Table 4. Diagnostic accuracy of the REACH used in the derivation set (N=1,129).
| Diagnostic criteria | AD prevalence (%) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) | ER (%) | Youden's index (%) |
|---|---|---|---|---|---|---|---|
| Eczema on the antecubital/popliteal fossae | |||||||
| 2M | 12.0 | 73.7 | 97.5 | 82.4 | 96.0 | 5.7 | 71.2 |
| 2M+1m | 11.7 | 72.4 | 97.7 | 83.3 | 95.8 | 5.7 | 70.1 |
| 2M+2m | 10.8 | 67.8 | 98.1 | 84.4 | 95.1 | 6.0 | 65.8 |
| 2M+3m | 8.9 | 59.2 | 98.9 | 89.1 | 94.0 | 6.5 | 58.1 |
| 2M+4m | 6.2 | 43.4 | 99.6 | 94.3 | 91.9 | 8.0 | 43.0 |
| 2M+5m | 3.9 | 27.6 | 99.8 | 95.5 | 89.9 | 9.9 | 27.4 |
| Eczema on the non-antecubital/popliteal fossae | |||||||
| 1M | 20.1 | 88.2 | 90.5 | 59.0 | 98.0 | 9.8 | 78.6 |
| 1M+1m | 18.6 | 86.8 | 92.0 | 62.9 | 97.8 | 8.7 | 78.9 |
| 1M+2m | 15.8 | 80.9 | 94.4 | 69.1 | 97.0 | 7.4 | 75.3 |
| 1M+3m | 11.8 | 70.4 | 97.3 | 80.5 | 95.5 | 6.3 | 67.7 |
| 1M+4m | 7.5 | 50.0 | 99.1 | 89.4 | 92.7 | 7.5 | 49.1 |
| 1M+5m | 4.4 | 30.9 | 99.7 | 94.0 | 90.3 | 9.6 | 30.6 |
| Combinations | |||||||
| 2M OR 1M+1m | 19.0 | 88.2 | 91.8 | 62.6 | 98.0 | 8.7 | 80.0 |
| 2M OR 1M+2m | 17.0 | 86.8 | 93.9 | 68.8 | 97.9 | 7.1 | 80.7 |
| 2M OR 1M+3m | 14.9 | 84.9 | 96.0 | 76.8 | 97.6 | 5.5 | 80.9 |
| 2M OR 1M+4m* | 13.4 | 80.3 | 97.0 | 80.8 | 96.9 | 5.2 | 77.3 |
| 2M OR 1M+5m | 12.6 | 77.0 | 97.4 | 82.4 | 96.5 | 5.3 | 74.4 |
| 2M+1m OR 1M+2m | 16.7 | 85.5 | 94.1 | 69.1 | 97.7 | 7.1 | 79.6 |
| 2M+1m OR 1M+3m | 14.5 | 83.6 | 96.2 | 77.4 | 97.4 | 5.5 | 79.8 |
| 2M+1m OR 1M+4m | 13.0 | 78.9 | 97.2 | 81.6 | 96.7 | 5.2 | 76.2 |
| 2M+1m OR 1M+5m | 12.2 | 75.7 | 97.6 | 83.3 | 96.3 | 5.3 | 73.3 |
| 2M+2m OR 1M+3m | 13.6 | 78.9 | 96.5 | 77.9 | 96.7 | 5.8 | 75.5 |
| 2M+2m OR 1M+4m | 12.1 | 74.3 | 97.5 | 82.5 | 96.1 | 5.6 | 71.9 |
| 2M+2m OR 1M+5m | 11.3 | 71.1 | 98.0 | 84.4 | 95.6 | 5.7 | 69.0 |
| 2M+3m OR 1M+4m | 10.3 | 65.8 | 98.4 | 86.2 | 94.9 | 6.0 | 64.2 |
| 2M+3m OR 1M+5m | 9.5 | 62.5 | 98.8 | 88.8 | 94.4 | 6.1 | 61.3 |
| 2M+4m OR 1M+5m | 6.7 | 46.7 | 99.5 | 93.4 | 92.3 | 7.6 | 46.2 |
| ISAAC | 15.1 | 73.0 | 94.0 | 65.3 | 95.7 | 8.9 | 67.0 |
| Standard AD prevalence | 13.5 |
*2M means recurrent eczema on the antecubital or/and popliteal fossae, and 1M means recurrent eczema on the other locations except the antecubital/popliteal fossae.
AD, atopic dermatitis; PPV, positive predictive value; NPV, negative predictive value; ER, error rate; M, major criteria; m, minor criteria.