Abstract for: Expanding Diagnostic Testing for Drug-Resistant Tuberculosis in High-Burden Settings: A Cost-Effectiveness Analysis

Drug resistant tuberculosis (DR-TB) is a major public health concern. Current rapid diagnostics focus on detection of rifampicin-resistant TB, missing other forms of DR-TB. New diagnostic tools such as GeneXpert XDR and targeted Next-Generation Sequencing (tNGS) can detect a wider range of DR-TB and are shown to be cost-effective in low-burden settings. However, implementation data and cost-effectiveness of these diagnostic tools in high-burden TB settings is limited. A dynamic simulation model was calibrated to WHO-reported TB data for Philippines and Thailand from 2010 – 2019. Intervention scenarios for improved diagnostic testing of drug-resistance were simulated for 2025 – 2034. Health benefits were estimated using disability-adjusted life years (DALYs). Cost-effectiveness was calculated from a health system perspective using country-level TB diagnosis and treatment costs. Analyses include incremental cost-effectiveness ratios (ICERs) and incremental net monetary benefit (INMB). Implementing GeneXpert XDR or tNGS for DR-TB detection improves TB health outcomes. Scenarios using GeneXpert XDR are more likely to be cost-effective than scenarios using tNGS. Interventions targeting previously treated cases reduce costs but also reduce health benefits. Testing all TB cases with GeneXpert XDR is cost-effective (Philippines ICER = $1,808; Thailand ICER = $5,251). Targeting GeneXpert XDR to previously treated cases is also cost-effective but results in lower INMB. In high TB-burden countries, GeneXpert XDR is cost-effective as an additional DR-TB diagnostic test. Although targeted use of GeneXpert XDR among previously treated cases is cost-effective, application of GeneXpert XDR to all presumptive TB cases would maximize monetary benefits and provide greatest value for money. tNGS is not cost-effective for routine clinical DR-TB testing but has potential for application to high-risk populations, especially with introduction of new TB treatment regimens.