Table 3.

Univariate analysis result of variables

Variables	P-value*
Age	0.03
Sex	0.12‡
Total medical cost	0.00
Duration of hospital stay	0.00
Insurance types	0.24†
Spine surgery type: lumbar	0.00
Spine surgery approach: anterior	0.00
Infection	0.18‡
Diabetes	0.34†
Hypertension	0.01
Use of NSAIDs	0.01
Invasive procedures	0.39†
Bleeding factors	0.00
Trauma	0.31†
Anticoagulant use	0.51†
Surgical time: >  2 h	0.00
Blood loss: >  0.5 L	0.00
Type of hospital: small hospitals	0.09‡
Number of hospital beds: >  200	0.03
Location of hospital: rural area	0.00

*Variables with a dagger (†) mean that the P-value of the corresponding variable is not statistically significant. Variables with a double dagger (‡) means that the P-value of the corresponding variable is located between 0.05 and 0.20, indicating marginal significance. A P-value of 0.00 indicates a P-value < 0.001