title: An evaluation of influenza mortality surveillance, 1962-1979. II. Percentage of pneumonia and influenza deaths as an indicator of influenza activity.
abstract: In this paper, the percentage of all deaths that are related to pneumonia and influenza (P & I ratio) is evaluated as an indicator of influenza activity and as a method to quantify the impact of influenza on mortality. Analysis of data from 1962-1979 indicates that the P & I ratio is an accurate indicator of influenza activity, as confirmed by independent systems of morbidity and laboratory surveillance. A rule using the P & I ratio for detecting an outbreak of an influenza epidemic was evaluated. It was found to be much more specific than a rule based on the regression model, but did not provide more timely detection of outbreaks of influenza during the past 17 years. The use of the P & I ratio in the autoregressive integrated moving average (ARIMA) model of forecasting provided the most accurate prediction of the expected pneumonia and influenza mortality.
mesh_terms: D002487:Centers for Disease Control and Prevention, U.S.; D005544:Forecasting / Q000379:methods*; D006801:Humans; D007251:Influenza, Human / Q000401:mortality*; D008962:Models, Theoretical; D011014:Pneumonia / Q000401:mortality*; D014481:United States