Table 1.
Baseline subject characteristics
| Factor | mean ± SD or n (%) |
| Number of patients | 806 |
| Gender | |
| Male | 315 (39.1) |
| Female | 491 (60.9) |
| Age (yr) | 64.5 ± 8.5 |
| Race | |
| Asian | 18 (2.2) |
| Black/African American | 63 (7.8) |
| White | 617 (76.6) |
| Other | 94 (11.4) |
| Decline to state | 16 (1.9) |
| Body mass index | 33.81 ± 7.4 |
| Employed | 347 (43.1) |
| Median income by zip code | $66586 ± 25562 |
| Marital Status | |
| Single | 105 (13.0) |
| Married | 593 (73.6) |
| Widow/widower | 66 (8.2) |
| Divorced | 42 (5.2) |
| Patient lives alone (Y) | 99 (12.3) |
| Smoker | |
| Current | 68 (8.4) |
| Former | 232 (28.8) |
| Never | 506 (62.8) |
| Number of allergies | 1.5 ± 2.2 |
| Number of medications | 6.1 ± 4.8 |
| Pre-operative pain meds (Y) | 108 (13.4) |
| Simultaneous bilateral total knee arthroplasty | 37 (4.6) |
| Distance from hospital (miles) | 61.95 ± 122.8 |
| Day of surgery | |
| Monday | 242 (30.0) |
| Tuesday | 175 (21.7) |
| Wednesday | 129 (16.0) |
| Thursday | 194 (24.1) |
| Friday | 61 (7.6) |
| Saturday | 5 (0.6) |
| Holiday week surgery | 43 (5.3) |
| Surgery end time (h:min) | 11:05 ± 2:22 |