Table 4.

Univariate Regression of Demographic, Preoperative and Intraoperative Characteristics for Chronic Steroid Users (subgroup) Undergoing Elective PLF.

	No Significant Complication		≥1 Significant Complication
	n	%	n	%	P
Age
≥65 years	250	44.2	194	68.6	<.0001
Sex
Male	239	42.2	70	24.7	<.0001
Female	327	57.8	213	75.3
Race
White	488	86.4	236	83.4	.6521
Black	37	6.6	23	8.1
Hispanic	5	0.9	2	0.7
Other	35	6.2	22	7.8
Medical comorbidities
Diabetes	98	17.3	78	27.6	.0005
Smoking	96	17.0	31	11.0	.0207
Pulmonarya	84	14.8	63	22.3	.0071
Cardiacb	367	64.8	217	76.7	.0004
Renalc	2	0.4	1	0.4	1
Bleeding disorder	14	2.5	14	5.0	.0571
Underweight	0	0.0	8	2.8	<.0001
Obese class III	30	5.3	32	11.3	.0015
Preoperative condition
ASA class ≥3	369	65.3	230	81.3	<.0001
Dyspnea at rest	54	9.5	40	14.1	.0443
Independent	543	96.8	255	90.8	.0002
Poor functional statusd	18	3.2	26	9.3
Operative variables
Long fusion ≥4 levels	178	31.5	129	465.6	<.0001
Short fusion ≤3 levels	388	68.6	154	54.4
Pelvic fixation	6	1.1	7	2.5	.1139
Inpatient surgery	550	97.2	281	99.3	.0432
Outpatient surgery	16	2.8	2	0.7
Operation in 2011	67	11.8	38	13.4	.897
Operation in 2012	116	20.5	54	19.1
Operation in 2013	175	30.9	86	30.4
Operation in 2014	208	36.8	105	37.1
Extended operative time	150	26.5	106	37.5	.001

Abbreviations: ASA, American Society of Anesthesiologists; PLF, posterior lumbar fusion.

^a Pulmonary comorbidity was defined as a history of chronic obstructive pulmonary disease of ventilator dependence within 48 hours prior to surgery.

^b Cardiac comorbidity was defined as the use of hypertensive medication or a history of chronic heart failure.

^c Renal comorbidity was defined as dialysis treatment within 2 weeks prior to surgery or acute renal failure within 24 hours prior to surgery.

^d Poor functional status was defined as partial or total dependence prior to surgery.