Table 2. Estimated Cobb angle trajectories and the effects of age and surgery on trajectory, measured as percent change.

Trajectory parameter	Estimate	95% CI	P value
Predicted first measurement for 9 yr old.	14.7	(10.6, 20.1)	<0.001
Percent change per year older at baseline	2%	(-1%, 6%)	0.18
Percent change per year of follow-up	31%	(18%, 45%)	<0.001
Percent change immediately after surgery	-50%	(-56%, -43%)	<0.001
Percent change per year in post-op period (P value compared to pre-op change per yr)	11%	(0%, 23%)	<0.001