Numbers of individuals with positive immunodiagnostic results needed to treat (NNT) to prevent a case of tuberculosis
| Population | First author [ref.] | Subpopulations | NNT | Test |
| Contacts | Zellweger [2] | 37.0 | ELISA | |
| 36.5 | ELISPOT | |||
| Geis [4] | 34.5 | ELISA | ||
| Sloot [5] | All | 88.9 | ELISA and/or TST | |
| Close contacts (first circle) | 30.4 | |||
| Immunocompromised patients | Sester [3] | HIV, CRF, SOT, SCT, RA | 49.7 | TST |
| 79.5 | ELISA | |||
| 64.3 | ELISPOT | |||
| HIV | 14.0 | TST | ||
| 25.5 | ELISA | |||
| 21.3 | ELISPOT |
The low number of TB cases present in each of the studies precludes the calculation of meaningful confidence intervals around the NNT. TST: tuberculin skin test; CRF: chronic renal failure; SOT: solid organ transplantation; SCT: stem cell transplantation; RA: rheumatoid arthritis.