Table 1 Comparison of the demographic and clinical characteristics of all patients, and of those in the training and testing groups
Patient characteristics | Total (N = 492) | Testing (n = 148) | Training(n = 344) | P value |
|---|---|---|---|---|
Age (years), mean ± SD | 78.4 ± 9.8 | 78.0 ± 10.1 | 78.6 ± 9.7 | 0.511 |
Female sex, n (%) | 355 (72.2%) | 104 (70.3%) | 251 (73.0%) | 0.584 |
Body mass index (kg/m.2), mean ± SD | 22.3 ± 3.9 | 22.2 ± 4.1 | 22.4 ± 3.9 | 0.634 |
Charlson comorbidity index (CCI) score, n (%) | ||||
 - < 3 | 39 (7.9%) | 13 (8.8%) | 26 (7.6%) | 0.716 |
 - ≥ 3 | 453 (92.1%) | 135 (91.2%) | 318 (92.4%) |  |
Pre-injury ambulatory status, n (%) | ||||
 - Bedridden | 15 (3.0%) | 7 (4.7%) | 8 (2.3%) | 0.556 |
 - Indoor dependent | 43 (8.7%) | 10 (6.8%) | 33 (9.6%) |  |
 - Outdoor dependent | 16 (3.3%) | 5 (3.4%) | 11 (3.2%) |  |
 - Indoor independent | 145 (29.5%) | 45 (30.4%) | 100 (29.1%) |  |
Assistive device, n (%) | ||||
 - No ambulation | 15 (3.0%) | 7 (4.7%) | 8 (2.3%) | 0.839 |
 - Without assistive device | 259 (52.6%) | 76 (51.4%) | 183 (53.2%) |  |
 - Wheelchair | 10 (2.0%) | 2 (1.4%) | 8 (2.3%) |  |
 - Walker | 91 (18.5%) | 28 (18.9%) | 63 (18.3%) |  |
 - Quad cane | 3 (0.6%) | 1 (0.7%) | 2 (0.6%) |  |
 - Tripod cane | 27 (5.5%) | 9 (6.1%) | 18 (5.2%) |  |
 - Single cane | 27 (5.5%) | 25 (16.9%) | 62 (18.0%) |  |
Type of fracture, n (%) | ||||
 - Femoral neck fracture | 248 (50.4%) | 77 (52.0%) | 171 (49.7%) | 0.883 |
 - Intertrochanteric fracture | 241 (49.0%) | 70 (47.3%) | 171 (49.7%) |  |
 - Subtrochanteric fracture | 3 (0.6%) | 1 (0.7%) | 2 (0.6%) |  |
Treatment, n (%) | ||||
 - Conservative treatment | 32 (6.5%) | 11 (7.4%) | 21 (6.1%) | 0.791 |
 - Dynamic hip screw | 36 (7.3%) | 12 (8.1%) | 24 (7.0%) |  |
 - Cephalomedullary nailing | 202 (41.1%) | 56 (37.8%) | 146 (42.4%) |  |
 - Multiple screw fixation | 19 (3.9%) | 8 (5.4%) | 11 (3.2%) |  |
 - Hemiarthroplasty | 195 (39.6%) | 59 (39.9%) | 136 (39.5%) |  |
 - Total hip arthroplasty | 8 (1.6%) | 2 (1.4%) | 6 (1.7%) |  |
Comorbidities, n (%) | ||||
 - Chronic kidney disease stage 4 or severe | 130 (26.4%) | 37 (25.0%) | 93 (27.0%) | 0.658 |
 - Heart disease | 123 (25.0%) | 44 (29.7%) | 79 (23.0%) | 0.114 |
 - Cerebrovascular accident | 103 (20.9%) | 35 (23.6%) | 68 (19.8%) | 0.336 |
 - Lung disease | 34 (6.9%) | 13 (8.8%) | 21 (6.1%) | 0.332 |
 - Dementia | 81 (16.5%) | 16 (10.8%) | 65 (18.9%) | 0.033 |
Time to surgery n (%) | ||||
 - ≤ 48 h | 233 (50.7%) | 69 (50.4%) | 164 (50.8%) | 1.000 |
 - > 48 h | 227 (49.3%) | 68 (49.6%) | 159 (49.2%) |  |
Death, n (%) | 62 (12.6%) | 19 (12.8%) | 43 (12.5%) | 1.000 |