Table 2.
Risk estimate of Guillain–Barré syndrome expressed by the pooled effect size in specific subgroups (sensitivity analyses).
| Critical Variable | High-Quality Studies | All Studies | |||
|---|---|---|---|---|---|
| Study Records | ES1 (95% CI2) | Study Records | ES (95% CI) | ||
| Time window | shorter3 | 17 | 1.19 (0.99–1.44) | 18 | 1.20 (1.00–1.44) |
| longer4 | 7 | 1.08 (0.77–1.52) | 12 | 1.12 (0.89–1.42) | |
| Age (years) | ≥65 | 5 | 1.11 (0.88–1.39) | 5 | 1.11 (0.88–1.39) |
| Study (type) | C-C | 4 | 0.97 (0.62–1.53) | 6 | 1.05 (0.74–1.48) |
| C | 4 | 1.56 (1.16–2.09) | 7 | 1.39 (1.10–1.75) | |
| SCCS | 5 | 1.25 (0.94–1.65) | 5 | 1.25 (0.94–1.65) | |
| SCRI | 7 | 0.98 (0.72–1.34) | 7 | 0.98 (0.72–1.34) | |
| Geographic region | North America | 13 | 1.24 (1.02–1.50) | 16 | 1.22 (1.02–1.45) |
| Europe | 5 | 0.90 (0.58–1.40) | 5 | 0.90 (0.58–1.40) | |
| Influenza season | 2009–2010 | 4 | 1.43 (1.03–1.97) | 4 | 1.43 (1.03–1.97) |
| 2010–2011 | 3 | 1.35 (0.88–2.07) | 3 | 1.35 (0.88–2.07) | |
1 ES, effect size determined using the random-effect model; 2 CI, confidence interval; 3 shorter time window (from 1st day to 42th day); 4 longer time window (from 1st day to 43rd–365th day).