Table 3. Factors affecting anesthetized, nonoperative time in nonfusion spine cases.

	Nonoperative time (min)	p Value
BMI		<0.0001
<25  25–29.9  30–39.9  40+	72 ± 1.2 74 ± 0.6 79 ± 0.6 87 ± 1.8
Age (y)		<0.0001
<65  ≥65	74 ± 0.6 79 ± 0.6
ASA grade		<0.0001
I  II  III  IV	68 ± 1.8 74 ± 0.6 81 ± 0.6 114 ± 9
Level of pathology		<0.0001
Cervical  Thoracic  Lumbar	92 ± 1.2 100 ± 3 72 ± 1.2
Approach		<0.0001
Anterior  Posterior  Combined	113 ± 10 76 ± 0.6 218 ± 31

Abbreviations: ASA, American Society of Anesthesiologists, BMI, body mass index.