Table 3.
Clinical outcomes.
| Pre-operation | 1 month | 3 months | 6 months | 12 months | 24 months | p-value‡ | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| K-ODI | ||||||||||||
| Surgery | 23.53 ± 7.51 | 13.06 ± 7.81 | 10.04 ± 5.81 | 7.90 ± 5.66 | 8.07 ± 6.33 | 6.73 ± 6.99 | < .001 | |||||
| Non-surgery | 18.38 ± 7.22 | 12.20 ± 7.11 | 12.06 ± 6.75 | 11.07 ± 5.29 | 7.19 ± 5.19 | 6.00 ± 4.64 | ||||||
| Adjusted mean difference [95% CI]* (p-value†) | − 0.94 [− 3.00, 1.12] (0.37) | |||||||||||
| VAS-B | ||||||||||||
| Surgery | 5.67 ± 2.88 | 2.43 ± 1.88 | 2.33 ± 1.56 | 2.02 ± 1.37 | 2.24 ± 1.73 | 2.00 ± 1.73 | 0.86 | |||||
| Non-surgery | 6.10 ± 2.13 | 3.97 ± 2.17 | 3.38 ± 2.32 | 3.10 ± 2.01 | 2.42 ± 1.67 | 2.35 ± 1.81 | < .001 | |||||
| Adjusted mean difference [99% CI] (p-value) | − 1.31 [− 2.23, − 0.38] (0.002) | − 0.63 [− 1.66, 0.40] (0.57) | − 0.43 [− 1.52, 0.67] (1.00) | 0.08 [− 0.92, 1.07] (1.00) | − 0.04 [− 1.03, 0.95] (1.00) | |||||||
| VAS-L | ||||||||||||
| Surgery | 7.05 ± 2.21 | 2.75 ± 2.34 | 2.12 ± 2.01 | 1.80 ± 1.65 | 2.28 ± 2.12 | 1.98 ± 1.80 | 0.12 | |||||
| Non-surgery | 6.27 ± 2.06 | 3.97 ± 2.24 | 3.68 ± 2.31 | 3.20 ± 2.23 | 2.15 ± 1.97 | 2.16 ± 2.04 | < .001 | |||||
| Adjusted mean difference [99% CI] (p-value) | − 1.34 [− 2.41, − 0.28] (0.01) | − 1.32 [− 2.51, − 0.14] (0.02) | − 1.12 [− 2.38, 0.14] (0.11) | 0 [− 1.14, 1.14] (1.00) | − 0.25 [− 1.39, 0.89] (1.00) | |||||||
| EQ-5D utility score | ||||||||||||
| Surgery | 0.43 ± 0.19 | 0.73 ± 0.15 | 0.78 ± 0.08 | 0.81 ± 0.09 | 0.81 ± 0.13 | 0.84 ± 0.12 | < .001 | |||||
| Non-surgery | 0.57 ± 0.17 | 0.73 ± 0.13 | 0.75 ± 0.15 | 0.79 ± 0.08 | 0.82 ± 0.10 | 0.83 ± 0.10 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 0.00 [− 0.04, 0.04] (0.96) | |||||||||||
| EQ-5D VAS | ||||||||||||
| Surgery | 49.02 ± 18.14 | 71.23 ± 18.45 | 77.76 ± 15.04 | 79.95 ± 13.38 | 79.91 ± 9.30 | 80.45 ± 11.60 | < .001 | |||||
| Non-surgery | 55.28 ± 16.56 | 67.03 ± 17.87 | 73.09 ± 15.76 | 75.83 ± 10.09 | 80.58 ± 9.90 | 77.55 ± 11.72 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 3.23 [− 0.73, 7.2] (0.11) | |||||||||||
| SF-36 (VT) | ||||||||||||
| Surgery | 36.05 ± 16.22 | 52.74 ± 16.54 | 54.59 ± 16.42 | 55.61 ± 15.42 | 53.48 ± 17.32 | 56.70 ± 17.45 | 1.00 | |||||
| Non-surgery | 40.14 ± 16.99 | 47.77 ± 17.34 | 50.15 ± 19.67 | 49.67 ± 21.85 | 58.13 ± 16.75 | 57.55 ± 14.23 | < .001 | |||||
| Adjusted mean difference [99% CI] (p-value) | 7.25 [− 0.73, 15.23] (0.10) | 3.43 [− 5.44, 12.31] (1.00) | 3.56 [− 5.81, 12.93] (1.00) | − 2.72 [− 11.25, 5.82] (1.00) | − 0.45 [− 8.94, 8.05] (1.00) | |||||||
| SF-36 (PF)†† | ||||||||||||
| Surgery | 30.35 ± 23.75 | 58.30 ± 27.03 | 71.33 ± 22.19 | 75.37 ± 21.08 | 75.87 ± 23.05 | 80.80 ± 22.87 | < .001 | |||||
| Non-surgery | 47.25 ± 25.87 | 62.31 ± 24.48 | 65.29 ± 22.89 | 68.17 ± 19.23 | 79.69 ± 17.12 | 82.25 ± 14.98 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 0.99 [− 6.19, 8.17] (0.79) | |||||||||||
| SF-36 (BP) | ||||||||||||
