Table 2 Results of multivariate analysis

Age

1.00

0.98–1.01

0.557

Coexisting disease

1.31

0.92–1.89

0.137

Radiating pain

1.56

0.69–3.54

0.288

Intensity of injection pain

1.19

0.90–1.58

0.228

Duration of anesthesia (per 10 min)

1.02

1.01–1.03

0.0007

Surgical site

 Abdominal

1

NA

NA

 Extremity

12.5

2.77–56.4

0.001

 Thoracic

1.34

0.93–1.01

0.118

Transfusion

1.43

0.95–2.16

0.083

Adverse event

1.88

0.37–9.61

0.449

Intensity of postoperative pain

1.21

0.97–1.51

0.098

Postoperative headache

1.78

1.08–2.95

0.024

Days taken to visit postoperative anesthesia clinic

1.03

10.1–1.06

0.008