Influenza places a substantial burden, economic and otherwise, on the affected individuals and society. The clinical manifestations of the disease, as well as the epidemiology are well understood, for both adults and children, and this includes quality of life research, outcomes research, pharmacoeconomics, productivity, absenteism, presenteism (been less productive upon returning to work) and the like.

When it comes to children, data is available on the overall occurrence of influenza (in children), nevertheless much less information is available on the differential impact of influenza on health care for previously healthy children and those at high risk of developing influenza-related complications.

One can make the hypothesis that there is a correlation between "at risk" children and negative outcomes from the effect of influenza, and hence measures to prevent and treat influenza-related complications are certainly warranted for children at-risk.

A study published in Pharmacoeconomics in 2003, compared the frequency of influenza-related complications in healthy and `at-risk' children, and quantified the associated use of medical resources and costs. The researchers looked at data obtained from a large US-based health insurance plan database. The main outcomes - results - are undisputable: a total of 23,188 health insurance claims with an influenza diagnosis were identified over the 3-year period 1995-1997 (this is equivalent to 3,247,834 patient-years). Influenza-related complications were observed in approximately a quarter of the total diagnosed cases, with younger children (0-4 years of age) at substantially greater risk. The original hypothesis was validated: `at-risk' children were more likely to develop influenza-related complications than otherwise healthy children. The greatest difference in incidence rate in the 0-4 year age group were children with asthma, and in the 5-14 year age group for asthma and acute sinusitis.

When the researchers looked at pharmacoeconomics, the average direct medical costs of influenza in children under 15 years with complications were more than 3.5 times higher than those without.

When we look at the results from this, as well as other studies, it is obvious that measures to prevent and treat influenza-related complications are certainly warranted for "at-risk" children, although the elevated incidence rates for several common complications even among healthy children should prompt consideration of these measures for all children.