The mean age of the respondents was 45 years (median 45, range 16–82) and 45% were female (Table ). The respondents were fairly representative of the general population with respect to age, proportion of people living alone, and place of residence. Men and people with high income and education were somewhat overrepresented.
Sociodemographic variables of lay people aged 16 – 82 (n = 1,168) responding to an internet survey about a serious influenza epidemic
The majority of respondents had received information about influenza from the mass media (TV: 89%, newspapers: 85%, periodicals: 4%); a few directly from health authorities via internet or "influenza-phones" (Institute of Public Health: 2%, Food Safety Authority: 3%, GPs: 4%, Directorate of Health: 1%). Seventy-nine per cent of the respondents had received information from the mass media only. Sixty-five per cent trusted the information they had received directly or indirectly from authorities, while 9% distrusted it. In logistic regression, the odds for reporting overt distrust in or doubts about the information were greater among younger people (age < 45 years vs 45+, OR 1.9, 95% CI 1.4 – 2.4), those with poor self-reported health (poorer than "very good" vs "very good", OR 1.5, 95% CI 1.2 – 2.0), those with poor education (<14 years vs 14+, OR 1.4, 95% CI 1.1 – 1.8), those with a high perceived mortality risk (10,000+ deaths vs <10,000, OR 1.7, 95% CI 1.2 – 2.3) and people living in one specific region (south-west, OR 1.6, 95% CI 1.2 – 2.2 relative to the central region).
About one quarter of the respondents were uncertain about the mortality risk (number of fatalities) from a serious influenza epidemic, whereas the majority indicated it to be less than 1% (Table ). For 48% of respondents the perceived risk was lower than predicted by the health authorities. Relative risk reduction (RRR) and the number needed to be treated (NNT) with Tamiflu® were calculated except for respondents who were uncertain about the input numbers or indicated a greater number of fatalities with Tamiflu® than without. Among respondents for whom we could calculate RRR and NNT, the vast majority of NNTs were above 1,000 and half of RRRs greater than 50% (Table ). In total, only 12 (1%) of the respondents had purchased Tamiflu®.
Lay people's anticipations of fatalities and effect of Tamiflu® during a serious influenza epidemica
According to their responses, 80% would be "careful about personal hygiene", 9% would use face masks when outdoors, 2% would stay off work, 11% would stay at home and avoid contact with others, 4% would move to an isolated area (country side cottage, farm, etc.) while 16% would not take any special precautions if a serious influenza pandemic should break out. In logistic regression analysis, the odds for reporting isolation (i.e. stay home, stay off work or move to an isolated place) as a precaution were greater among those with poor self-reported health (poorer than "very good" vs "very good", OR 1.8, 95% CI 1.3 – 2.6) and those with high perceived fatality risk (10,000+ deaths vs <10,000, OR 3.2, 95% CI 2.2 – 4.8 compared to < 10,000 deaths).