Group Severe Moderate Mild     L2/3 L3/4 L4/5 L5/S1 L2/3 L3/4 L4/5 L5/S1 L2/3 L3/4 L4/5 L5/S1 Primary* I 0 0 11 1 1 4 15 3 0 5 17 3 II 0 3 6 0 1 2 15 3 0 2 22 6   Total 0 3 17 1 2 6 30 6 0 7 39 9                             Secondary I 0 0 0 0 0 5 1 2 0 1 1 3 II 0 0 0 0 0 0 4 1 0 1 2 3   Total           5 5 3   2 3 6 *Primary: Indicates worst level of stenosis or same type stenosis at multiple levels in participants with multiple level stenosis and all participants with single level stenosis

Table 2: Lumbar central spinal stenosis: Severity and involved level(s) as classified by radiologist(s) (MRI or CT scan).