Table 2.

Assigned values of the parameters of age, body mass index (BMI), disc degeneration, sagittal range of motion, lumbar lordosis angle, and sacral slope before logistic regression analysis.

Factor	Variable		Assignment description
Age	X1	<50.361=1; ≥50.361=2	Average (47.744+52.978)/2=50.361
Body mass index (BMI)	X2	<24.581=1; ≥24.581=2	Average (23.585+25.576)/2=24.581
Disc degeneration	X3	I=1; II=2; III=3; IV=4
Sagittal range of motion	X4	<9.581=1; ≥9.581=2	Average (8.066+11.096)/2=9.581
Lumbar lordosis angle	X5	<41.347=1; ≥41.347=2	Average (39.304+43.389)/2=41.347
Sacral slope	X6	<31.585=1; ≥31.585=2	Average (29.083+34.087)/2=31.585
Recurrence	Y	Yes=1; No=2