Table 3.
Patient characteristics and crude mortality rates (%) for each variable in the training and validation datasets.
| Training dataset (2007–2011) |
Validation dataset (2012) |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Alive (n = 330,711) |
Dead (n = 5722) |
Alive (n = 75,234) |
Dead (n = 1570) |
||||||||
| n | % | n | % | P | n | % | n | % | P | ||
| Gender | Male | 245,884 | 98.52 | 3701 | 1.48 | < 0.001 | 55,945 | 98.33 | 952 | 1.67 | < 0.001 |
| Female | 84,827 | 97.67 | 2021 | 2.33 | 19,289 | 96.90 | 618 | 3.10 | |||
| Diabetic | No | 272,427 | 98.43 | 4354 | 1.57 | < 0.001 | 60,847 | 98.13 | 1161 | 1.87 | < 0.001 |
| Yes (diet controlled, oral Rx, insulin) | 58,284 | 97.71 | 1368 | 2.29 | 14,387 | 97.24 | 409 | 2.76 | |||
| Urgency | Elective | 139,894 | 99.64 | 501 | 0.36 | < 0.001 | 27,220 | 99.68 | 88 | 0.32 | < 0.001 |
| Urgent | 118,416 | 98.75 | 1499 | 1.25 | 26,196 | 98.71 | 342 | 1.29 | |||
| Emergency | 71,834 | 95.22 | 3605 | 4.78 | 21,774 | 95.13 | 1115 | 4.87 | |||
| Salvage | 567 | 82.89 | 117 | 17.11 | 44 | 63.77 | 25 | 36.23 | |||
| Previous CABG | No | 303,359 | 98.27 | 5335 | 1.73 | < 0.001 | 69,169 | 97.91 | 1476 | 2.09 | 0.003 |
| Yes | 27,352 | 98.60 | 387 | 1.40 | 6065 | 98.47 | 94 | 1.53 | |||
| Previous MI | No | 247,273 | 98.32 | 4222 | 1.68 | 0.089 | 57,124 | 97.98 | 1179 | 2.02 | < 0.001 |
| Yes | 83,438 | 98.23 | 1500 | 1.77 | 18,110 | 97.89 | 391 | 2.11 | |||
| Previous PCI | No | 247,462 | 98.19 | 4568 | 1.81 | < 0.001 | 56,075 | 97.79 | 1270 | 2.21 | < 0.001 |
| Yes | 68,611 | 98.82 | 821 | 1.18 | 17,202 | 98.69 | 228 | 1.31 | |||
| Renal disease/dysfunction | None | 323,822 | 98.41 | 5231 | 1.59 | < 0.001 | 73,475 | 98.08 | 1439 | 1.92 | < 0.001 |
| Creatinine > 200 μmol/l | 4481 | 92.85 | 345 | 7.15 | 1177 | 93.12 | 87 | 6.88 | |||
| Dialysis | 2408 | 94.28 | 146 | 5.72 | 582 | 92.97 | 44 | 7.03 | |||
| Indication | Stable | 142,330 | 99.59 | 587 | 0.41 | < 0.001 | 27,383 | 99.67 | 90 | 0.33 | < 0.001 |
| Acute, not primary | 124,665 | 98.53 | 1861 | 1.47 | 27,727 | 98.39 | 453 | 1.61 | |||
| Acute, primary | 62,870 | 95.15 | 3208 | 4.85 | 19,929 | 95.17 | 1011 | 4.83 | |||
| Other | 846 | 92.76 | 66 | 7.24 | 195 | 92.42 | 16 | 7.58 | |||
| History of cerebrovascular event | No | 318,867 | 98.39 | 5234 | 1.61 | < 0.001 | 72,326 | 98.07 | 1423 | 1.93 | < 0.001 |
| Yes | 11,844 | 96.04 | 488 | 3.96 | 2908 | 95.19 | 147 | 4.81 | |||
| Cardiogenic shock | No | 327,392 | 98.69 | 4345 | 1.31 | < 0.001 | 74,372 | 98.45 | 1171 | 1.55 | < 0.001 |
| Yes | 3319 | 70.68 | 1377 | 29.32 | 862 | 68.36 | 399 | 31.64 | |||
| Age | Mean age at procedure | 64.6 (95% CI 64.6 to 64.7) | 73.3 (95% CI 73.0 to 73.6) | < 0.001 | 64.9 (95% CI 64.8 to 64.9) | 74.3 (95% CI 73.7 to 74.8) | < 0.001 | ||||
| Median age at procedure | 64.9 (IQR 17) | 75 (IQR 16) | 65 (IQR 18) | 76 (IQR 16) | |||||||
P values indicate results of statistical comparisons within datasets of patients recorded alive vs dead at 30 days (Chi squared test for categorical variables, t test for age).