Theatre utilisation

Measures

Proportion of allocated operating time used for surgery

Damaged by

Late cancellations, late starts, overruns, gaps between cases

Why late cancellations hurt most

A slot lost on the day usually cannot be refilled

Recoverable when

The cancellation happens early enough to backfill from the waiting list

Not all lost time is equal

A cancellation a week out and a cancellation on the morning of surgery register as the same clinical event and are entirely different operationally. The first releases a slot that can be offered to someone on the waiting list. The second leaves a gap that will not be filled, because no suitable patient can be prepared, consented and fasted at that notice.

This is why utilisation is more sensitive to when problems are found than to how many there are. A service that identifies the same number of unfit patients earlier loses far less theatre time.

What it means for the assessment question

The operational case for screening at booking is really a utilisation argument rather than a clinical one — the clinical case for assessing patients properly was never in dispute.

Moving assessment to the point of booking converts a category of unrecoverable cancellation into a category of manageable rescheduling. The patient still may not be fit to proceed on the original date, but the list does not lose the hour, and the patient gets an optimisation window rather than a wasted fasting day.

For private services this maps directly onto revenue, which is why the arithmetic that usually decides a purchase is cancellation cost rather than per-patient cost.