This type of medication can only be obtained when specifically prescribed by a medical doctor. It is therefore unwanted that many persons have such medication at home, allowing them to take it whenever they see fit. Yet 2% of the respondents, who did not consult a physician, took antibiotics for their ILI episode. This is about four times the rate that was reported in a previous general population sample in Belgium. Antibiotic use for ILI was found to be much higher in primary care. For comparison, Butler et al reported almost 30% antibiotics use in adults with a new or worsening cough or clinical presentation suggestive of lower respiratory tract infection in Antwerp. The benefit of antibiotics for an ILI like bronchitis is Avridine little. Also, despite the modest benefit of antivirals, in this study they are used more than twice as often to treat ��likely flu�� patients compared to ��unlikely flu�� ILI patients in ambulatory care. To our knowledge, this is the only study having used SF-6D as a measure for the QoL associated with ILI and clinically diagnosed flu retrospectively. We found a lower impact of flu on QoL than previous published studies. Possibly, our study underestimated the impact of flu on the QoL because we used as definition for flu the clinical diagnosis of a medical doctor and not a laboratory test like van Hoek et al and Hollmann et al. Our study would underestimate the impact if ILI patients falsely diagnosed as having flu, PF-04479745 generally experienced less of a burden than true flu patients. Ours is the only study to date, which modelled the loss in QALY��s as a function of important covariates. As expected, having an underlying illness leads to more QALY��s lost. Also, the older the patient, the more QALY��s they lost. This is in line with Sander et al, who found that older patients lost more QALY��s than younger patients. This age-related trend in our study is due to elderly people being sick for a longer time, because we did not find the QoL score to depend on age. Note however that we probably overestimated the QALY��s lost for elderly as compared to younger patients, because of the way we calculated the QALY��s lost. Namely, we assumed persons without flu to be in perfect health, irrespective of their age. This choice was made because currently no baseline QoL data exist for the Belgian population.