The impact of late-starts and overruns on theatre utilisation rates.

The NHS Management Executive recommends that hospitals should aim to use 90% of planned theatre time and that theatre utilisation should be used as a key performance indicator. This study aims to investigate the impact of late-starts and overruns on theatre utilisation rates. Data were retrieved from a prospectively updated theatre database for all elective plastic surgical main theatre operating sessions carried out over a one year period. Theatre list utilisation was calculated as the percentage of the total allocated session time that was used for anaesthesia and operating. A total of 2,944 elective main theatre operations were performed in one year. Total theatre utilisation was 90.9%. Utilisation of lists starting less than one hour after the scheduled start time was similar to the utilisation of sessions starting more than one hour late (90.1% versus 91.7% respectively, p = 0.527). In contrast, overrunning lists demonstrated much higher utilisation rates than those that finished before the end of the session (96.7% versus 76.6% respectively, p < 0.001). The study shows that late-starts and overruns represent obvious sources of theatre inefficiency yet their impact on utilisation is misleading: overruns exaggerate theatre usage and late-starts have little impact upon it. We conclude that the use of utilisation as a marker of theatre performance requires caution.