3. 'Risk of bias' sensitivity analysis.
| Comparison | Effect measure | All data sets | Excluding studies at high risk of bias | VE absolute change | Change effect measure direction | Change in statistical significance | |||||||||
| Number of data sets | Effect estimate | LL 95% CI | UL 95% CI | Statistical significance | Number of data sets | Effect estimate* | LL 95% CI | UL 95% CI | Statistical significance | ||||||
| Analysis 1.1 | Influenza | Risk ratio | 8 | 0.22 | 0.11 | 0.41 | Significant | 5 | 0.25 | 0.12 | 0.26 | Significant | ‐4% | Unchanged | Unchanged |
| Analysis 1.2 | Influenza‐like illness | Risk ratio | 8 | 0.69 | 0.60 | 0.80 | Significant | 1 | 0.48 | 0.44 | 0.52 | Significant | 15% | Unchanged | Unchanged |
| Analysis 2.1 | Influenza | Risk ratio | 5 | 0.36 | 0.28 | 0.48 | Significant | 3 | 0.40 | 0.23 | 0.68 | Significant | ‐5% | Unchanged | Unchanged |
| Analysis 2.2 | Influenza‐like illness | Risk ratio | 7 | 0.64 | 0.54 | 0.76 | Significant | 0 | NA | NA | NA | NA | NA | NA | NA |
| Analysis 4.3 | Otitis media | Risk ratio | 1 | 0.48 | 0.22 | 1.03 | Not significant | 0 | 0 | 0 | 0 | ‐ | ‐ | Unchanged | Changed |
| Analysis 5.1 | Influenza | Risk ratio | 7 | 0.19 | 0.11 | 0.32 | Significant | 5 | 0.21 | 0.09 | 0.48 | Significant | ‐2% | Unchanged | Unchanged |
| Analysis 5.2 | Influenza‐like illness | Risk ratio | 8 | 0.69 | 0.6 | 0.80 | Significant | 3 | 0.53 | 0.39 | 0.74 | Significant | 16% | Unchanged | Unchanged |
| Analysis 5.3 | Otitis media (all episodes) | Risk ratio | 2 | 0.98 | 0.95 | 1.01 | Not significant | 1 | 0.98 | 0.95 | 1.01 | Not significant | 0% | Unchanged | Unchanged |
| Analysis 5.4 | Working days lost (number of events, parents) | Risk ratio | 2 | 0.69 | 0.46 | 1.03 | Not significant | 2 | 0.69 | 0.46 | 1.03 | Not significant | 0% | Unchanged | Unchanged |
| Analysis 5.5 | Drug prescriptions (number of events) | Risk ratio | 1 | 0.99 | 0.87 | 1.12 | Not significant | 1 | 0.99 | 0.87 | 1.12 | Not significant | 0% | Unchanged | Unchanged |
| Analysis 5.6 | Outpatients attendance for pneumonia and influenza | Risk ratio | 2 | 0.76 | 0.59 | 0.98 | Significant | 2 | 0.76 | 0.59 | 0.98 | Significant | 0% | Unchanged | Unchanged |
| Analysis 6.1 | Influenza | Risk ratio | 5 | 0.36 | 0.28 | 0.48 | Significant | 5 | 0.36 | 0.28 | 0.48 | Significant | 0% | Unchanged | Unchanged |
| Analysis 6.2 | Influenza‐like illness | Risk ratio | 4 | 0.72 | 0.65 | 0.79 | Significant | 2 | 0.35 | 0.15 | 0.81 | Significant | 37% | Unchanged | Unchanged |
| Analysis 7.1 | Influenza vs ILI (crude data) | Odds ratio | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | Unchanged | Unchanged |
| Analysis 7.2.1 | Children aged below 23 months ‐ fully vaccinated | Odds ratio | 7 | 0.60 | 0.39 | 0.94 | Significant | 4 | 0.46 | 0.29 | 0.73 | Significant | 14% | Unchanged | Unchanged |
| Analysis 7.2.2 | Children aged 24 to 59 months ‐ fully vaccinated | Odds ratio | 4 | 0.40 | 0.22 | 0.70 | Significant | 4 | 0.4 | 0.22 | 0.70 | Significant | 0% | Unchanged | Unchanged |
| Analysis 7.2.3 | Children aged 6 to 59 months ‐ fully vaccinated | Odds ratio | 5 | 0.45 | 0.32 | 0.62 | Significant | 5 | 0.45 | 0.32 | 0.62 | Significant | 0% | Unchanged | Unchanged |
