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

Wong, Ngai Sze; Chan, Kenny Chi Wai; Wong, Bonnie Chun Kwan; Leung, Chi Chiu; Chan, Wai Kit; Lin, Ada Wai Chi; Lui, Grace Chung Yan; Mitchell, Kate M.; Lee, Shui Shan

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. This decision analytical model analyzes the cost-effectiveness of latent tuberculosis infection testing for individuals in Hong Kong with HIV who had negative latent tuberculosis infection test results at baseline. Importance: With immune recovery following early initiation of antiretroviral therapy (ART), the risk of tuberculosis (TB) reactivation among individuals with HIV could be reduced. The current strategy of annual latent TB infection (LTBI) testing should be revisited to increase cost-effectiveness and reduce the intensity of testing for individuals. Objective: To analyze the cost-effectiveness of LTBI testing strategies for individuals in Hong Kong with HIV who had negative LTBI test results at baseline. Design, Setting, and Participants: This decision analytical model study using a cost-effectiveness analysis included 3130 individuals with HIV in Hong Kong, China, which has an intermediate TB burden and a low incidence of HIV-TB coinfection. A system dynamics model of individuals with HIV attending a major HIV specialist clinic in Hong Kong was developed and parameterized by longitudinal clinical and LTBI testing records of patients during a 15-year period. The study population was stratified by age group, CD4 lymphocyte level, ART status, and right of abode. Alternative strategies for LTBI testing after a baseline test were compared with annual testing under different coverages of ART, LTBI testing, and LTBI treatment scenarios in the model. An annual discounting rate of 3.5% was used in cost-effectiveness analysis. Main Outcomes and Measures: Proportion of new TB cases averted above base case scenario, discounted quality-adjusted life-years gained (QALYG), incremental cost, and incremental cost-effectiveness ratios in 2017 to 2023. Results: A total of 3130 patients with HIV (2740 [87.5%] male and 2800 [89.5%] younger than 50 years at HIV diagnosis) with 16 630 person-years of follow-up data from 2002 to 2017 were analyzed. Of these, 94 patients (0.67 [95% CI, 0.51-0.91] per 100 person-years) developed TB. Model estimates of cumulative number of TB cases would reach 146 by 2023, with the annual number of new TB diagnoses ranging from 6 to 8. For patients who had negative LTBI test results at baseline, subsequent LTBI testing strategies were ranked by ascending effectiveness as follows: (1) no testing, (2) test by risk factors, (3) biennial testing for all, (4) up to 3 tests for all, and (5) annual testing for all. Applying a willingness-to-pay threshold of $50 000 per QALYG, none of the subsequent testing strategies were cost-effective. Test by risk factors and up to 3 tests for all were cost-effective only if the willingness-to-pay threshold was increased to $100 000 per QALYG and $200 000 per QALYG, respectively. More new TB cases would be averted by expanding LTBI testing and/or treatment coverage. Conclusions and Relevance: Changing the current testing strategy to less intense testing strategies is likely to be cost-effective in the presence of an increased coverage of baseline LTBI testing and/or treatment.

CANADA; HONG Kong (China); TUBERCULOSIS prevention; CONFIDENCE intervals; COST effectiveness; HIV-positive persons; LONGITUDINAL method; MEDICAL screening; RESEARCH; RESEARCH funding; STATISTICAL sampling; TUBERCULIN test; RETROSPECTIVE studies; QUALITY-adjusted life years; DATA analysis software; STATISTICAL models; DESCRIPTIVE statistics; INTERFERON gamma release tests; MIXED infections

JAMA Network Open, 2019, Vol 2, Issue 9, pe1910960

2574-3805

Academic Journal

10.1001/jamanetworkopen.2019.10960