Table 1.
Dataset description for Model development, internal and external validation.
| Dataset | COVID-19 | Non-COVID | Total | |
|---|---|---|---|---|
| aTraining (80% of OSR) | Italy (OSR) | 629 | 670 | 1299 |
| aBalanced Training Set | 670 | 670 | 1340 | |
| aInternal validation (20% of OSR) | 157 | 168 | 325 | |
| External validation | Italy-1 | 163 | 174 | 337 |
| Italy-2 | 104 | 145 | 249 | |
| Italy-3 | 118 | 106 | 224 | |
| Brazil-1 | 352 | 949 | 1301 | |
| Brazil-2 | 334 | 11 | 345 | |
| Ethiopia | 200 | – | 200 |
a
Five-fold cross validation was used for performance evaluation. Number of samples per fold for training, augmented training, and internal validation is reported here.