Table 3 2 × 2 contingency table detailing the sensitivity and specificity analyses for the CDQ cut off score of 16.5 for ‘existing’ cases of COPD
From: Accuracy of the COPD diagnostic questionnaire as a screening tool in primary care
| Â | True class (COPD diagnosis with presence of obstruction confirmed by spirometry) | ||
|---|---|---|---|
True | False | Total | |
Predicted class (Score ≥ 16.5) | |||
 True | 20 (66.7%) | 4 (13.3%) | 24 (80.0%) |
 False | 4 (13.3%) | 2 (6.7%) | 6 (20.0%) |
Total | 24 (80.0%) | 6 (20.0%) | 30 (100.0%) |