Incidence and risk factors of spinal epidural hemorrhage after spine surgery: a cross-sectional retrospective analysis of a national database

Table 4 Multivariable logistic regression results

Risk factors	P > \|z\|*	OR (95% CI)
Spine surgery approach: anterior	0.03	0.43 (0.20–0.90)
Spine surgery type: lumbar	0.01	1.75 (1.15–2.65)
Blood loss: > 0.5 L	0.00	2.11 (1.31–3.41)
Surgical time: > 2 h	0.00	7.22 (3.82–13.67)
Hypertension	0.03	1.41 (1.04–1.90)
Use of NSAIDs	0.01	7.30 (1.70–31.44)
Bleeding factors	0.00	1.92 (1.41–2.62)
Anticoagulant use	0.08	0.66 (0.42–1.05)
Type of hospital: small hospitals^a	0.03	1.48 (1.05–2.08)
Location of hospital: rural area	0.00	3.11 (2.32–4.18)

OR odds ratio, CI confidence interval
*P-value of 0.00 is p-value < 0.001.
^aIn the Korean health care system, the hospitals are classified into four categories, based on their function and size. From largest to smallest, they are tertiary general hospital, general hospital, hospital, and clinic. Small hospitals include hospital and clinic

ISSN: 1471-2474