TABLE 2.

Diagnostic accuracies of combined nose-throat swabs and nasopharyngeal aspirates according to patient characteristics

CharacteristicNo. positive (n = 115)Combined nasal-throat swabs Nasopharyngeal aspirates
No. identifiedSensitivity (95% confidence interval)Negative predictive value (95% confidence interval)No. identifiedSensitivity (95% confidence interval)Negative predictive value (95% confidence interval)
Age group, yr
    0-1424241001002188 (74-100)88 (74-100)
    15-24232296 (87-100)95 (87-100)2087 (73-100)88 (74-100)
    25-44353497 (92-100)97 (90-100)3189 (78-99)88 (77-99)
    ≥45332988 (77-99)95 (91-100)2679 (65-93)92 (86-98)
Male555091 (83-99)94 (89-99)4887 (78-96)92 (86-98)
Female605998 (95-100)a 99 (96-100)5083 (74-93)87 (80-95)
Pregnancy111001001100100
Clinical presentation
    Influenza-like illness888495 (91-100)95 (89-100)7990 (83-96)89 (82-96)
    Pneumonia7571 (38-100)95 (89-100)571 (38-100)95 (89-100)
Admitted to hospital201785 (69-100)96 (91-100)1785 (69-100)96 (91-100)
Total11510995 (91-99)b 96 (93-99)9885 (79-92)90 (85-94)
  • a P = 0.01 for the comparison of combined nasal-throat swabs with nasopharyngeal aspirates.

  • b P = 0.02 for the comparison of combined nasal-throat swabs with nasopharyngeal aspirates.