META-ANALYSIS | STUDIES INCLUDED, N | PATIENTS INCLUDED, N | INCIDENCE RATE IN THOSE VACCINATED WITH PPSV23, % | INCIDENCE RATE IN UNVACCINATED SUBJECTS, % | METRIC USED TO ESTIMATE EFFECTIVENESS | ESTIMATE (95% CI) | SIGNIFICANT STATISTICAL HETEROGENEITY |
---|---|---|---|---|---|---|---|
IPD | |||||||
• Kraicer-Melamed et al, 2016, cohort studies49 | 8 | NA | NA | NA | Vaccine effectiveness* | 50% (21% to 69%) | Yes |
• Kraicer-Melamed et al, 2016, case-control studies49 | 4 | NA | NA | NA | Vaccine effectiveness* | 54% (32% to 69%) | Yes |
• Moberley et al, 201350 | 11 | 36 489 | 0.08 | 0.35 | Odds ratio | 0.26 (0.14 to 0.45) | No |
Pneumococcal CAP | |||||||
• Schiffner-Rohe et al, 201651 | 4 | 29 218 | 0.56 | 0.70 | Odds ratio | 0.72 (0.33 to 1.58) | Yes |
• Diao et al, 201652 | 3 | 2293 | 2.90 | 5.03 | Relative risk | 0.54 (0.18 to 1.65) | Yes |
• Moberley et al, 201350 | 10 | 35 483 | 0.08 | 0.35 | Odds ratio | 0.26 (0.15 to 0.46) | No |
All-cause CAP | |||||||
• Kraicer-Melamed et al, 2016, trials49,53 | 3 | NA | NA | NA | Vaccine efficacy* | −10% (−36% to 12%) | No |
• Kraicer-Melamed et al, 2016, cohort studies49 | 9 | NA | NA | NA | Vaccine effectiveness* | 17% (−26% to 45%) | Yes |
• Kraicer-Melamed et al, 2016, case-control studies49 | 7 | NA | NA | NA | Vaccine effectiveness* | 7% (−10% to 21%) | Yes |
• Diao et al, 201652 | 7 | 156 010 | 0.54 | 0.61 | Relative risk | 0.87 (0.76 to 0.98) | No |
• Moberley et al, 201350 | 16 | 47 734 | 4.32 | 6.17 | Odds ratio | 0.72 (0.56 to 0.93) | Yes |
CAP—community-acquired pneumonia, IPD—invasive pneumococcal disease, NA—not available, PPSV23—23-valent pneumococcal polysaccharide vaccine.
↵* Vaccine effectiveness or efficacy is defined as a reduction in relative risk in the vaccinated population compared with the unvaccinated population.54