Observed versus expected* analysis for Bell's palsy cases reported in Europe
| Sensitivity analysis | Time to onset | N observed [95%CI] | N expected* (Rowlands et al.15) |
|---|---|---|---|
| 100/100 | 7 | 10 [4.79; 18.39] | 34 |
| 100/100 | 30 | 13 [6.91; 22.23] | 147 |
| 75/75 | 7 | 12 [6.19; 20.96] | 26 |
| 75/75 | 30 | 16 [9.14; 25.99] | 110 |
The expected number of cases was calculated for the age distribution from cases in the safety database for the reference study by Rowland et al.15 In the sensitivity analysis, it is assumed that there is 25% of under-reporting and that 75% of the doses distributed have been administered.
Vaccination coverage information among women vaccinated in each age strata in Rowlands et al.15 is not available. Therefore, the proportion of all Cervarix® spontaneous cases reported in Europe within each age stratum was used to weight each age stratum provided in the reference. Adjusted background incidence rates (representative of the vaccinated population) were calculated by taking the weighted average of the reference incidence rate. This adjusted background incidence rate is used to make the comparison with the observed incidence rate.