trial, where the decision to discharge the patient from hospital lies with the surgeon, post operative hospital stay is susceptible to bias. For the STET trial we developed an objective measure of recovery. Recovery time was defined as the time from surgery until the patient was considered fit for discharge. Patients were classified fit (a) when the x-ray was clear (no evidence of pleural effusion requiring drainage, lung collapse/consolidation, pneumothorax); (b) there was no suspected systemic, lower respiratory tract or wound infection; (c) routine blood results and temperature were normal and (d) when physically mobile (walking 70m, bowels open and oxygen saturation>95%). These recovery criteria were monitored daily until discharge.