Table 3.
Comparison of model and validation set. The prediction model is created using the development data set. The total data set was split via random assignment to either the development or validation data set. The groups are generally similar.
| All | Missing Data | Development Set | Validation Set | p-value | |
|---|---|---|---|---|---|
| N = 16043 (% of present data) | N (% of total) | N = 8039; 50.1% | N = 8004; 49.9% | ||
| Age [years; mean ± SD] | 71.2 ± 9.3 | 0 (0) | |||
| Female | 6425 (40) | 0 (0) | 3194 (20) | 3231 (20) | 0.411 |
| Race | 793 (5) | 0.605 | |||
| – White | 14217 (89) | 7098 (88) | 7119 (94) | ||
| – Black | 681 (4) | 354 (4) | 327 (4) | ||
| – Asian | 277 (2) | 146 (2) | 131 (2) | ||
| – Other | 75 (1) | 28 (0) | 37 (0) | ||
| Asymptomatic Neurologic Symptom Status* | 4064 (66) | 9898 (62) | 2024 (66) | 2040 (67) | 0.518 |
| Physiologic High Risk* | 254 (4) | 9848 (61) | 124 (4) | 130 (4) | 0.654 |
| Anatomic High Risk* | 698 (11) | 9842 (61) | 333 (11) | 365 (12) | 0.148 |
| Congestive Heart Failure | 143 (1) | 0 (0) | 78 (55) | 65 (46) | 0.314 |
| Diabetes Mellitus | 4839 (30) | 0 (0) | 2331 (29) | 2508 (31) | 0.001 |
| Smoker | 4535 (28) | 0 (0) | 2296 (29) | 2239 (28) | 0.41 |
| Dependent Functional Status | 417 (3) | 66 (0) | 206 (3) | 211 (3) | 0.804 |
| Dyspnea | 2420 (15) | 0 (0) | 1228 (15) | 1192 (15) | 0.508 |
| Chronic Obstructive Pulmonary Disease | 1808 (11) | 0 (0) | 917 (11) | 891 (11) | 0.583 |
| Hemodialysis Dependence | 153 (1) | 0 (0) | 79 (1) | 74 (1) | 0.745 |
| Preoperative Open Wound | 149 (1) | 0 (0) | 81 (1) | 68 (1) | 0.323 |
| Chronic Steroid Use | 481 (3) | 0 (0) | 251 (3) | 230 (3) | 0.379 |
| Bleeding Disorder | 3275 (20) | 0 (0) | 1625 (20) | 1650 (21) | 0.531 |
| Preoperative > Transfusion 4 units | 28 (0) | 0 (0) | 16 (0) | 12 (0) | 0.571 |
| ASA Class | 0 (0) | 0.779 | |||
| – I | 20 (0) | 10 (0) | 10 (0) | ||
| – II | 1019 (6) | 516 (6) | 503 (6) | ||
| – III | 12575 (78) | 6309 (79) | 6266 (78) | ||
| – IV | 2418 (15) | 1200 (15) | 1218 (15) | ||
| – V | 2 (0) | 0 (0) | 2 (0) | ||
| – None | 9 (0) | 4 (0) | 0 (0) | ||
| Preoperative Antiplatelet Agent* | 5649 (35) | 9797 (61) | 2825 (90) | 2824 (91) | 0.389 |
| Preoperative Statin* | 5014 (80) | 9792 (61) | 2507 (80) | 2507 (80) | 0.612 |
| Preoperative Beta Blocker* | 3474 (34) | 9819 (61) | 1718 (55) | 1756 (57) | 0.16 |
| BMI > 30 kg/m2 | 5374 (34) | 71 (0) | 2693 (33) | 2681 (33) | 0.987 |
| Hematocrit [mean ± SD] | 39.7 ± 4.7 | 595 (4) | 39.7 ± 4.7 | 39.7 ± 4.7 | 0.97 |
| Hematocrit < 30 | 399 (3) | 595 (4) | 209 (3) | 190 (3) | 0.389 |
| Serum Creatinine > 1.2 g/dL | 3930 (25) | 592 (4) | 1900 (25) | 2030 (26) | 0.007 |