Table 3. Results of Primary and Secondary Outcome Analyses in a Study of the Association of a Meningococcus Group B Vaccine With Group B Invasive Meningococcal Disease Among Children in Portugal.
| Analysis | No. of participants/total No. (%) | Absolute difference (95% CI), % | Odds ratio (95% CI) | ||
|---|---|---|---|---|---|
| Cases | Controls | Crudea | Matched | ||
| Primary | |||||
| Cases with group B disease and controls aged ≥134 d fully immunized for ageb | 5/69 (7.2) | 33/142 (23.2) | −16.0 (−26.3 to −5.7) | 0.26 (0.10 to 0.69) | 0.21 (0.08 to 0.55)c |
| Secondary | |||||
| Cases with any invasive meningococcal disease and controls aged ≥134 d and fully immunized for ageb | 6/85 (7.1) | 39/175 (22.3) | −15.2 (−24.3 to −6.1) | 0.26 (0.11 to 0.65) | 0.22 (0.09 to 0.53)c |
| Cases with group B disease and controls aged ≥74 d who received ≥1 vaccine dose | 8/82 (9.8) | 50/168 (29.8) | −20.0 (−30.3 to −9.7) | 0.26 (0.11 to 0.57) | 0.18 (0.08 to 0.44)c |
| Cases with any invasive meningococcal disease and controls aged ≥74 d who received ≥1 vaccine dose | 11/98 (11.2) | 61/201 (30.3) | −19.1 (−28.8 to −9.5) | 0.29 (0.14 to 0.58) | 0.23 (0.11 to 0.49)c |
| Sensitivity (including purchasing power)d | |||||
| Cases with group B disease and controls aged ≥134 d fully immunized for ageb | 5/69 (7.2) | 33/142 (23.2) | −16.0 (−26.3 to −5.7) | 0.26 (0.10 to 0.69) | 0.21 (0.07 to 0.65) |
a
Unmatched analysis of entire case cohort against the control cohort.
b
Fully immunized is considered 2 or more doses 14 or more days prior to presentation for those aged 2 to 15 months and either 2 or more doses in infancy plus 1 dose after the first birthday or 2 or more doses after the first birthday with completion at least 14 days prior to presentation for those aged 16 months and older.
c
Matched conditional logistic regression analysis with no additional covariates.
d
Adjusted for purchasing power linked to the first half of the postcode (municipality) of residence.