# Day-of-surgery cancellation

> A day-of-surgery cancellation is a planned operation called off on the day it was scheduled, usually after the patient has arrived fasted. Most are preventable: the common causes are unmanaged medications, unoptimised comorbidity, unscreened risk such as sleep apnoea, and logistical failures — all of which are identifiable weeks earlier.

*Source: https://getpathways.ai/glossary/day-of-surgery-cancellation*

Also known as: DOSC, same-day cancellation, late cancellation

- **Also called**: DOSC, late cancellation
- **Common causes**: Medication management, unoptimised comorbidity, unscreened risk, logistics
- **Typical cost**: Lost theatre time plus an unrecoverable slot
- **Prevention window**: From booking to roughly one week before surgery

## The four causes

**Medication management not planned.** The clearest case is the SGLT2 inhibitor
class, where a withholding plan must be made days ahead. When the medication
list comes from patient recall at a pre-op phone call, the drug is often
described as "something for sugar" and the plan is never made.

**Comorbidity not optimised.** Poor glycaemic control, uncontrolled hypertension
and anaemia are modifiable given a window. The window only exists if the problem
is found while there is still time.

**Risk not screened.** Undiagnosed obstructive sleep apnoea is the standing
example — it changes the anaesthetic plan and sometimes the location of care,
but only if the questions were asked.

**Logistics and consent.** Fasting instructions misunderstood, no escort home,
no discharge support. The cheapest to prevent and the most frustrating to lose a
theatre slot to.

## Why it is an information problem

In almost every case the fact that caused the cancellation existed weeks
earlier. It simply had not reached the anaesthetist while there was still time
to act on it. That is what makes cancellation rate responsive to when assessment
happens rather than to how carefully it is done — moving the assessment to
booking converts an unrecoverable cancellation into a manageable optimisation.