Table. 5—

Total cost per active tuberculosis (TB) case detected using different screening tests, in a hypothetical cohort of 1,000 immigrants, with 1% prevalence of active TB#

TSTChest radiographSputum TB cultureSputum TB PCR (one sample)SerologyIn vitro tests of CMI
One specimenThree specimens
Cost to screen 1000 persons $700022000500001500007500019000§45000§
Cases of active TB detected n878.297.35.56.5
False-positive tests n470f23819.819.819.899178
Costs of work-up after positive test+ $92254472855404555852302016935609
Total cost for screening $992546928555404155558802303916980609
Total cost per active case detected $12407989867571728410990712212401
  • TST: tuberculin skin test; CMI: cell-mediated immunity. #: all costs in Canadian dollars; : sputum TB culture includes cost of sputum induction, but does not include acid-fast bacilli smear; +: average costs were $193 for the evaluation of persons with positive screening test in a chest specialist clinic 32, and costs do not include overhead, administration or patient costs; §: serology and CMI include the cost of drawing blood samples ($10); ƒ: assume that the prevalence of positive TST would be 50%.