Latent Tuberculosis Infection Testing Strategies for HIV-Positive Individuals in Hong Kong

Key Points Question In a setting with low HIV-tuberculosis incidence, is repeated testing for latent tuberculosis infection (LTBI) cost-effective for managing individuals with HIV who have negative LTBI test results at baseline? Findings In this decision analytical model using a cost-effectiveness analysis, based on 3130 HIV-positive individuals in Hong Kong, China, a strategy of baseline LTBI testing followed by up to 3 subsequent annual tests could avert a similar proportion of new tuberculosis infections while incurring a lower cost compared with annually repeated testing. The strategy did not meet the willingness-to-pay threshold but would likely be cost-effective if the threshold were raised. Meaning The findings suggest that less intense subsequent LTBI testing strategies may be effective and are likely cost-effective.


Tested baseline LTBI positive, without LTBI treatment
where

Tested baseline LTBI positive, received LTBI treatment
where TBdxb_tx[i] refers to TB reactivation rate for patients tested LTBI positive received LTBI treatment;

Tested LTBI positive at followups, without LTBI treatment
where TBdxf[i] refers to TB reactivation rate for patients tested LTBI positive but not yet received LTBI treatment, and at baseline, it was the same as TBdxntest[i];

Tested LTBI positive at followups, received LTBI treatment
where

eFigure 9. Incremental Cost-Effectiveness Ratio (ICER Plane) of LTBI Screening Strategies Under Different Coverage of Antiretroviral Therapy, LTBI Testing and Treatment, and TB treatment, 2017-2023
Screening strategies include strategy A: baseline screening ONLY; strategy B: baseline screening AND annual testing for risk groups; strategy C: baseline screening AND biennial testing for all until tested LTBI positive; strategy D: baseline screening AND at most three subsequent LTBI tests; and strategy E: baseline screening AND annual testing for all until tested LTBI positive. These strategies are under different coverage of antiretroviral therapy (ART), LTBI testing and treatment and TB treatment, including Scenario 1: baseline value for all; scenario 2: 100% coverage for all; scenario 3: baseline value for LTBI testing, and 100% for the rest; scenario 4: baseline value for LTBI testing and ART, and 100% for LTBI treatment and TB treatment; and scenario 5: baseline value for ART, and 100% for the rest. The incremental cost and quality-adjusted life-years (QALY) gained were compared with status quo (scenario E1).