# Theatre utilisation

> Theatre utilisation measures how much of the operating time allocated to a list is actually used for surgery. It is a core efficiency measure for both public and private services. Late cancellations damage it disproportionately, because a slot lost on the day usually cannot be refilled — unlike one released with a week's notice.

*Source: https://getpathways.ai/glossary/theatre-utilisation*

Also known as: theatre efficiency, list utilisation, operating room 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.