Table 2.
Main outcomes of randomized trials of pneumococcal vaccines
| Outcome | Patient group | Number of trials | Number of patients | Percent affected without vaccine | Percent affected with vaccine | Relative risk (95%CI) | Number-needed-to-treat (95%CI) |
| All pneumonias | Healthy immunocompetent | 3 | 14 567 | 6.5 | 3.1 | 0.56 (0.47 to 0.66) | 29 (24 to 36) |
| Elderly or high risk | 5 | 7 837 | 6.8 | 7 | 1.08 (0.92 to 1.27) | ||
| Pneumococcal pneumonias | Healthy immunocompetent | 3 | 14 567 | 3.1 | 0.5 | 0.16 (0.11 to 0.23) | 38 (33 to 45) |
| Elderly or high risk | 7 | 22 479 | 1.9 | 1.7 | 0.88 (0.72 to 1.07) | ||
| Lower respiratory tract infection | Healthy immunocompetent | 2 | 10 067 | 5.6 | 4.1 | 0.85 (0.71 to 1.02) | |
| Elderly or high risk | 3 | 17 195 | 9.4 | 9.9 | 1.06 (0.97 to 1.16) | ||
| Pneumonia-related death | Healthy immunocompetent | 1 | 11 958 | 1.6 | 1.1 | 0.70 (0.50 to 0.96) | 213 (114 to 1660) |
| Elderly or high risk | 8 | 22 559 | 1.1 | 1 | 0.93 (0.72 to 1.20) | ||
| Pneumococcal bacteraemia | Healthy immunocompetent | 1 | 5 427 | 3.8 | 0.7 | 0.18 (0.09 to 0.34) | 32 (26 to 44) |
| Elderly or high risk | 3 | 927 | 1.4 | 0.8 | 0.53 (0.14 to 1.94) | ||
Note: Details of patient groups are given in the textNumbers-needed-to-treat are only given where there is a statistical benefit of treatment over control.