Table 1. Characteristics of Study Samples.
| Characteristic | Total Sample (N=1522) | Symptomatic OA Subsample (N=445) |
|---|---|---|
| Demographic | ||
| Mean (SD) Age in years* | 68.1 (9.0) | 69.9 (9.0) |
| % Women* | 66.6 | 74.0 |
| % African American | 31.1 | 33.5 |
| % With ≥12 Years Education* | 78.4 | 69.1 |
| % Married or Living with Partner* | 59.5 | 52.4 |
| % Currently Employed* | 32.9 | 23.7 |
| Mean (SD) of % Poverty Households in block group* | 16.2 (10.2) | 18.0 (10.6) |
| Health Insurance Type (%*) | ||
| No Health Insurance | 5.2 | 4.3 |
| Government Only | 29.9 | 35.3 |
| Non-Government Only | 26.1 | 15.7 |
| Government + Non-Government | 38.7 | 44.7 |
| Health-Related | ||
| % With Excellent, Very Good, Good Self-Rated Health* | 76.4 | 61.4 |
| Mean (SD) BMI* † | 31.3 (7.2) | 33.8 (8.4) |
| Median (IQR‡) Depressive Symptoms (CES-D§)* | 4 (1-9) | 6 (2-12) |
| Median (IQR) Social Support* ‖ | 19 (16-20) | 18 (16-20) |
| OA Related | ||
| Median (IQR) WOMAC¶ Score of Worst Knee or Hip* | 7 (0-31) | 34 (17-50) |
| Mean Symptom Duration (SD) (Longest number years for knee or hip) | 10.6 (10.6) | 11.6 (11.3) |
| % Distribution of the Number of Knee / Hip Joints with KL ≥ 2 OA * | ||
| 0 | 36.5 | 0 |
| 1 | 21.6 | 21.8 |
| 2 | 27.3 | 47.6 |
| 3 | 8.1 | 16.0 |
| 4 | 6.5 | 14.6 |
| % Distribution of the KL Grade of Worst Knee or Hip Joint * | ||
| 0-1 | 36.5 | N/A |
| 2 | 34.6 | 36.6 |
| 3 | 14.1 | 25.2 |
| 4 | 14.8 | 38.2 |
*
Statistically significant difference (p<0.05) between Total Sample and Symptomatic OA Subsample; Chi-square for categorical variables, t-test to compare means of continuous variables, Wilcoxon-Mann-Whitney to compare medians of continuous variables.
†
BMI=kg/m2; BMI≥30 in kg/m2 defined as obese
‡
IQR = Interquartile Range
§
CES-D range 0-60; higher scores indicate presence of more depressive symptoms
‖
Strong Ties Measure of Social Support range 0-20; higher scores indicate more social support
¶
WOMAC range 0-96; higher scores indicate worse pain/function