Table 3. Likelihood ratios and ROC-areas of combinations of multiple red traffic lights.
| BLEEKER et al.[23] | BRENT et al.[18] | OOSTENBRINK et al.[22] | ROUKEMA et al.[20] | THOMPSON et al.[21] | MONTENY et al.[19] | VAN DEN BRUEL et al.[4] | ||
| Ntotal = 595 SI = 137;23.0% | Ntotal = 494 SI = 46;9.3% | Ntotal = 423 SI = 170;40.2% | Ntotal = 1,459 SI = 171;11.7% | Ntotal = 434 SI = 161;37.1% | Ntotal = 487 SI = 20;4.1% | Ntotal = 2,368 SI = 28;1.2% | ||
| Number red features | LR +/- (CI) | |||||||
| ≥1 RTL | Likelihood ratio + | 1.18 (1.10–1.27)* | 1.94 (1.57–2.39)* | 1.39 (1.27–1.51)* | 1.75 (1.39–2.20)* | 1.28 (1.12–1.46)* | 1.08 (1.05–1.12) | 3.33 (2.76–4.02)* |
| Likelihood ratio - | 0.41 (0.24–0.70) | 0.42 (0.26–0.69) | 0.13 (0.06–0.28) | 0.81 (0.72–0.91) | 0.59 (0.43–0.80) | - | 0.24 (0.12–0.53) | |
| ≥2 RTLs | Likelihood ratio + | 1.49 (1.25–1.79)* | 3.70 (2.68–5.12)* | 2.36 (1.94–2.87)* | 3.40 (2.24–5.16)* | 1.75 (1.31–2.33)* | 1.25 (1.07–1.46) | 6.38 (4.82–8.44)* |
| Likelihood ratio - | 0.68 (0.55–0.84) | 0.49 (0.35–0.69) | 0.35 (0.26–0.46) | 0.88 (0.82–0.94) | 0.78 (0.67–0.89) | 0.36 (0.10–1.35) | 0.36 (0.21–0.62) | |
| ≥3 RTLs | Likelihood ratio + | 2.10 (1.50–2.93)* | 3.90 (2.15–7.08) | 4.65 (3.29–6.58)* | 4.14 (2.02–8.50) | 2.97 (1.66–5.31)* | 1.44 (1.07–1.95) | 10.0 (6.43–15.45)* |
| Likelihood ratio - | 0.81 (0.72–0.91) | 0.79 (0.67–0.94) | 0.47 (0.39–0.57) | 0.95 (0.91–1.00) | 0.88 (0.81–0.95) | 0.58 (0.30–1.15) | 0.56 (0.40–0.79) | |
| Sens/Spec (CI) | ||||||||
| ≥1 RTL | Sensitivity | 0.91 (0.84-0.94) | 0.74 (0.60-0.84) | 0.96 (0.92-0.98) | 0.36 (0.29-0.43) | 0.76 (0.69-0.82) | 1.00 (0.84-1.00) | 0.82 (0.64-0.92) |
| Specificity | 0.23 (0.20-0.27) | 0.62 (0.57-0.66) | 0.31 (0.25-0.37) | 0.80 (0.77-0.82) | 0.40 (0.35-0.46) | 0.07 (0.05-0.10) | 0.75 (0.74-0.77) | |
| ≥2 RTLs | Sensitivity | 0.58 (0.50-0.66) | 0.59 (0.44-0.72) | 0.76 (0.70-0.82) | 0.16 (0.12-0.23) | 0.40 (0.33-0.48) | 0.90 (0.70-0.97) | 0.68 (0.49-0.82) |
| Specificity | 0.61 (0.56-0.65) | 0.84 (0.81-0.87) | 0.68 (0.62-0.73) | 0.95 (0.94-0.96) | 0.77 (0.72-0.82) | 0.28 (0.24-0.32) | 0.89 (0.88-0.91) | |
| ≥3 RTLs | Sensitivity | 0.31 (0.24-0.39) | 0.26 (0.16-0.40) | 0.59 (0.51-0.66) | 0.06 (0.03-0.11) | 0.17 (0.12-0.24) | 0.70 (0.48-0.85) | 0.46 (0.30-0.64) |
| Specificity | 0.85 (0.82-0.88) | 0.93 (0.91-0.95) | 0.87 (0.83-0.91) | 0.98 (0.98-0.99) | 0.94 (0.91-0.96) | 0.51 (0.47-0.56) | 0.95 (0.94-0.96) | |
| ROC-area (CI) | ||||||||
| All red features | 0.64 (0.59–0.70) | 0.73 (0.65–0.82) | 0.79 (0.74–0.84) | 0.59 (0.54–0.63) | 0.63 (0.57–0.68) | 0.65 (0.53–0.77) | 0.84 (0.75–0.93) | |
| General# | 0.64 (0.59–0.70) | 0.73 (0.65–0.81) | 0.69 (0.64–0.75) | 0.59 (0.54–0.64) | 0.60 (0.55–0.66) | 0.65 (0.54–0.76) | 0.82 (0.72–0.91) | |
| Disease spec.∧ | 0.51 (0.46–0.57) | 0.56 (0.47–0.66) | 0.77 (0.72–0.81) | 0.53 (0.48–0.58) | 0.56 (0.50–0.62) | 0.56 (0.43–0.69) | 0.69 (0.57–0.81) | |
*P-value <0.05 (added value of e.g. ≥3 RTLs above ≥2 RTLs, by logistic regression analysis).
LR: likelihood ratio (positive and negative).
Sens: sensitiviteit; Spec: specificiteit; CI: confidence interval.
#
1. Colour: pale / mottled/ ashen/ blue; 2. No response to social cues; 3. Ill appearance; 4. Does not (stay) awake; 5. Weak/ high pitched/ continuous cry; 6. Grunting; 7. Tachypnoea; 9. Reduced skin turgor; 10. Age <3 m & temp ≥38°C;
∧
8. Chest indrawing 11. Non-blanching rash; 12. Bulging fontanelle; 13. Neck stiffness; 14. Status epilepticus; 15. Focal neurologic symptoms; 16. Focal seizures.