Table 4.
Self-controlled risk interval and historical comparison analysis of pre-specified claims-identified outcomes following trivalent influenza virus vaccine in the 2010–2011 influenza season.
| Outcome | Age | Cases in the risk window (N) | Cases in the comparison window (N) | Incidence rate ratio | 95% confidence limits | Doses administered | Doses administered in historical cohort | |
|---|---|---|---|---|---|---|---|---|
| Self-controlled risk interval analysis | ||||||||
| Seizure | 6–59 months | 5 | 20 | 0.88 | 0.26 | 2.40 | 185,144 | NA |
| Bell’s Palsy | All Ages | 80 | 91 | 0.88 | 0.65 | 1.19 | 1,158,932 | NA |
| ≤24 years | 7 | 9 | 0.78 | 0.29 | 2.09 | 436,905 | NA | |
| ≥25 years | 73 | 82 | 0.89 | 0.65 | 1.22 | 722,027 | NA | |
| Other cranial nerve disorders | All Ages | 226 | 395 | 1.14 | 0.97 | 1.35 | 1,158,932 | NA |
| ≤24 years | 15 | 28 | 1.07 | 0.57 | 2.01 | 436,905 | NA | |
| ≥25 years | 221 | 367 | 1.15 | 0.97 | 1.36 | 722,027 | NA | |
| Central demyelinating disease | All Ages | 184 | 355 | 1.04 | 0.87 | 1.24 | 1,158,932 | NA |
| ≤24 years | 5 | 26 | 0.38 | 0.15 | 1.00 | 436,905 | NA | |
| ≥25 years | 179 | 329 | 1.09 | 0.91 | 1.31 | 722,027 | NA | |
| Guillian-Barré Syndrome | All Ages | 14 | 14 | 1.00 | 0.45 | 2.23 | 1,158,932 | NA |
| ≤24 years | 2 | 0 | – | – | – | 436,905 | NA | |
| ≥25 years | 12 | 14 | 0.86 | 0.40 | 1.85 | 722,027 | NA | |
| Disorders of the peripheral nervous system and neuropathy | All Ages | 2239 | 4325 | 1.04 | 0.98 | 1.09 | 1,158,932 | NA |
| ≤24 years | 64 | 100 | 1.28 | 0.94 | 1.75 | 436,905 | NA | |
| ≥25 years | 2175 | 4225 | 1.03 | 0.98 | 1.08 | 722,027 | NA | |
| Historical comparison analysis | ||||||||
| Anaphylaxis | All Ages | 2 | 1 | 6.70 | 0.60 | 74.74 | 1,158,932 | 3,508,144 |
| ≤24 | 1 | 0 | – | – | – | 436,905 | 1,559,970 | |
| ≥25 | 1 | 1 | – | – | – | 722,027 | 1,948,174 | |
| Ataxia | All Ages | 11 | 43 | 0.69 | 0.35 | 1.34 | 1,158,932 | 3,508,144 |
| ≤24 | 3 | 7 | 1.49 | 0.39 | 5.78 | 436,905 | 1,559,970 | |
| ≥25 | 3 | 36 | 0.56 | 0.26 | 1.21 | 722,027 | 1,948,174 | |
| Encephalitis/myelitis/encephalomyelitis | All Ages | 5 | 36 | 0.39 | 0.15 | 1.01 | 1,158,932 | 3,508,144 |
| ≤24 | 2 | 10 | 0.69 | 0.15 | 3.16 | 436,905 | 1,559,970 | |
| ≥25 | 3 | 26 | 0.30 | 0.09 | 1.00 | 722,027 | 1,948,174 | |
| Guillain-Barre Syndrome | All Ages | 14 | 33 | 1.17 | 0.62 | 2.19 | 1,158,932 | 3,508,144 |
| ≤24 | 2 | 4 | 1.78 | 0.32 | 9.73 | 436,905 | 1,559,970 | |
| ≥25 | 12 | 29 | 1.10 | 0.56 | 2.17 | 722,027 | 1,948,174 | |
| Angioneurotic edema, allergic reaction and urticaria | All Ages | 141 | 510 | 0.86 | 0.71 | 1.03 | 1,158,932 | 3,508,144 |
| ≤24 | 82 | 304 | 0.95 | 0.75 | 1.21 | 436,905 | 1,559,970 | |
| ≥25 | 59 | 206 | 0.75 | 0.56 | 1.00 | 722,027 | 1,948,174 | |
| Hemorrhagic stroke | All Ages | 72 | 193 | 1.01 | 0.77 | 1.33 | 1,158,932 | 3,508,144 |
| ≤24 | 3 | 15 | 0.70 | 0.20 | 2.42 | 436,905 | 1,559,970 | |
| ≥25 | 69 | 178 | 1.04 | 0.78 | 1.37 | 722,027 | 1,948,174 | |
| Ischemic stroke | All Ages | 180 | 589 | 0.82 | 0.69 | 0.97 | 1,158,932 | 3,508,144 |
| ≤24 | 6 | 14 | 1.58 | 0.61 | 4.11 | 436,905 | 1,559,970 | |
| ≥25 | 174 | 575 | 0.80 | 0.68 | 0.95 | 722,027 | 1,948,174 | |
| Narcolepsy and cataplexy | All Ages | 67 | 234 | 0.80 | 0.62 | 1.06 | 1,158,932 | 3,508,144 |
| ≤24 | 1 | 19 | 0.19 | 0.03 | 1.42 | 436,905 | 1,559,970 | |
| ≥25 | 66 | 215 | 0.85 | 0.65 | 1.13 | 722,027 | 1,948,174 | |