Table 1.
Characteristics of the Samples With Scores for Index WOMAC Pain and Other Pain Variablesa
| OAI (n = 3109) [mean, SD or %] | Missing OAI Data (n) | MOST (n = 2165) [mean, SD or %] | Missing MOST Data | |
|---|---|---|---|---|
| Age | 61.8 (9.1) | 0 | 64.5 (8.0) | 0 |
| Sex (% female) | 58.5 | 0 | 61.8 | 0 |
| Race (% African American) | 19.3 | 0 | 14.8 | 0 |
| Modified Charlson Comorbidity (% ≥ 1)b | 25.6% | 39 | 35.8% | 30 |
| Involved knee WOMAC pain scorec | 4.1 (3.6) | 1 | 5.1 (3.8) | 0 |
| Involved generic pain scored | 4.4 (2.4) | 0 | 29.8 (23.7) | 0 |
| Contralateral generic pain score | 2.0 (2.2) | 0 | 15.6 (19.0) | 0 |
| Summed lower extremity pain scoree | 0.81 (1.3) | 75 | 1.5 (1.6) | 326 |
| Back pain severity score (% for each rating) | 76 | 2 | ||
| None | 34.8 | 30.8 | ||
| Mild | 31.8 | 26.7 | ||
| Moderate | 27.1 | 36.8 | ||
| Severe | 6.3 | 5.7 |
a MOST = Multicenter Osteoarthritis Study; OAI = Osteoarthritis Initiative; WOMAC = Western Ontario and McMaster Universities Osteoarthritis.
b The Modified Charlson Comorbidity Index15 score ranges from 0 to 45 with higher scores equating to higher comorbidity burden.
c The WOMAC Pain score ranges from 0 to 20 with higher scores equating to greater pain with activities of daily living.
d The generic pain scale ranges from 0 to 10 for the OAI and 0 to 100 for MOST, with higher scores equating to greater pain.
e The summed lower extremity pain score ranges from 0 to 10 with higher scores equating to worse pain in lower extremity joints other than the knees.