Table 2.
Pandemic influenza vaccine effectiveness in the surveillance-based and cycEVA studiesa, season 2009-2010, Spain
| Surveillance-based study | cycEVA study | ||||
|---|---|---|---|---|---|
| Included population | N | PIVE % (95%CIb) | N | PIVE % (95%CIb) | |
| Crude | All patients | 1326 | 35 (-38; 73) | 436 | 58 (-81; 95) |
| ▪ Delay onset-swabbing less than four days | 1175 | 35 (-45; 74) | 381 | 57(-87; 95) | |
| EU case definition | 701 | 14 (-131; 72) | 377 | 53 (-109; 95) | |
| ▪ Delay onset-swabbing less than four days | 627 | 5 (-161; 70) | 336 | 64 (-104; 95) | |
| Adjusted models | All patients | ||||
| ▪ full modelc | 301 | 75 (-293; 98) | |||
| ▪ SISSS covariatesd | 993 | 62 (-5; 87) | 351 | 65 (-221; 96) | |
| All patients and delay onset-swabbing less than four days | |||||
| ▪ full modelc | 258 | 77 (-296; 98) | |||
| ▪ SISSS covariatesd | 853 | 58 (-21; 85) | 302 | 67 (-211; 97) | |
| EU case definition | |||||
| ▪ full modelc | 255 | 71 (-402; 98) | |||
| ▪ SISSS covariatesd | 644 | 41 (-95; 82) | 299 | 59 (-300; 96) | |
| EU case definition and delay onset-swabbing less than four days | |||||
| ▪ full modelc | 231 | 72 (-290; 99) | |||
| ▪ SISSS covariatesd | 568 | 48 (-110; 82) | 263 | 68 (-215; 97) | |
a Cases and controls recruited between week 48/2009 and week 8/2010 and with a delay symptom onset-swabbing less than eight days; b CI = confidence interval; c Adjusted for age group, sex, seasonal vaccination, chronic conditions, previous hospitalizations, number of GP visits in the previous year, functional status, smoking, previous influenza vaccination, risk factors for pandemic influenza, and month of swabbing; d Adjusted for age group, sex, seasonal vaccination, chronic conditions, pregnancy, and month of swabbing; SISSS = Spanish Influenza Sentinel Surveillance.