Controlled trials of the effect of BCG on mortality from causes other than tuberculosis among children in the USA and the UK (reported in papers published between 1948 and 1961)
| Study | Age followed | Allocation | BCG | No BCG | Reduction in mortality (95% CI)* |
|---|---|---|---|---|---|
| USA45 | 0–13 years | Alternate | N=231: 3/1261 (2.4‰) | N=220: 3/1320 (2.3‰) | –4% (–682% to 86%)† |
| USA46 | 0–15 years | Random | N=306: 49/2013.5 (24.3‰) | N=303: 51/1839.2 (27.7‰) | 12% (–33% to 42%)† |
| USA47 | 0–20 years | Alternate | N=1551: 49/16406 (3.0‰) | N=1457: 56/15207 (3.7‰) | 19% (–21% to 46%) |
| UK48 | 14–21 years | Odd/even | N=6700: 7/6700 (1.0‰)‡ § | N=6500: 10/6500 (1.5‰)‡ | 32% (–98% to 78%)† |
| USA49 | 0–16 years | Alternate | N=566: 14/566 (24.7‰)‡ | N=528: 25/528 (47.3‰)‡ | 48% (–4% to 75%) |
| UK48 | 14–21 years | Odd/even | N=14100: 8/14100 (0.6‰)‡ | N=16/13200 (1.2‰)‡ | 53% (–12% to 83%)† |
| Total | 25% (6% to 41%)¶ | ||||
| Twins35 | 0–17 months | Twins | 1/5 (89)=0.20 (0.02–1.68)** | DTP: 22/3 (164)=7.3 (2–38)** | p<0.001 |
Number of children: died/person-years (deaths per 1000 person-years).
↵* 100 × (1−BCG mortality/control mortality).
↵† Excludes deaths from accidents.
↵‡ Number of children died/number of children (deaths per 1000 children).
↵§ Vole vaccine used rather than BCG.
↵¶ 100 × (1−Mantel–Haenszel combined mortality ratio), test of homogeneity p=0.65, Stata version 10.
↵** Twins (BCG v DTP): female deaths/male deaths (number of female–male twin pairs)=ratio (95% CI); not randomised, but unbiased.
BCG, Bacillus Calmette–Guerin; DTP, diphtheria, tetanus and pertussis.