Effective management of drug-resistant tuberculosis (DR-TB) hinges on timely and accurate detection. A recent study evaluated DR-TB diagnostic cost-effectiveness in high-burden settings, comparing rapid molecular assays with traditional phenotypic drug susceptibility testing (pDST). Rapid diagnostics represent a vital shift away from slower, conventional methods that often delay life-saving treatments.

The research utilized a decision-analytic model to simulate outcomes for patients with microbiologically confirmed TB. Consequently, the study assessed nine distinct diagnostic strategies, including Line Probe Assays (LPAs), Xpert MTB/XDR, and targeted next-generation sequencing (tNGS). The evaluation measured health benefits through disability-adjusted life-years (DALYs) and incremental cost-effectiveness ratios (ICERs).

Analyzing DR-TB diagnostic cost-effectiveness

Results indicated that the strategy of 'Xpert followed by Xpert XDR plus pDST' was the most cost-effective option. This approach yielded an ICER of USD 6,554 per DALY averted, which falls comfortably below South Africa's GDP per capita threshold. Although tNGS paired with pDST provided the greatest overall health benefits—including the lowest mortality—its high cost (USD 25,918/DALY averted) currently limits its routine implementation.

Furthermore, diagnostic replacement scenarios showed that tNGS alone could be cost-effective where pDST is unavailable. Therefore, clinicians and policymakers in high-burden regions like India must prioritize integrated molecular testing. These tools facilitate early treatment initiation, which significantly reduces transmission and improves patient survival rates. Notably, the study confirms that molecular diagnostics offer an optimal balance of speed and economic efficiency.

Frequently Asked Questions

Which TB diagnostic strategy is most cost-effective?

Combining Xpert MTB/RIF with Xpert MTB/XDR and phenotypic testing is the preferred strategy. It provides high diagnostic accuracy and early treatment initiation while remaining within common economic thresholds in high-burden countries.

Is next-generation sequencing viable for TB in resource-limited settings?

Targeted next-generation sequencing (tNGS) offers superior clinical outcomes but remains expensive. It is currently most viable as an alternative where phenotypic testing is inaccessible or for specific high-risk populations.

How do rapid molecular tests improve DR-TB outcomes?

These tests drastically reduce the time to diagnosis for resistance to isoniazid and fluoroquinolones. Consequently, patients receive the correct treatment regimen much faster than through traditional culture-based methods.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice and is not a substitute for professional clinical judgment. Refer to the latest local and national guidelines for clinical practice.

References

Fekadu G et al. Optimizing drug-resistant tuberculosis diagnosis: cost-effectiveness of rapid molecular and phenotypic assays in South Africa. BMC Med. 2026 Feb 09. doi: 10.1186/s12916-026-04693-3. PMID: 41664022.

World Health Organization. WHO consolidated guidelines on tuberculosis: Module 3: Diagnosis - Rapid diagnostics for tuberculosis detection. 3rd Edition. Geneva: WHO; 2024.

Mehra R et al. Economic evaluation of diagnostic pathways for drug-resistant tuberculosis in high-burden settings. Indian J Med Res. 2025;161(2):142-155.