Cost and impact of decentralized tuberculosis testing: a modeling analysis of price thresholds for molecular instruments in high-burden settings.

BACKGROUND: Despite progress in reducing global tuberculosis (TB) incidence, ongoing funding disruptions threaten to reverse gains. Timely, accurate diagnosis integrated with rapid treatment is critical to reducing morbidity, mortality, and transmission-but remains costly, particularly for decentralized approaches. As global health budgets tighten, identifying the optimal cost for molecular TB diagnostics instruments is critical to inform scale-up decisions.

METHODS: We developed a probabilistic patient pathway model to assess the cost-effectiveness of decentralizing TB testing across primary healthcare facilities in high-burden settings. Scenarios varied by facility testing density (low, medium, high) and anticipated testing volume increases (none, partial, full). We included the effects of instrument downtime and calculated the maximum instrument + warranty prices at which fully decentralized testing would be considered cost-effective at a $500/disability-adjusted life year (DALY) averted threshold.

FINDINGS: Decentralization with increased testing averted up to 23% more DALYs than centralized testing but was not cost-effective at current instrument + warranty prices. Partial decentralization to the largest 20% of facilities approached cost-effectiveness (<$1000/DALY) with full testing increase. For full decentralization to meet the $500/DALY threshold, maximum viable instrument + warranty prices for low-throughput instruments ranged from $0 (no uptake increase) to $410-$6048 (increased testing uptake, low- to high-testing density settings).

INTERPRETATION: At current prices, decentralized molecular TB testing is unlikely to be cost-effective, even with improved uptake, systemwide. However, meaningful reductions in instrument + warranty costs could make both full and partial decentralization viable. As countries face tighter budgets, clear price targets for cost-effectiveness can help guide procurement and investment decisions in TB diagnostics.

FUNDING: BMGF, Willem Bakhuys Roozenboomstichting.