Table 3 Logistic regression models showing adjusted odds ratios (with 95% confidence intervals) of predictors at different follow-ups with respect to a less than 30% decrease in disability and pain from baseline: a multivariate analysis with all the predictors entered into the model at the same time.

Model 1, preoperative:

Age (years)

1.00 (0.96-1.04)

p = 0.96

1.00 (0.96-1.05)

p = 0.85

Gender (male: no/yes)

1.46(0.58-3.66)

p = 0.43

1.52 (0.57-4.05)

p = 0.41

Marital status (single: no/yes)

1.40 (0.54-3.59)

p = 0.49

1.25 (0.45-3.43)

p = 0.67

Stucki symptom severity (continuous score)

0.77 (0.30-1.96)

p = 0.58

1.36 (0.48-3.85)

p = 0.56

Stucki disability (continuous score)

1.50 (0.45-4.96)

p = 0.51

0.30 (0.08-1.14)

p = 0.37

Depressive symptoms (BDI ≥ 10: no/yes)

1.86 (0.72-4.81)

p = 0.20

1.60 (0.57-4.48)

p = 0.37

^◆) Model 2,

3-month follow-up:

Depressive symptoms (BDI ≥ 10: no/yes)

2.94 (1.06-8.12)*

p = 0.04

3.33 (1.13-9.79)*

p = 0.03

Model 3,

6-month follow-up:

Depressive symptoms

(BDI ≥ 10: no/yes)

4.94 (1.35-18.09)*

p = 0.02

2.83 (0.77-10.42)

p = 0.12

Model 4,

1-year follow-up:

Depressive symptoms

(BDI ≥ 10: no/yes)

2.91 (0.99-8.53)

p = 0.05

2.05 (0.71-5.93)

p = 0.19