Table 2.

Preoperative Characteristics for the Propensity Score Matched Cohorts

	Use of midazolam (weighted)	No midazolam	p-value	Standardized Difference*
n	357	357
Age (yr), mean ± SD	74.1±4.2	74.5±6.6	0.35	0.06
Female, n (%)	182.2 (51.0%)	169 (47.3%)	0.36	−0.07
Charlson, mean ± SD	1.2±1.2	1.2±1.4	0.63	−0.03
ASA Classification, n (%)
I – II	190.5 (53.4%)	191 (53.5%)	1.00	0.00
III – V	166.5 (46.6%)	166 (46.5%)
TICS score, mean ± SD	32.9±2.6	32.7±4.2	0.52	−0.04
Preoperative use of benzodiazepine, n (%)	30.8 (8.6%)	30 (8.4%)	1.00	0.01
Surgical site, n (%)
Hip	62.3 (17.5%)	77 (21.6%)	0.48	−0.03
Knee	65 (18.2%)	55 (15.4%)
Spine	137.7 (38.6%)	137 (36.4%)
Other	92 (25.8%)	88 (24.7%)
Year, n (%)
< 2010	223.3 (62.6%)	222 (62.2%)	0.98	−0.01
≥ 2010	132.7 (37.4%)	135 (37.8%)

Abbreviations: ASA, American Society of Anesthesiology; SD, standard deviation; TICS, Telephone Interview for Cognitive Status.

^*Standardized Difference: the difference in means or proportions divided by the pooled standard deviation