TABLE 2.

Relationships between patient clinicodemographic variables and 12-month postoperative improvement in NDI score

Variable*	T-Statistic†	p Value
Female gender‡	−2.10	0.036
Axial pain‡	−3.21	0.0013
Medicare insurance‡	−2.77	0.0058
Private insurance‡	−2.75	0.0062

^*Only includes covariates that were significant (p < 0.05) in the multivariate GLM.

^†A negative t-statistic indicates a greater association with reduction in 12-month NDI score.

^‡Significant (p < 0.05) predictors of 12-month postoperative NDI score.