The sample size estimated for this study was 6,000 patients. This sample size was based on the number of available general ICU beds 11 multiplied by 7 as an estimate of bed occupancy per month.
It was expected that 20-30% of the admitted patients would die on the ICU during the study period 12. This sample also included patients that had been re-admitted to the ICU for Level 3 care within the one month study period.