Table 2:
BCG vaccination at birth and the occurrence of pulmonary and extrapulmonary tuberculosis, stratified by infection status and age
| Number of cohorts | Participants | Events | Adjusted odds ratio (95% CI) | |
|---|---|---|---|---|
|
| ||||
| Pulmonary tuberculosis | ||||
| All participants | ||||
| All ages | 14 | 57279 | 1250 | 0·81 (0·70–0·94) |
| <5 years | 14 | 7233 | 154 | 0·73 (0·48–1·11) |
| 5–9 years | 13 | 8630 | 82 | 0·79 (0·38–1·62) |
| 10–14 years | 13 | 7025 | 125 | 0·84 (0·50–1·40) |
| 15–24 years | 11 | 9217 | 311 | 1·20 (0·87–1·76) |
| 25–34 years | 8 | 7494 | 179 | 1·31 (0·86–1·99) |
| ≥35 years | 8 | 17680 | 399 | 0·81 (0·63–1·05) |
| Positive TST or IGRA | ||||
| All ages | 13 | 12594 | 738 | 0·80 (0·65–0·99) |
| <5 years | 13 | 1611 | 118 | 0·79 (0·46–1·34) |
| 5–9 years | 12 | 2046 | 59 | 0·96 (0·46–2·02) |
| 10–14 years | 12 | 1873 | 85 | 0·85 (0·44–1·63) |
| 15–24 years | 10 | 2105 | 192 | 1·16 (0·74–1·83) |
| 25–34 years | 7 | 1592 | 111 | 1·45 (0·73–2·91) |
| ≥35 years | 7 | 3367 | 173 | 0·80 (0·49–1·30) |
| Negative TST, IGRA, or both | ||||
| All ages | 13 | 18278 | 167 | 0·98 (0·65–1·46) |
| <5 years | 13 | 4352 | 33 | 0·65 (0·28–1·50) |
| 5–9 years | 12 | 4978 | 23 | 4·94 (0·65–37·57) |
| 10–14 years | 12 | 3251 | 23 | 0·97 (0·38–2·50) |
| 15–24 years | 10 | 2296 | 39 | 1·28 (0·54–3·05) |
| 25–34 years | 7 | 1244 | 18 | 0·92 (0·27–3·18) |
| ≥35 years | 7 | 2157 | 31 | 0·84 (0·30–2·31) |
| Extrapulmonary tuberculosis | ||||
| All participants | ||||
| All ages | 14 | 56183 | 144 | 0·96 (0·65–1·41) |
| <5 years | 14 | 7104 | 23 | 0·46 (0·19–1·12) |
| 5–9 years | 13 | 8571 | 18 | 0·54 (0·17–1·69) |
| 10–14 years | 13 | 6920 | 20 | 2·45 (0·54–11·08) |
| 15–24 years | 11 | 8941 | 35 | 1·43 (0·60–3·42) |
| 25–34 years | 8 | 7341 | 24 | 0·79 (0·35–1·79) |
| ≥35 years | 8 | 17306 | 24 | 2·92 (0·98–8·00) |
| Positive TST or IGRA | ||||
| All ages | 13 | 11 926 | 70 | 0·91 (0·48–1·73) |
| <5 years | 13 | 1508 | 15 | 0·55 (0·18–1·73) |
| 5–9 years | 12 | 1997 | 10 | 0·43 (0·12–1·54) |
| 10–14 years | 12 | 1799 | 11 | 0·71 (0·13–3·94) |
| 15–24 years | 10 | 1932 | 19 | 1·35 (0·43–4·27) |
| 25–34 years | 7 | 1484 | 3 | ·· |
| ≥35 years | 7 | 3206 | 12 | 2·58 (0·18–36·37) |
| Negative TST, IGRA, or both | ||||
| All ages | 13 | 18 236 | 35 | 1·03 (0·46–2·34) |
| <5 years | 13 | 4325 | 7 | 0·34 (0·07–1·51) |
| 5–9 years | 12 | 4961 | 7 | 1·05 (0·11–9·83) |
| 10–14 years | 12 | 3326 | 8 | ·· |
| 15–24 years | 10 | 2266 | 7 | 0·91 (0·18–4·73) |
| 25–34 years | 7 | 1228 | 4 | 0·97 (0·08–11·23) |
| ≥35 years | 7 | 2130 | 2 | ·· |
Events were a composite of both prevalent tuberculosis (diagnosed at or within 90 days of baseline) and incident tuberculosis (diagnosed more than 90 days after baseline). If the odds ratio is not presented, there was not enough statistical power due to small sample sizes or too few events. Each stratified model used separate, mixed-effects, binary, multivariable logistic regression analyses with study-level random effects. We assumed a conditional Bernoulli distribution of the response given the random effects. Models were adjusted for the variable of interest, baseline age, sex, previous tuberculosis, and whether data were collected prospectively or retrospectively. Age was adjusted within each age stratum. The number of events for the vaccinated and unvaccinated groups in each stratification can be found in the appendix (appendix pp 24–25). Analysing raw numbers might not translate well into adjusted odds ratios due to the mixed-effects model. IGRA=IFNγ release assay. TST=tuberculin skin test.