Table 6. Study site-specific and two-stagea pooled seasonal vaccine effectiveness against hospitalised influenza B among elderly people, I- MOVE + study, Europe, influenza season 2015/16.
| Study site | Inclusion period | Variables used for adjustmentb | Vaccinated /cases |
Vaccinated /controls |
Adjusted IVE | 95% CI | I-square |
|---|---|---|---|---|---|---|---|
| Finland | 2016w8–2016w15 | Date | 2/3 | 22/35 | 23.3 | -1,785.9 to 96.9 | – |
| France | 2016w4–2016w14 | Date, age, functional impairment | 17/26 | 87/120 | 18.1 | -105.6 to 67.4 | – |
| Italy | 2016w1–2016w12 | Date | 2/10 | 121/249 | 75.5 | -23.7 to 95.1 | – |
| Navarre | 2015w53–2016w17 | Date | 17/27 | 165/230 | 59.4 | -2.5 to 83.9 | – |
| Spain | 2016w2–2016w16 | Date, lung disease, dependency | 11/20 | 159/220 | 44.3 | -48.9 to 79.1 | – |
| two-stage pooled (n = 944) | – | – | – | – | 47.0 | 11.9 to 68.2 | 0.0% |
CI: confidence interval; I MOVE+: Integrated Monitoring of Vaccines in Europe plus; IVE: influenza vaccine effectiveness; w: week (International Organisation for Standardisation (ISO) week).
a Croatia, Hungary, Italy, Lithuania, the Netherlands, Poland, Portugal and Romania were excluded from the two-stage analyses because there were no vaccinated controls and/or cases.
b Date of onset and age modelled as restricted cubic spline with four knots.