Skip to main content

Table 4 Comparison of case definitions (CD) for hospitalized respiratory infections (RI) according to their ability to capture pH1N1-positive cases

From: Lessons from a one-year hospital-based surveillance of acute respiratory infections in Berlin- comparing case definitions to monitor influenza

  Case definition Cases from entire study period Cases from study period 1
   Sensitivity Specificity Area under ROC
(95% CI)
Sensitivity Specificity Area under ROC
(95% CI)
Swabbing interval ≤ 4 days CD4 55% 59% 0.57
(0.45-0.69)
56% 63% 0.59
(0.42-0.77)
  CD2 95% 26% 0.60
(0.54-0.66)
100% 44% 0.72
(0.59-0.84)
  CD3 90% 41% 0.65
(0.57-0.73)
94% 44% 0.69
(0.55-0.83)
Swabbing interval ≤ 7 days CD4 55% 57% 0.56
(0.45-0.68)
56% 59% 0.57
(0.42-0.73)
  CD2 95% 22% 0.59
(0.53-0.64)
100% 38% 0.69
(0.60-0.78)
  CD3 90% 35% 0.63
(0.55-0.70)
94% 41% 0.68
(0.57-0.79)
  1. Sensitivity, specificity, area under the receiver operator curve (ROC), percentage of pH1N1-positives captured for study period 1 (significant influenza virus circulation in Berlin) and the entire study period (gold standard: PCR confirmation of pH1N1 infections)
  2. *Cases testing negative were only included as pH1N1-negative if the interval from symptom onset to swabbing was ≤ 4 days or ≤ 7 days, respectively. Highest ROC area in bold.