Table 1.

Baseline Characteristics of the Sample Included in the Case-Control Study

Characteristic	Control n=406	Case (radiographic and pain progression) n=194
Age	61.3 (8.9)	62.0 (8.8)
Sex
Male	163 (40%)	84 (43%)
Female	243 (60%)	110 (57%)
BMI	30.7 (4.8)	30.7 (4.8)
History of knee injury*
No	260 (64%)	125 (65%)
Yes	145 (36%)	68 (35%)
Baseline Kellgren Lawrence grade (KLG)
1	51 (13%)	24 (12%)
2	222 (55%)	84 (43%)
3	133 (33%)	86 (44%)
Baseline WOMAC Pain score; mean (SD)	13.0 (16.7)	10.2 (13.0)
Baseline JSW; mean (SD)	3.9 (1.1)	3.8 (1.4)

^*Ever injured knee badly enough to limit ability to walk for at least two days