| Surgery | 20.44 ± 17.15 | 58.77 ± 22.70 | 68.47 ± 19.69 | 73.48 ± 22.37 | 71.79 ± 20.34 | 73.07 ± 22.21 | < .001 | |||||
| Non-surgery | 33.52 ± 16.70 | 53.08 ± 24.21 | 61.76 ± 23.25 | 67.83 ± 19.95 | 75.73 ± 18.23 | 76.13 ± 17.19 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 3.13 [− 3.45, 9.71] (0.35) | |||||||||||
| SF-36 (GH) | ||||||||||||
| Surgery | 53.07 ± 18.99 | 61.23 ± 19.19 | 62.86 ± 20.34 | 65.37 ± 19.86 | 58.59 ± 19.37 | 66.70 ± 17.85 | 0.04 | |||||
| Non-surgery | 50.92 ± 17.47 | 55.31 ± 17.54 | 51.03 ± 17.31 | 58.17 ± 20.40 | 62.29 ± 18.04 | 66.08 ± 17.13 | < .001 | |||||
| Adjusted mean difference [99% CI] (p-value) |
3.93 [− 3.96, 11.82] (0.99) |
8.01 [− 0.73, 16.74] (0.09) | 1.15 [− 8.07, 10.38] (1.00) | − 7.08 [− 15.52, 1.35] (0.15) | − 3.01 [− 11.4, 5.38] (1.00) | |||||||
| SF-36 (RP) | ||||||||||||
| Surgery | 15.35 ± 27.85 | 39.15 ± 39.38 | 51.53 ± 40.64 | 64.02 ± 37.10 | 60.33 ± 41.69 | 17.05 ± 28.41 | < .001 | |||||
| Non-surgery | 22.89 ± 32.39 | 39.23 ± 40.26 | 45.59 ± 41.96 | 72.50 ± 36.17 | 59.90 ± 41.17 | 27.45 ± 35.45 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 2.75 [− 5.56, 11.07] (0.52) | |||||||||||
| SF-36 (RE) | ||||||||||||
| Surgery | 38.01 ± 36.43 | 59.12 ± 44.16 | 67.35 ± 41.66 | 73.98 ± 41.17 | 59.42 ± 48.13 | 6.06 ± 21.89 | < .001 | |||||
| Non-surgery | 48.36 ± 40.15 | 60.51 ± 42.45 | 61.76 ± 43.53 | 86.67 ± 28.50 | 67.36 ± 45.35 | 22.22 ± 40.37 | ||||||
| Adjusted mean difference [95% CI] (p-value) | − 0.80 [− 10.35, 8.75] (0.87) | |||||||||||
| SF-36 (SF) | ||||||||||||
| Surgery | 35.75 ± 20.24 | 58.02 ± 22.61 | 69.39 ± 21.51 | 75.61 ± 22.18 | 74.73 ± 23.35 | 79.83 ± 22.59 | < .001 | |||||
| Non-surgery | 47.18 ± 22.97 | 58.08 ± 23.53 | 60.29 ± 22.92 | 70.83 ± 18.08 | 79.69 ± 20.08 | 76.47 ± 19.63 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 2.65 [− 3.89, 9.20] (0.43) | |||||||||||
| SF-36 (MH) | ||||||||||||
| Surgery | 49.54 ± 18.19 | 67.77 ± 17.67 | 71.84 ± 17.28 | 75.41 ± 17.74 | 73.13 ± 17.32 | 76.18 ± 16.32 | < .001 | |||||
| Non-surgery | 56.85 ± 18.13 | 64.68 ± 15.63 | 64.59 ± 17.54 | 67.87 ± 15.84 | 74.58 ± 12.03 | 73.88 ± 14.56 | ||||||
| Adjusted mean difference [95% CI] (p-value) | 3.96 [− 0.58, 8.49] (0.09) | |||||||||||
VAS-B visual analogue scale for back pain, VAS-L visual analogue scale for leg pain, K-ODI Korean version of the Oswestry Disability Index, EQ-5D score EuroQol 5-Dimension instrument score, EQ-VAS EuroQol visual analogue scale, SF-36 36-Item Short-Form Health Survey.
The results from the linear mixed effects model (*adjusted mean difference between surgery and non-surgery cohort, confidence intervals are represented according to statistical significance; †cohort difference; ‡ time difference).
††The SF-36 consists of eight sections, including vitality (VT), physical functioning (PF), bodily pain (BP), general health perceptions (GH), physical role functioning (RP), emotional role functioning (RE), social role functioning (SF) and mental health (MH).