TABLE 2.
SUMMARY OF THE QUALITY OF THE RESULTS OF ORTHOGONAL PARTIAL LEAST SQUARES DISCRIMINANT ANALYSIS MODELS FOR ALL SERUM SAMPLES OF DIAGNOSTIC GROUPS AND SPECIFIC AGE GROUPS
| |
|
Quality Results OPLS-DA |
||||||
|---|---|---|---|---|---|---|---|---|
| OPLS-DA Models | Samples | R2Y | Q2 | P Value | Sensitivity : Specificity | PPV:NPV | ACC | AUROC |
| SIRS/ICU control subjects vs. healthy control subjects |
All |
0.74 |
0.60 |
1.56 × 10−13 |
0.90 ± 0.10 : 0.95 ± 0.07 |
0.95:0.90 |
0.92 |
0.95 |
| |
Infants |
0.72 |
0.62 |
2.2 × 10−5 |
0.92 ± 0.14 : 0.92 ± 0.16 |
0.92:0.92 |
0.92 |
0.97 |
| |
Toddlers |
0.87 |
0.69 |
7.2 × 10−7 |
0.94 ± 0.12 : 0.88 ± 0.15 |
0.88:0.94 |
0.91 |
0.98 |
| |
School age |
0.41 |
0.29 |
0.087 |
0.75 ± 0.30 : 0.78 ± 0.27 |
0.75:0.78 |
0.77 |
0.85 |
| Septic shock vs. healthy control subjects |
All |
0.83 |
0.68 |
4.82 × 10−20 |
0.90 ± 0.08 : 0.97 ± 0.05 |
0.98:0.86 |
0.93 |
0.98 |
| |
Infants |
0.92 |
0.78 |
2.15 × 10−7 |
0.95 ± 0.09 : 1.0 |
1.0:0.92 |
0.97 |
1.0 |
| |
Toddlers |
0.92 |
0.75 |
1.5 × 10−7 |
0.90 ± 0.14 : 1.0 |
1.0:0.90 |
0.94 |
0.99 |
| |
School age |
0.65 |
0.61 |
1.3 × 10−4 |
0.92 ± 0.14 : 0.89 ± 0.2 |
0.92:0.89 |
0.91 |
0.98 |
| Septic shock vs. SIRS/ICU control subjects |
All |
0.46 |
0.28 |
4.5 × 10−6 |
0.78 ± 0.11 : 0.72 ± 0.14 |
0.80:0.68 |
0.75 |
0.82 |
| |
Infants |
0.50 |
0.41 |
2.9 × 10−4 |
0.91 ± 0.13 : 0.62 ± 0.26 |
0.79:0.80 |
0.79 |
0.88 |
| |
Toddlers |
0.53 |
0.30 |
0.026 |
0.63 ± 0.22 : 0.69 ± 0.23 |
0.71:0.61 |
0.66 |
0.82 |
| School age | 0.63 | 0.52 | 0.0013 | 0.92 ± 0.14 : 0.88 ± 0.23 | 0.92:0.88 | 0.91 | 0.94 | |
Definition of abbreviations: ACC = accuracy; AUROC = area under a receiver operator curve; ICU = intensive care unit; NPV = negative predictive value; OPLS-DA = orthogonal partial least squares discriminant analysis; PPV = positive predictive value; SIRS = systemic inflammatory response syndrome.
R2Y metric describes the percentage of variation explained by the model; Q2 metric describes the predictive ability of the model. The difference between R2Y and Q2 indicates the model’s goodness of fit. Sensitivity, specificity, PPV, NPV, and ACC were calculated based on the predictive values of Y-variables obtained in a sevenfold cross-validation step during OPLS-DA model construction. Sensitivity and specificity are reported with 95% confidence intervals. The AUROC statistic provides additional interpretation of discriminatory power of the models.