Survival and Longevity
The Two Demographies of Influenza
In the past, infectious morbidity and mortality were usually reported on a weekly basis. It is now apparent that there will be enormous growth in the availability of daily electronic data as a result of computerised record-keeping and reporting. Some of these data will be direct counts from doctors, hospitals and laboratories, but there will also be indirect information such as pharmaceutical sales, telephone calls to official medical help-lines, and the web searches counted in "Google flu watch". Switching from weekly to daily reporting will offer health planners the opportunity to rapidly identify new epidemics and pandemics of infectious diseases, and to make more timely decisions about interventions. At the same time, the data will require new statistical tools to aid real-time decision-making.
Our understanding of influenza pandemics has been aided by ex post analyses of the 5 pandemics in the modern era. This project treats daily data from the 1889/90 and 1918 pandemics as problems to be analysed in real-time. There are three main objectives of the methodology. First, to provide an accurate, daily estimate and confidence interval for the Reproductive Number of a pandemic - the number of secondary cases produced by each primary case in a totally susceptible population. This number indicates the pace at which a pandemic is growing or declining. Second, to base the estimate on multiple sources that are likely to have different characteristics. For example, we would expect that hospital admissions would lag behind doctor-patient contacts. Finally, the model will allow for the fact that daily data may be subject to weekly reporting cycles that are not part of the underlying disease process - e.g. optional events such as doctor-visits are often displaced from weekends and holidays.
Research keywords: Ageing, Mortality and Longevity; Biodemography; Health Care, Public Health, Medicine, and Epidemiology; Historical Demography