Table 2.

Clinical impact: description of cohort and medication administration. “Differential RR” is the relative risk of receiving a medication in the high-delirium-risk group after AWOL-S implementation, after controlling for secular trends using rates of medication use in the low-risk group.

		Baseline		AWOL-S		p
		Low risk	High risk	Low risk	High risk	Before vs after AWOL-S
Number of surgical encounters		7,368	2,049	13,704	3,630
Age (years)		53 ± 16	67 ± 12	53 ± 16	68 ± 12	0.85
Unable to spell WORLD backward		10%	35%	13%	38%	<0.001
Not oriented to place		2.5%	15%	1.7%	13%	<0.001
High illness severity	(ASA 3+)	29%	77%	29%	76%	0.12
Surgery-specific delirium risk	Low	74%	7.4%	74%	7.1%	0.32
	Moderate	23%	70%	23%	70%
	High	2.6%	23%	3.0%	23%
Delirium in first 7 postop days		1.3%	10%	1.3%	11.4%	0.31
Perioperative medication use						Differential RR	p
Any benzodiazepine		54%	37%	50%	33%	0.95 [0.88–1.03]	0.24
Midazolam		54%	36%	50%	32%	0.95 [0.87–1.03]	0.19
Lorazepam		1.8%	2.0%	1.7%	1.8%	0.98 [0.63–1.53]	0.63
Any anticholinergic		12%	8.6%	12%	6.5%	0.79 [0.64–0.97]	0.02
Diphenhydramine		1.7%	1.5%	2.2%	1.4%	0.74 [0.45–1.22]	0.23
Meperidine		2.8%	2.0%	3.9%	1.9%	0.68 [0.45–1.03]	0.07
Prochlorperazine		6.6%	4.5%	5.1%	3.1%	0.89 [0.67–1.19]	0.44
Promethazine		0.1%	0.1%	0.06%	0.03%	0.52 [0.04–7.01]	0.63
Scopolamine		2.1%	1.1%	1.7%	0.6%	0.72 [0.39–1.34]	0.31