Table 4 Regression analysis and odds ratio (OR) of having low back pain at 24 h

Gender (male/female)

1.02

0.34–3.02

0.971

1.05

0.32–3.40

0.935

Age

1.02

0.98–1.05

0.336

1.01

0.98–1.05

0.455

Try (two/one)

4.70

2.04–10.84

< 0.001

4.27

1.79–10.18

0.001

Injection site (L4–L5/L3–L4)

2.42

1.05–5.59

0.039

1.91

0.78–4.66

0.158

Group (paramedian/median)

1.28

0.58–2.82

0.545

0.90

0.37–2.16

0.804