Table 5.

The P value of Egger’s test for the vast majority of surgical outcome variables

Time point	ΔVAS scores for low back pain	ΔVAS scores for leg pain	ΔODI values
Postoperative within 3 days	0.36	0.841	0.139
Postoperative 3 months	0.746	0.589	0.657
Postoperative 6 months	0.756	0.451	0.134
Postoperative 12 months	0.589	0.573	0.836

ΔVAS scores, the reduction in VAS score from preoperative to postoperative periods; ΔODI values, the reduction in ODI values from preoperative to postoperative periods.