Table 6.
Crude and adjusted relative risk estimates (odds ratio and 95% confidence intervals) from pooled analyses for Guillain-Barré syndrome after pandemic influenza A (H1N1) 2009 vaccination given ≤6 weeks before onset of symptoms
| Unadjusted matched analysis* | ILI/URTI adjusted only | Adjusted for seasonal influenza vaccination only | Adjusted for seasonal influenza vaccination and ILI/URTI | |
|---|---|---|---|---|
| No exposure as reference | ||||
| Netherlands, UK, Sweden, Denmark | 2.8 (1.3 to 6.0) | — | — | — |
| Netherlands, UK, Sweden | 2.0 (0.9 to 4.8) | 1.4 (0.5 to 3.5) | 1.5 (0.6 to 3.9) | 1.0 (0.3 to 2.7) |
| Netherlands, UK | 1.9 (0.7 to 5.3) | 1.2 (0.4 to 3.7) | 1.2 (0.4 to 3.8) | 0.7 (0.2 to 2.5) |
| Restricted to people without ILI/URTI; no exposure as reference | ||||
| Netherlands, UK, Sweden | 1.9 (0.7 to 5.6) | — | 1.2 (0.4 to 4.0) | — |
| Netherlands, UK | 2.5 (0.6 to 10.7) | — | 1.2 (0.3 to 5.8) | — |
ILI/URTI=influenza-like illness or upper respiratory tract infection.
*Matched on age (within 1 year), sex, and index date; additionally matched on GP practice in Netherlands and UK.