Table 1.
Baseline characteristics of the cases and controls in the study group
| Per Person
|
|||||||
|---|---|---|---|---|---|---|---|
| All (n=677) | Cases (n=322) | Controls (n=355) | p value | ||||
|
| |||||||
| Mean | SD | Mean | SD | Mean | SD | ||
| Age (Years) | 60.2 | (8.6) | 60.3 | (8.7) | 60.1 | (8.4) | 0.8061 |
| BMI | 28.3 | (4.5) | 28.9 | (4.5) | 27.7 | (4.4) | 0.0006 |
| Height (mm) | 1670.0 | (87.9) | 1671.7 | (91.0) | 1668.3 | (85.0) | 0.6114 |
| Weight (kg) | 79.1 | (15.2) | 80.8 | (15.0) | 77.5 | (15.3) | 0.0053 |
| BMI (categorical) | N | % | N | % | N | % | |
| Normal | 167 | (25.0) | 62 | (19.3) | 105 | (30.4) | 0.0031 |
| Overweight | 267 | (40.0) | 135 | (41.9) | 132 | (38.3) | |
| Obese | 233 | (34.9) | 125 | (38.8) | 108 | (31.3) | |
| Sex | N | % | N | % | N | % | |
| 1: Male | 222 | (33.3) | 109 | (33.9) | 113 | (32.8) | 0.8053 |
| 2: Female | 445 | (66.7) | 213 | (66.1) | 232 | (67.2) | |
| # of Knee bending activities (past 30 days) | |||||||
| N | % | N | % | N | % | ||
| None | 63 | (9.5) | 26 | (8.1) | 37 | (10.7) | 0.0631 |
| 1, 2 or 3 | 497 | (74.5) | 234 | (72.7) | 263 | (76.2) | |
| 4 or 5 | 107 | (16.0) | 62 | (19.3) | 45 | (13.0) | |
| Per Knee
|
|||||||
|---|---|---|---|---|---|---|---|
| All (n=708) | Cases (n=354) | Controls (n=354) | p value | ||||
|
| |||||||
| class | N | % | N | % | N | % | |
| 1 (KL 0/0) | 126 | (17.8) | 63 | (17.8) | 63 | (17.8) | 1.0000 |
| 2 (KL 0/1) | 152 | (21.5) | 76 | (21.5) | 76 | (21.5) | |
| 3 (KL 1/1) | 166 | (23.4) | 83 | (23.4) | 83 | (23.4) | |
| 4 (KL 0/2+) | 118 | (16.7) | 59 | (16.7) | 59 | (16.7) | |
| 5 (KL 1/2+) | 146 | (20.6) | 73 | (20.6) | 73 | (20.6) | |
| Baseline knee injury | 206 | (29.1) | 136 | (38.4) | 70 | (19.8) | < 0.0001 |
| Baseline knee surgery | 78 | (11.0) | 54 | (15.3) | 24 | (6.8) | 0.0004 |
Test of group differences by t-test, Chi-Squared, and Fisher’s Exact. BMI, body mass index. KL, Kellgren-Lawrence.