Table 4 Diagnostic performance of sputum Gram stain in patients with CAP and HCAP
| Â | CAP | HCAP | p value |
|---|---|---|---|
n = 328 | n = 342 | ||
No sputum sample, n (%) | 55 (16.8) | 24 (7.0) | <0.001 |
Poor quality sample, n (%) | 43 (13.1) | 70 (20.5) | 0.011 |
Good quality sample, n (%) | 230 (70.1) | 248 (72.5) | 0.49 |
No meaningful microorganism, n (%) | 30 (9.1) | 27 (7.9) | 0.56 |
Polymicrobial flora, n (%) | 56 (17.1) | 94 (27.5) | 0.001 |
Predominant morphotype, n (%) | 144 (43.9) | 127 (37.1) | 0.0744 |
Positive predict, n (%) | 107 (32.6) | 82 (24.0) | 0.013 |
Sensitivity (%) | Â | Â | Â |
Streptococcus pneumoniae | 63.1 | 61.7 | |
Haemophilus influenzae | 76.8 | 44.4 | |
Moraxella catarrhalis | 85.0 | 54.2 | |
Klebsiella pneumoniae | 50.0 | 37.5 | |
Pseudomonas aeruginosa | 20.0 | 23.5 | |
Staphylococcus aureus | 50.0 | 0 | |
Specificity (%) | Â | Â | Â |
Streptococcus pneumoniae | 89.7 | 93.0 | |
Haemophilus influenzae | 94.8 | 95.3 | |
Moraxella catarrhalis | 97.6 | 92.4 | |
Klebsiella pneumoniae | 98.7 | 99.5 | |
Pseudomonas aeruginosa | 100 | 99.6 | |
Staphylococcus aureus | 100 | Â |