Results of the between-groups post-hoc comparisons of the change in pain outcomes after controlling for baseline scores in a multivariable mixed-effects regression model.
| Comparison | Estimated Differencea | 95% CI | P | ||
| Lower | Upper | ||||
| Change in VAS back painb | |||||
| 3 mo | 6 mo | 5.30 | 3.92 | 6.68 | <0.001c |
| 6 mo | 12 mo | 1.47 | 0.04 | 2.90 | 0.13 |
| 3 mo | 12 mo | 6.77 | 5.36 | 8.18 | <0.001c |
| <40 y | 40–65 y | 2.37 | −0.30 | 5.04 | 0.25 |
| 40–65 y | >65 y | 1.45 | −3.02 | 5.92 | >0.99 |
| <40 y | >65 y | 0.92 | −3.97 | 5.80 | >0.99 |
| Brantigan | STALIF | 2.51 | −0.19 | 5.20 | 0.21 |
| STALIF | Australis | 3.01 | 0.25 | 5.77 | 0.10 |
| Brantigan | Australis | 5.51 | 2.84 | 8.19 | <0.001c |
| Higher ALIF | Lower ALIF | 7.49 | 1.83 | 13.14 | 0.010c |
| Change in VAS leg paina | |||||
| 3 mo | 6 mo | 7.86 | 6.31 | 9.41 | <0.001c |
| 6 mo | 12 mo | 0.64 | −0.97 | 2.25 | >0.99 |
| 3 mo | 12 mo | 8.50 | 6.91 | 10.09 | <0.001c |
| <40 y | 40–65 y | 4.36 | 1.92 | 6.80 | 0.001c |
| 40–65 y | >65 y | 6.60 | 2.33 | 10.87 | 0.007c |
| <40 y | >65 y | 10.96 | 6.34 | 15.58 | <0.001c |
| Brantigan | STALIF | 2.26 | −0.27 | 4.79 | 0.24 |
| STALIF | Australis | 1.89 | −0.66 | 4.44 | 0.44 |
| Brantigan | Australis | 4.15 | 1.63 | 6.68 | 0.004c |
| Higher ALIF | Lower ALIF | 0.49 | −4.72 | 5.70 | 0.85 |
Abbreviations: ALIF, anterior lumbar interbody fusion; VAS, visual analog scale.
↵a The estimated difference is the more significant improvement experienced by the category in bold text for each pairwise comparison. None of the estimated differences between groups were clinically significant.
↵b The estimated mean improvement at 3 months postsurgery for a <40-year-old patient with mean baseline, Brantigan cage, and higher ALIF were 44.7 for back pain and 26.6 for leg pain.
↵c Statistically significant difference P < 0.05.