Table 1.
Summary statistics of the baseline characteristics
| Variable | Chronic pain duration classification | P value | ||
|---|---|---|---|---|
| < 1 year | 1 ~ 5 years | > 5 years | ||
| (N = 110) | (N = 110) | (N = 110) | ||
| Age, yr (mean ± SD) | 54.48 ± 9.94 | 55.06 ± 10.30 | 56.36 ± 8.68 | 0.320 |
| Female (%) | 67 (60.91) | 64 (58.18) | 69 (62.73) | 0.482 |
| BMI (mean ± SD) | 24.48 ± 3.11 | 24.12 ± 3.77 | 24.03 ± 3.67 | 0.619 |
| Operation history (%) | 0.788 | |||
| 0 | 30 (27.27) | 33 (30.00) | 31 (28.18) | |
| 1 | 47 (42.73) | 41 (37.27) | 46 (41.82) | |
| ≥ 2 | 33 (30.00) | 36 (32.73) | 33 (30.00) | |
| Smoking (%) | 40 (36.36) | 43 (39.09) | 39 (35.45) | 0.359 |
| Level of preoperative pain (VAS) (mean ± SD) | 1.71 ± 0.65 | 1.88 ± 0.69 | 2.07 ± 0.71 | < 0.05* |
| SAS (mean ± SD) | 36.91 ± 6.72 | 40.03 ± 6.59 | 43.25 ± 6.36 | < 0.05* |
| SDS (mean ± SD) | 39.31 ± 7.21 | 42.35 ± 6.83 | 46.25 ± 7.28 | < 0.05* |
| FRAIL (mean ± SD) | 1.71 ± 0.70 | 1.66 ± 0.76 | 1.74 ± 0.75 | 0.760 |
| Duration of surgery, min (mean ± SD) | 121.01 ± 8.69 | 122.99 ± 9.40 | 123.75 ± 10.69 | 0.088 |
| Etiology of back pain(%) | 0.817 | |||
| spinal stenosis | 57 (51.82) | 51 (46.36) | 49 (44.55) | |
| spondylolisthesis | 34 (30.91) | 37 (33.67) | 41 (37.27) | |
| disc herniation | 19 (17.27) | 22 (19.97) | 20 (18.18) | |
One-way ANOVA and chi-square tests were used to identify the differences among the three groups for some variables
BMI Body mass index, VAS Visual analogue scale for pain, SAS Self-rating Anxiety Scale, SDS Self-rating Depression Scale, FRAIL FRAIL scale, SD Standard deviation, yr Year
*P < 0.05; significant difference among the three groups