Why is survival to 30 days after surgery used as the main survival measure?

Two very common measures used for looking at a hospital’s outcomes are “survival at discharge from hospital” and “30 day survival” after an operation. Survival at discharge is often used in other contexts as it’s the easiest to obtain – it is included within standard hospital records. However, survival to discharge does depend on the discharge procedures at that hospital. For instance, some hospitals will transfer very sick patients to other, more specialised hospitals, meaning that more patients will be alive at discharge from that hospital than the specialised hospital. Some hospitals might have close links with local palliative care services and so might discharge patients to these services if further treatment is considered unavailing. Again, such hospitals with have more patients alive at discharge compared to a hospital that look after the sickest patients until they die.

Therefore, if it is available, “30 day survival” after surgery is considered a more objective and preferable statistic than “survival to hospital discharge”, since it does not depend on the hospital’s discharge procedures.

While longer term survival is extremely important, 30-day survival post surgery was initially chosen as it is more straightforward to link this outcome to a child’s surgery and post-operative care than a longer range survival period which might, for instance, incorporate further treatment at different hospitals. The other important aspect of monitoring 30-day survival, particularly within hospitals, is that any worrying outcomes can be investigated very quickly since the survival outcomes are available (locally) within 30 days of a child’s operation.