Table 4 Predictors of NRS and FRI 6 months after radiofrequency

Dependent variables

Independent variables

B

P-value

95% CI

Adjusted R Squared

Lower bound

Upper bound

NRS 6 months after radiofrequency

Constant

-8.042

0.098

-17.643

1.559

0.394

Age

0.043

0.098

-0.008

0.094

Duration of pain in months

0.040

0.202

-0.022

0.101

Number of prolapsed discs

-0.526

0.135

-1.224

0.172

NRS before radiofrequency

0.775

0.040

0.036

1.514

FRI before radiofrequency

-0.036

0.116

-0.082

0.009

BDNF serum level before radiofrequency in ng/ml

0.181

0.547

-0.421

0.783

S100B serum level before radiofrequency in ng/ml

1.237

< 0.001

0.602

1.872

FRI 6 months after radiofrequency

Constant

-75.21

0.057

-152.737

2.314

0.445

Age

0.156

0.452

-0.259

0.571

Duration of pain in months

0.806

0.002

0.308

1.303

Number of prolapsed discs

-1.038

0.712

-6.673

4.597

NRS before radiofrequency

3.909

0.193

-2.057

9.875

FRI before radiofrequency

0.088

0.634

-0.281

0.457

BDNF serum level before radiofrequency in ng/ml

2.265

0.352

-2.596

7.125

S100B serum level before radiofrequency in ng/ml

8.021

0.003

2.894

13.148