TABLE 1.
Variable | All invited (N = 1324)b |
All participants (N = 357) |
Serologically tested cases (n = 72) |
|||||||
Total with blood test | Positive H1N1 (n = 34) |
Negative H1N1 (n = 38) |
P-value | |||||||
N | % | n | % | n | n | % | n | % | ||
Age | NS | |||||||||
0–17 years | 359 | 29 | 106 | 30 | 0* | – | – | – | – | |
18–40 years | 577 | 44 | 127 | 36 | 32 | 18 | 56 | 14 | 44 | |
>40 years | 275 | 27 | 122 | 34 | 40 | 16 | 40 | 24 | 60 | |
Missing | 2 | 0 | ||||||||
Gender | NS | |||||||||
Male | 577 | 46 | 146 | 41 | 24 | 12 | 50 | 12 | 50 | |
Female | 665 | 54 | 210 | 59 | 48 | 22 | 46 | 26 | 54 | |
Missing | 1 | 0 | 0 | |||||||
Smoking status | NS | |||||||||
Smoker | 71 | 20 | 19 | 7 | 37 | 12 | 63 | |||
Non-smoker | 286 | 80 | 53 | 27 | 51 | 26 | 49 | |||
Level of education | NS | |||||||||
Primary and secondary school | 57 | 16 | 7 | 2 | 29 | 5 | 71 | |||
High school | 84 | 23 | 22 | 11 | 50 | 11 | 50 | |||
Higher education <4 years | 61 | 17 | 18 | 7 | 39 | 11 | 61 | |||
Higher education >4 years | 78 | 22 | 25 | 14 | 56 | 11 | 44 | |||
Missing | 77 | 22 | 0 |
Confirmed H1N1 was defined as a serum HAI titre of ≥40 and negative H1N1 (<10) as HAI titres = 5. NS, not statistically significant. Number (n) and proportion of responders. *, not applicable. Only cases ≥18 years old were asked to provide blood samples.
Percentage is calculated vertically (within the characteristic) for all invited and all participants, while it is calculated horizontally (within each level of the characteristic) for the serologically tested subsample.
Eighty-two patients missing due to lack of data on gender and age.