The burden of influenza: evaluation of the Disability Adjusted Life Years (DALYs) and hospital utilization in Italy

Background In 2009, we took part at the project ‘‘Burden of Communicable Diseases in the European Union and EEA/EFTA countries (BCoDE)’’. Italy was chosen as one of the test countries to perform the field study in order to apply the methodology developed for estimating the burden of selected communicable diseases (CD). The aim of this abstract is to present the preliminary results for influenza and its impact in terms of DALYs on the Italian population. Methods Our starting point for the methodology was the approach taken by the Global Burden of Disease (WHO) for previous global estimates. The burden of influenza was determined based on data for the years 2005–2007. Since influenza notification is not mandatory in Italy and the sentinel surveillance system does not provide disaggregated data by gender and specific age groups, the decision was made to use the hospital discharges database of the Italian Ministry of Health. In developing the outcome tree for influenza we considered four different complications (pneumonia, otitis media, acute respiratory distress syndrome, sepsis) and their long-term sequelae. We provided best estimates of the transition probabilities, durations and disability weights. Underreporting for hospital discharges was corrected by a multiplication factor. Results In the time period considered, the burden of influenza in DALYs per year is 24,241, while the DALY rate per 100.000 is 39.4. The stratification by age shows a higher DALYs per year in the extreme groups of the age pyramid (0, 1–4 years and 80–84, 85+) for both genders.