Compared with no screening, TST screening led to a gain of 0.00 to 0.13 quality-adjusted life-months at an incremental cost ranging from $50 to $140, depending on the risk group.
Compared with the TST, IGRA screening led to a gain of 0.00 to 0.008 quality-adjusted life-months at an incremental cost ranging from -$10 (a saving) to $20, depending on the risk group.
In patients at high risk of reactivation, the incremental cost per QALY gained was less than $50,000 with the TST over no screening, and with the IGRA over the TST.
In people born abroad, the IGRA dominated the TST, as the IGRA was more effective and cheaper. This was due to a lower loss to follow-up and better specificity. The incremental cost per QALY for the IGRA over no screening was less than $100,000, for all subgroups, up to the age of 45 years.
In vulnerable populations, the incremental cost per QALY gained with the TST over no screening was $95,000 for the homeless, $104,600 for injection drug users, and $147,600 for former prisoners. For the IGRA over the TST it was $194,300 for the homeless and over $200,000 for injection drug users and former prisoners.
In patients with chronic conditions, neither screening was cost-effective; the cost-utility ratio for the TST over no screening was $129,000 for patients taking immunosuppressive medications.
The sensitivity analysis showed that the cost-utility estimates were sensitive to variations in the rate of reactivation tuberculosis. Assuming that all patients returned for their TST results, the TST dominated the IGRA in adults with close contacts. Variations in the patient's age and the quality-of-life adjustments also altered the findings.