Table1.

Observation period and intervention method for each group

	Group A	Group B	Group C
observation period	11–30 September 2013	24 March–18 April 2014	22 June–11 July 2020
Educator to patients	none	Anesthesiologist	multidisciplinary intervention
Date of education	none	Mostly the day before surgery	Mostly 2 weeks before surgery
Date of fasting instruction	the day before surgery	the day before surgery	perioperative management center
Description	oral	Document and oral	Document and oral