One hundred forty-six true laboratory-confirmed influenza cases were identified (Fig. 1 ). By including records with a flu diagnosis or a positive flu lab result (excluding records with a negative flu lab), the sensitivity of the HIE was 90% and the PPV was 94%. In comparison, the sensitivity of NC reporting was 91%. HIE cases were detected a median of 5 days after admission versus 2 days through the NC system. Data for influenza hospitalizations from the HIE did not differ signifi-cantly from data collected through the NC system with regard to sex, age, pregnancy status and mortality. The time series of influenza-related hospital admissions from the HIE and NC system were highly correlated (r 00.99).