Table 1.
Baseline Characteristics of Study Participants, by APU Status
| Characteristics | Patients With No APU (N=450) |
Patients With APU (N=208) |
All Patients (N=658) |
P Value* |
|---|---|---|---|---|
| N (%) or mean (SD) | ||||
| Mean age (yrs) | 83.1 (6.7) | 83.4 (6.5) | 83.2 (6.6) | .66 |
| Age ≥ 85 yrs | 208 (46.2%) | 98 (47.1%) | 306 (46.5%) | .83 |
| Male sex | 102 (22.7%) | 50 (24.0%) | 152 (23.1%) | .70 |
| White race | 441 (98.0%) | 204 (98.1%) | 645 (98.0%) | .95 |
| Community resident before admission | 316 (70.2%) | 133 (63.9%) | 449 (68.2%) | .11 |
| Trochanteric fracture | 202 (44.9%) | 93 (44.7%) | 295 (44.8%) | .97 |
| Partial or total arthroplasty | 152 (33.8%) | 82 (39.4%) | 234 (35.6%) | .16 |
| Mean Rand Sickness at Admission score | 11.7 (5.5) | 13.5 (6.9) | 12.3 (6.0) | <.001 |
| Mean Charlson Comorbidity Index | 1.2 (1.5) | 1.6 (1.4) | 1.3 (1.5) | .02 |
| Albumin < 3.0 g/dL | 138 (30.7%) | 69 (33.2%) | 207 (31.5%) | .52 |
| Mean MMSE score | 19.5 (10.5) | 16.0 (11.2) | 18.4 (10.9) | <.001 |
| History of chronic cognitive deficit | 112 (24.9%) | 83 (39.9%) | 195 (29.6%) | <.001 |
| Mean BMI (weight [kg]/height [m]2) | 24.0 (4.9) | 23.4 (5.4) | 23.8 (5.1) | .17 |
| High nutritional risk | 25 (5.6%) | 33 (16.3%) | 58 (9.0%) | <.001 |
| Incontinence | .004 | |||
| None | 331 (73.9%) | 127 (61.4%) | 458 (69.9%) | |
| Urinary only | 74 (16.5%) | 46 (22.2%) | 120 (18.3%) | |
| Fecal with or without urinary | 43 (9.6%) | 34 (16.4%) | 77 (11.8%) | |
| Activity level | <.001 | |||
| Walks | 79 (17.6%) | 19 (9.2%) | 98 (15.0%) | |
| Bedbound | 176 (39.3%) | 116 (56.0%) | 292 (44.6%) | |
| Chairbound | 193 (43.1%) | 72 (34.8%) | 265 (40.5%) | |
| Arterial insufficiency | 166 (36.9%) | 88 (42.3%) | 254 (38.6%) | .18 |
| Pre-existing pressure ulcers | 11 (2.4%) | 8 (3.9%) | 19 (2.9%) | .32 |
| Mean length of hospital stay (days) | 5.6 (2.8) | 6.6 (3.8) | 5.9 (3.2) | <.001 |
| Mean interval between initial hospital admission and baseline assessment (days) | 2.9 (2.0) | 2.8 (2.1) | 2.9 (2.0) | .56 |
| Baseline assessment before day of surgery | 37 (8.2%) | 40 (19.2%) | 77 (11.7%) | <.001 |
Notes: Number of missing values: BMI=20; incontinence=3; nutritional risk=13; activity level=3. All other variables had no missing values.
APU=acquired pressure ulcer; SD=standard deviation; MMSE=Mini-Mental State Exam; BMI=body mass index
*
P values are derived from chi-square, Fisher’s exact, or t-tests, as appropriate, comparing patients with and without APUs.