Choi K, Thacker S B
Am J Epidemiol. 1981 Mar;113(3):227-35. doi: 10.1093/oxfordjournals.aje.a113091.
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.
在本文中，将与肺炎和流感相关的死亡百分比（P&I比率）作为流感活动的指标以及量化流感对死亡率影响的一种方法进行评估。对1962年至1979年的数据进行分析表明，P&I比率是流感活动的准确指标，这一点已得到发病率独立系统和实验室监测的证实。评估了一条使用P&I比率来检测流感疫情爆发的规则。结果发现，该规则比基于回归模型的规则更具特异性，但在过去17年中并未更及时地检测到流感疫情爆发。在自回归积分移动平均（ARIMA）预测模型中使用P&I比率能对预期的肺炎和流感死亡率做出最准确的预测。
