Table 1.

Variables to be collected for the study

Type	Variable	Form	Source	Time	Standardised tool?
Explanatory	Postoperative delirium incidence	Dichotomous (present or absent)	ENGAGES postoperative assessment	Inpatient postoperative hospital days	Yes
	Postoperative delirium duration	Categorical (<3 days or ≥3 days)	ENGAGES postoperative assessment	Inpatient postoperative hospital days	NA
	Charlson Comorbidity Index	0, 1, 2, 3+	Medical record	Baseline	Yes
	Grip strength	Continuous	Research team member	Baseline and 1 year	Yes
	Timed Up and Go	Continuous	Research team member	Baseline and 1 year	Yes
	History of falls	Dichotomous	Survey	Baseline	NA
	Postoperative complications	0, 1, 2, 3+	Survey and medical record	1 year	No
	ASA physical status	Ordinal, 1–6	Anaesthesia record	Baseline	Yes
Outcome	Trails A	Continuous	Research team member	Baseline and 1 year	Yes
	Trails B	Continuous	Research team member	Baseline and 1 year	Yes
	Stroop Color and Word Test	Continuous	Research team member	Baseline and 1 year	Yes
	Physical quality of life	Continuous	Survey	Baseline and 1 year	Yes
	Mental quality of life	Continuous	Survey	Baseline and 1 year	Yes
	Dementia	Dichotomous	Survey	Baseline and 1 year	Yes
Confounder	Age	Continuous	Medical record	Baseline	NA
	Sex	Dichotomous	Medical record	Baseline	NA
	Education level	<High school, high school, >high school	Research team member	Baseline	NA
	Functional dependence	Ordinal, 0–100	Research team member	Baseline and 1 year	Yes
	Smoking status	Current, past, never	CPAP assessment	Baseline	NA
	Depression	Dichotomous	Medical record and survey	Baseline and 1 year	Yes
	Preoperative vascular disease	Dichotomous	Medical record	Baseline	No
	Type of surgery	10 Categories	CPAP assessment	Baseline	NA
	ENGAGES randomisation	Dichotomous	Research team member	Day of surgery	NA

ASA, American Society of Anesthesiologists; CPAP, Center for Preoperative Assessment and Planning; ENGAGES, Electroencephalography Guidance of Anaesthesia to Alleviate Geriatric syndromes; NA, not applicable.