Table 6.

Sub-Group Analysis of Changes in PROs From 1 to 2-Year Postoperative.

Sub-group analysis (significant results only)
	1-year postop	2-year postop	P-value
1. Age >55Y
ODI, median (IQR)	18 (4-28)	8 (0-26)	.047*
% achieving MCID	73%	84%	.048*
2. Global alignment
Combined coronal/sagittal malalignment  % achieving MCID SRS-appearance	75%	100%	.050*
No significant changes for coronal malalignment-only or sagittal malalignment only
3. Severity of deformity
Severe sagittal malalignment >7.5 cm  % achieving MCID SRS-appearance	73%	100%	.032*
No significant changes for severe coronal malalignment >5 cm or max Cobb angle >60°
4. Invasiveness of surgery
No significant changes for 3 column osteotomy or total instrumented levels
5. Complication status
No significant changes for complication or reoperation

* Denotes statistically significant.