Table 1.
Baseline demographic and clinical characteristics of the study sample*
| Variable | Control (n = 253) |
Treatment (n = 240) |
p value† |
|---|---|---|---|
| Recruitment site, number (%) | 0.696 | ||
| University of Pennsylvania | 135 (53) | 131 (55) | |
| University of Pittsburgh | 16 (6) | 19 (8) | |
| Philadelphia Veterans Administration | 102 (40) | 90 (38) | |
| Demographic characteristics‡ | |||
| Age, years | 61.14 ± 7.86 | 62.02 ± 8.09 | 0.224 |
| Sex, number of (%) men | 124 (49) | 118 (49) | 0.973 |
| Number (%) with less than high school education | 53 (21) | 50 (21) | 0.975 |
| Number (%) currently working | 56 (22) | 48 (20) | 0.562 |
| Number (%) currently married | 61 (24) | 69 (29) | 0.242 |
| Number (%) living alone | 111 (44) | 112 (47) | 0.560 |
| Number (%) with annual household income less than USD 15,000 | 125 (54) | 109 (49) | 0.357 |
| Clinical characteristics | |||
| WOMAC | 59.51 ± 13.21 | 58.69 ± 14.16 | 0.510 |
| Arthritis Self-Efficacy pain | 25.31 ± 10.28 | 26.43 ± 10.19 | 0.231 |
| Arthritis Self-Efficacy function | 52.21 ± 18.25 | 55.28 ± 17.99 | 0.061 |
| Charlson comorbidity index | 3.33 ± 2.22 | 3.07 ± 2.05 | 0.182 |
| SF-12® Physical Component | 31.00 ± 9.79 | 32.58 ± 9.79 | 0.085 |
| SF-12® Mental Component | 45.96 ± 8.99 | 46.19 ± 8.47 | 0.775 |
| Number (%) willing to undergo TKA§ | 170 (67) | 164 (69) | 0.634 |
*Except where indicated otherwise, values are mean ± SD; †t-tests for continuous variables, chi-square tests for categorical variables; ‡there were slight variations in the number of patients who provided information for some of the demographic characteristics. Most had two or fewer patients missing data. The income variable had the highest number of patients with missing data (39 subjects did not provide responses); §willingness to undergo TKA = willing if participant response was “probably willing” or “definitely willing”.