Summary of NP swab results compared with the modified gold standard among hospitalised adults with CAP
| Statistic | NP swab PCR detection* versus | |
| CAP all tests† (n=434) | CAP any tests‡ (n=1616) | |
| Sensitivity, % (95% CI) | 35.42 (25.92 to 45.84) | 34.17 (28.17 to 40.17) |
| Specificity, % (95% CI) | 99.41 (97.88 to 99.93) | 97.89 (97.13 to 98.65) |
| Positive likelihood ratio (95% CI) | 59.85 (14.64 to 244.67) | 16.21 (10.86 to 24.20) |
| Negative likelihood ratio (95% CI) | 0.65 (0.56 to 0.75) | 0.67 (0.61 to 0.74) |
| Pretest probability, % (95% CI) | 22.12 (18.30 to 26.32) | 14.85 (13.12 to 16.59) |
| Positive post-test probability, % (95% CI) | 94.37 (86.84 to 101.90) | 73.87 (65.70 to 82.05) |
| Negative post-test probability, % (95% CI) | 15.58 (12.02 to 19.15) | 10.50 (8.95 to 12.05) |
↵*Detection of Streptococcus pneumoniae in NP swabs was performed by real-time PCR targeting lytA and cpsA, and results were compared against modified gold standards in CAP cases where all† or any‡ of the following tests were performed: sputum culture, blood culture, pan-pneumococcal urine antigen detection (UADSpn) and/or a 13-valent pneumococcal conjugate vaccine serotype-specific UAD (UADPCV13).
CAP, community-acquired pneumonia; NP, nasopharyngeal; UAD, urine antigen detection.