Table 2.
Fivefold cross-validation for predictive equations developed from same patients in the acute phase (n = 168) and late phase (n = 168).
| A | ||||
|---|---|---|---|---|
| Acute phase (<5 days) | ||||
| Test set | Developed predictive equations | R2 | RMSE | SEE |
| 1 | REE = 1686.9Ht + 30.7VeMax + 8.0Wt - 1975.8 | 0.401 | 292.5 | 344.6 |
| 2 | REE = 1627.8Ht + 25.3VeMax + 8.4Wt – 1830.3a | 0.414 | 294.0 | 343.7 |
| 3 | REE = 2048.8Ht + 115.7TMax + 7.1Wt – 6462.8 | 0.442 | 408.6 | 318.8 |
| 4 | REE = 1542.8Ht + 23.4VeMax + 7.5Wt – 1629.1 | 0.395 | 381.9 | 322.4 |
| 5 | REE = 1740.4Ht + 50.2PEEP + 34.6Ve – 1876.1 | 0.391 | 426.3 | 317.1 |
| B | ||||
|---|---|---|---|---|
| Late phase (≥ 6 Days) | ||||
| Test set | Developed predictive equations | R2 | RMSE | SEE |
| 1 | REE = 919.1 + 12.0Wt + 43.1VeMax -7.9Age | 0.491 | 412.4 | 328.5 |
| 2 | REE = 1008.3 + 14.4Wt + 26.1VeMax– 7.9Agea | 0.498 | 423.6 | 335.9 |
| 3 | REE = 1143.3Ht + 11.2Wt – 8.9Age – 318.4 | 0.432 | 380.5 | 346.0 |
| 4 | REE = 1244.6Ht + 10.6Wt – 6.9Age – 556.3 | 0.398 | 301.7 | 364.5 |
| 5 | REE = 1445.3Ht + 9.3Wt + 27.6VeMax -1522.7 | 0.363 | 395.3 | 344.4 |
Acute phase, ≤5 days; HR heart rate (beats/min); Ht, Height (m); late phase, ≥6 days, PEEP positive end-expiratory pressure; R2, coefficient of determination, REE resting energy expenditure, RMSE root mean square error, SEE standard error of the estimate, TMax maximum body temperature in the previous 24 h (°C), VeMax maximum minute ventilation in the previous 24 h (L/min), Wt weight (kg).
Multiple linear regression analysis was applied.
A stepwise method of variable selection applied. Model assumptions fulfilled.
No interactions between independent variables. No multicollinearity detected.
aThe selected equation.