Accuracy of BLUE protocol
| Mechanism of dyspnoea | BLUE protocol profile | Sensitivity | Specificity | Positive predictive value | Negative predictive value |
| Acute haemodynamic pulmonary oedema | B-profile | 97% | 95% | 87% | 99% |
| Exacerbated COPD or severe acute asthma | Nude profile (A-profile with no DVT and no PLAPS) | 89% | 97% | 93% | 95% |
| Pulmonary embolism | A-profile with DVT | 81% | 99% | 94% | 98% |
| Pneumothorax | A′-profile (with lung point) | 88% | 100% | 100% | 99% |
| Pneumonia | All profiles# | 89% | 94% | 88% | 95% |
| B′-profile | 11% | 100% | 100% | 70% | |
| A/B-profile | 14.5% | 100% | 100% | 71.5% | |
| C-profile | 21.5% | 99% | 90% | 73% | |
| A-V-PLAPS profile | 42% | 96% | 83% | 78% |
COPD: chronic obstructive pulmonary disease; DVT: deep venous thrombosis. #: sensitivity calculated by adding the sensitivity of each of the four profiles. Reproduced and modified from [7] with permission from the publisher.