Can we predict when an operating list will finish?

Mean anaesthetic, surgical and turnover times were used to predict finishing times for elective general surgical operating lists. A predicted early finish was correct in 70 per cent, a predicted on-time finish in 19 per cent, and a predicted late finish in 56 per cent. Overall, predictions of an early or late finish had a low sensitivity (62 per cent and 65 per cent) and high false positive rate (30 per cent and 44 per cent). Over-runs, caused by too many cases, and early finishes, owing to insufficient cases were reliably predicted. It is suggested that mean procedure times can be used to identify under or over utilisation caused by under or over-booking but indiscriminate use will not improve list utilisation.