Crude and adjusted (by age and tuberculin skin test results) estimates of the number of latent infection treatments necessary to prevent one case of tuberculosis.

Abbreviations: CI, confidence interval; TST, tuberculin skin test; LTBI, latent tuberculosis infection.
aProportion of all reported contacts who did not receive LTBI treatment.
bProportion of contacts with tuberculosis who started treatment versus those who did not start treatment for latent tuberculosis infection.
cWhen the number of necessary treatments equals 0 (zero), the effect of treatment is nonsignificant.