Table 4 Covariates for subanalysis

1

Age and age banding ( < 60 years, > 60 years or similar linked to groups size after recruitment)

2

Long medical history of back pain

3

Leg pain intensity

4

Proportion leg pain/back pain

5

Extent of stenosis during MRI examination

6

Kind of stenosis (soft or bony)

7

Sexe

8

Surface area of spinal canal