Table 3

 Sensitivity and specificity of cumulative anti-P aeruginosa antibody scores according to the method by which material was obtained for microbiological culture

Sputum onlyAll (sputum + swab)Swab only
PPV, positive predictive value; NPV, negative predictive value.
Predictive values were calculated for the given prevalence—that is, 61.5% for all patients (115/183), 85.5% for patients with sputum cultures (65/76), and 45.0% for patients with swabs (50/107).
Number of subjects (n)76183107
Sensitivity % (95% CI)95.4 (87.1 to 99.0)86.1 (78.4 to 91.8)74.0 (59.7 to 85.4)
(n/N)62/6599/11537/50
Specificity % (95% CI)100 (71.5 to 100)95.6 (87.6 to 99.1)94.7 (85.4 to 98.9)
(n/N)11/1165/6854/57
PPV % (95% CI)100 (94.2 to 100)97.1 (91.6 to 99.4)92.5 (79.6 to 98.4)
NPV % (95% CI)78.6 (49.2 to 95.3)80.2 (69.9 to 88.3)80.6 (69.1 to 89.2)