Table 1.
Sensitivity, Specificity, and Diagnostic Odds Ratio of Polymerase Chain Reaction (PCR) Test According to PCR Technique
| Sample | Sensitivity (95% CI) |
Specificity (95% CI) |
DOR (95% CI) |
LR+ (95% CI) |
LR− (95% CI) |
|---|---|---|---|---|---|
| BALF samples | |||||
| qPCR (n = 2673) | 0.987 (.968–.995) |
0.893 (.844–.927) |
635 (269–1498) |
9.194 (5.727–12.661) |
0.014 (.001–.027) |
| cPCR (n = 2254) | 0.972 (.932–.988) |
0.954 (.930–.970) |
710 (305–1652) |
21.178 (12.438–29.918) |
0.30 (.004–.056) |
| IS samples | |||||
| qPCR (n = 491) | 0.980 (.944–.993) |
0.815 (.721–.883) |
217 (78–601) |
5.303 (3.024–7.583) |
0.024 (.000–.049) |
| cPCR (n = 590) | 0.956 (.887–.984) |
0.917 (.866–.950) |
243 (90–656) |
11.511 (5.985–17.036) |
0.047 (.001–.094) |
| URT samples | |||||
| qPCR (n = 352) | 0.892 (.710–.965) |
0.905 (.809–.955) |
78 (26–238) |
9.340 (2.997–15.682) |
0.120 (NE–.245) |
| cPCR (n = 512) | 0.787 (.502–.931) |
0.960 (.911–.982) |
87 (27–284) |
19.424 (5.358–33.490) |
0.222 (NE–.446) |
Sensitivity, specificity, DORs, and positive and negative likelihood ratios with 95% CI calculated from the coefficients of the binomial regression model. In regard to human immunodeficiency virus (HIV) versus non-HIV status, there was no significant difference in the cohorts of patients tested by cPCR or qPCR or by specimen types tested. Numbers of samples (n) where analysis of sensitivity/specificity was performed by sample type are shown. “NE” (not evaluable) appears when the corresponding results obtained by the calculating algorithm had a negative sign, which is impossible as the LRs are ratios between 2 positive numbers (proportions). This fact is due to the use of an approximate method to calculate the 95% CIs of the LRs, the “delta method.”
Abbreviations: BALF, bronchoalveolar lavage fluid; CI, confidence interval; cPCR, conventional polymerase chain reaction; DOR, diagnostic odds ratio; IS, induced sputum; LR+, positive likelihood ratio; LR–, negative likelihood ratio; NE, not evaluable; qPCR, quantitative polymerase chain reaction; URT, upper respiratory tract.