Table 2 Odds ratios$ of ILI, any virus, influenza (A or B), influenza A, influenza B on length of 445 school instruction, grade, sex, and 446 self-reported vaccination status among schoolchildren in Pittsburgh, PA. Variables significant at the 95% level are shown in bold
Response variable* | |||||
|---|---|---|---|---|---|
Symptomatic infection | Laboratory confirmed infection | ||||
ILI | Any respiratory virus% | Influenza (A or B) | Influenza A | Influenza B | |
Random effect variables | Percent of variance attributable to random effect^ | ||||
School | 12.8 | 11.2 | 20.1 | 17.0 | 26.5 |
District | 0.0 | 1.5 | 1.9 | 0.0 | 9.6 |
Residuals | 87.2 | 87.3 | 78.0 | 83.0 | 63.9 |
Fixed effect variables | Odds ratio (95% Confidence Intervals) | ||||
Intercept | 0.43 (0.29–0.65) | 0.28 (0.16–0.49) | 0.19 (0.09–0.40) | 0.06 (0.03–0.14) | 0.10 (0.04–0.25) |
Duration of attendance | |||||
Full day (n = 1880) | 1 | 1 | 1 | 1 | 1 |
Half day (n = 197) | 0.35 (0.21–0.57) | 0.28 (0.15–0.51) | 0.20 (0.10–0.43) | 0.38 (0.12–1.17) | 0.19 (0.08–0.45) |
Grade (linear term) | 0.93 (0.87–1.00) | 0.91 (0.84–0.99) | 0.85 (0.77–0.95) | 0.85 (0.72–0.99) | 0.88 (0.78–1.00) |
Sex | |||||
Male (n = 1082) | 1 | 1 | 1 | 1 | 1 |
Female (n = 995) | 0.91 (0.73–1.13) | 0.81 (0.62–1.05) | 0.94 (0.69–1.29) | 1.00 (0.59–1.70) | 0.90 (0.63–1.29) |
Vaccination | |||||
No (n = 850) | 1 | 1 | 1 | 1 | 1 |
Yes (n = 694) | 0.70 (0.54–0.90) | 0.80 (0.59–1.08) | 0.81 (0.57–1.17) | 0.59 (0.32–1.12) | 0.90 (0.60–1.36) |
Not reported (n = 533) | 0.76 (0.58–1.01) | 0.74 (0.53–1.03) | 0.80 (0.54–1.20) | 0.63 (0.32–1.25) | 0.86 (0.54–1.37) |