The World Health Organization (WHO) has described pH1N1 as a moderate” pandemic. Many flu experts have never been comfortable with qualitative terms such as “mild” or “moderate”, perhaps in part because they also minimize the import of the disease, and can dissuade publics from taking protective action.
Researchers from the National Institites of Health (NIH) have devised what they term is an “apples-to-apples” methodology to estimate the burden of disease on a population. The metric, termed “Years of Life Lost” (YLL), takes into account the age-distribution of disease-related deaths and extrapolates potential years of life lost across age groups. Expressed as a function, the higher the numbers of deaths, and the lower the mean-age of deaths, the higher is YLL.
NIH researchers describe the impact of pH1N1 as “significant.” By their YLL metric, the burden of p1N1 exceeds that of typical seasonal flu dominated by Influenza A H3N2 virus. NIH research suggests pH1N1 may have had a comparable burden to the (Hong Kong) flu of 1968 (also described as a relatively mild pandemic).
much more via Op-Ed: Measuring the Impact of Pandemic H1N1 in “Years of Life Lost” still shows a Moderate Flu Burden – influenza monitor.