Table 1. Characteristics of the Samples at baseline and missing baseline data for each predictor variable.
| OAI (n = 2,422) (R knee =1,904, L knee = 1,978) [mean, SD or %] | OAI missing data (n, % or R, %, L, %) | MOST (n = 1,690) R knee = 1,387, L knee =1,457) [mean, SD or %] | MOST missing data (n, % or R, %, L, %) | |
|---|---|---|---|---|
| Age | 60.5, 9.1 | 0 | 61.2, 7.7 | 0 |
| Sex (% female) | 55.5% | 0 | 58.3% | 0 |
| Race (% African American) | 12.2% | 3, <1% | 12.2% | 0 |
| Body Mass Index (Kg/m2) | 27.9, 4.4 | 0 | 29.7, 5.2 | 1, <1% |
| Multiple joint OA | 12.2% | 67, 3.5%, 71, 3.6% | 10.9% | 0 |
| Contralateral knee OA (R,L) | 18.1%, 21.0% | 7, <1%, 11, <1% | 12.5%, 16.7% | 13, <1%, 10, <1% |
| Baseline K&L grade of 1 (R,L) | 34.7%, 32.7% | 0, 0 | 29.1%, 27.5% | 0, 0 |
| Prior Knee Surgery (R,L) | 11.0%, 10.7% | 2, <1%, 3, <1% | 8.9%, 10% | 1, <1%, 1, <1% |
| Prior Knee injury (R,L) | 27.2%, 24.2% | 24, 1.4%, 17, <1% | 25.1%, 22.1% | 6, <1%, 4, <1% |
| Knee alignment (R,L) | -1.0, 3.1, -1.1, 3.0 | 324, 17%, 324, 16.4% | -1.0, 3.1, -1.1, 3.0 | 13, <1%, 18, 1% |
| Frequent knee pain (R,L) | 22%, 23.0% | 10, <1%, 9, <1% | 27.9%, 34.5%, | 3,<1%, 2, <1% |
| WOMAC total score (R,L) | 9.1, 12.0, 9.0, 13.3 | 6, <1%, 9, <1% | 15.8, 15.5, 15.5, 15.3 | 5, <1%, 1, <1% |
| CESD depression score | 6.1, 6.4 | 24, 1% | 6.8, 7.3 | 1, <1% |
| K&L Grade 0 to 2 (R,L) | 47/1244, 36/1332 | 73/986, 73/1057 | ||
| K&L Grade 0 to 3 (R,L) | 21/1244, 18/1332 | 50/986, 54/1057 | ||
| K&L Grade 0 to 4 (R,L) | 2/1244, 1/1332 | 2/986, 3/1057 | ||
| K&L Grade 1 to 2 (R,L) | 82/660, 102/646 | 111/401, 117/400 | ||
| K&L Grade 1 to 3 (R,L) | 40/660, 29/646 | 87/401, 72/400 | ||
| K&L Grade 1 to 4 (R,L) | 6/660, 5/646 | 8/401, 6/400 |