| Analysis 7.2.4 | Children aged below 14 years old ‐ fully vaccinated | Odds ratio | 1 | 0.23 | 0.06 | 0.84 | Significant | 1 | 0.23 | 0.06 | 0.84 | Significant | 0% | Unchanged | Unchanged |
| Analysis 7.3 | Influenza‐like illness vs no symptoms | Odds ratio | 2 | 0.49 | 0.28 | 0.86 | Significant | 0 | 0 | 0 | 0 | ‐ | ‐ | Unchanged | Changed |
| Analysis 8.1 | Influenza | Risk ratio | 11 | 0.27 | 0.18 | 0.42 | Significant | 11 | 0.27 | 0.18 | 0.42 | Significant | 0% | Unchanged | Unchanged |
| Analysis 8.2 | Influenza‐like illness | Risk ratio | 12 | 0.69 | 0.62 | 0.77 | Significant | 5 | 0.50 | 0.38 | 0.67 | Significant | 19% | Unchanged | Unchanged |
| Analysis 8.3 | Secondary cases | Risk ratio | 1 | 1.68 | 0.56 | 4.99 | Not significant | 1 | 1.68 | 0.56 | 4.99 | Not significant | 0% | Unchanged | Unchanged |
| Analysis 8.4 | School absenteeism | Risk ratio | 2 | 0.49 | 0.26 | 0.92 | Significant | 2 | 0.49 | 0.26 | 0.92 | Significant | 0% | Unchanged | Unchanged |
| Analysis 8.5 | Lower respiratory tract disease | Risk ratio | 3 | 0.2 | 0.03 | 1.54 | Not significant | 2 | 0.52 | 0.08 | 3.37 | Not significant | ‐32% | Unchanged | Unchanged |
| Analysis 8.6 | Acute otitis media | Risk ratio | 7 | 1.00 | 0.79 | 1.26 | Not significant | 5 | 1.03 | 0.91 | 1.17 | Not significant | ‐3% | Changed | Unchanged |
| Analysis 8.7 | Hospitalisation due to acute otitis media | Risk ratio | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | Unchanged | Unchanged |
| Analysis 8.7.1 | Inactivated vaccine (2 doses) | Risk ratio | 2 | 1.41 | 0.62 | 3.24 | Not significant | 2 | 1.41 | 0.62 | 3.24 | Not significant | 0% | Unchanged | Unchanged |
| Analysis 8.8 | Consequences of acute otitis media | Mean difference | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | ‐ | Unchanged | Unchanged |
| Analysis 8.8.1 | Inactivated vaccine, 2 doses (the arm of the trial) visits (the outcome measure) | Mean difference | 2 | ‐0.02 | ‐0.27 | 0.23 | Not significant | 2 | ‐0.02 | ‐0.27 | 0.23 | Not significant | ‐ | Unchanged | Unchanged |
| Analysis 8.8.2 | Inactivated vaccine (2 doses; courses of antibiotics | Mean difference | 2 | 0.13 | ‐0.36 | 0.63 | Not significant | 2 | 0.13 | ‐0.36 | 0.63 | Not significant | ‐ | Unchanged | Unchanged |
| Analysis 8.9 | Outpatients attendance for pneumonia and influenza | Risk ratio | 2 | 0.76 | 0.59 | 0.98 | Significant | 1 | 0.85 | 0.75 | 0.96 | Significant | ‐9% | Unchanged | Unchanged |
| Analysis 8.10 | Working days lost (number of events, parents of children 6 to 36 months of age) | Risk ratio | 2 | 0.69 | 0.46 | 1.03 | Not significant | 1 | 0.83 | 0.71 | 0.98 | Significant | ‐14% | Unchanged | Changed |
| Analysis 8.11 | Drug prescriptions (number of events, 6 to 36 months of age) | Risk ratio | 1 | 0.99 | 0.87 | 1.12 | Not significant | 1 | 0.99 | 0.87 | 1.12 | Not significant | 0% | Unchanged | Unchanged |
CI: confidence interval ILI: influenza‐like illness LL: lower limit NA: not applicable RR: risk ratio UL: upper limit VE: vaccine efficacy/effectiveness VE absolute change = (1 ‐ RR*) ‐ (1 ‐ RR) *: effect estimate excluding data sets at high risk of bias