COST-EFFECTIVENESS OF RAPID DIAGNOSTICS AND CARE SYSTEMS IMPROVEMENTS FOR TUBERCULOSIS IN INDIA

Purpose: Over two million individuals have active tuberculosis (TB) in India, and its public treatment system faces two challenges: 1) multi-drug resistant (MDR) TB; and 2) inadequate diagnosis and treatment in the private sector. New rapid and accurate diagnostic systems (e.g., GeneXpert) that can detect drug resistance may help address these challenges, although test costs would rise. It is unclear whether GeneXpert should be used to diagnose suspected TB cases or simply replace drug susceptibility tests for patients not responding to treatment. Additionally, pilot programs where patients are referred from private to public sector clinics (pubic private mix, or PPM) have demonstrated the ability to accelerate the time to accurate diagnosis and treatment. We evaluated the cost-effectiveness of these improvements used alone or in combination. 

Method: We extended a dynamic transmission microsimulation model of Indian TB. Individuals were stratified by age, sex, and TB, drug resistance, and treatment status. We calibrated the model to Indian demographic, epidemiologic, and TB public and private healthcare trends.  We estimated costs by analyzing health consumption expenditure survey data supplemented with published literature. We developed a novel method to accurately project lifetime costs and QALYs beyond a ten-year policy analysis horizon. Interventions included: (1) replacing drug susceptibility testing with GeneXpert; (2) replacing smear and culture with GeneXpert to diagnosis TB and drug resistance; (3) implementing nationwide PPM with imperfect effectiveness; and combinations of (3) with either (1) or (2). Costs (reported in 2012 USD) and QALYs were discounted at 3% annually.

Result: GeneXpert for TB and drug susceptibility testing increased costs by $2,484,000 and gained 2,120 QALYs per 100,000 people relative to the status quo. The combination of PPM and GeneXpert used for drug susceptibility testing increased costs $145,000 and gained 1,480 QALYs per 100,000 people. GeneXpert for both TB and drug susceptibility testing cost $3,655 per QALY relative to the combination of PPM-GeneXpert for drug susceptibility testing, which cost $197 per QALY relative to GeneXpert for drug susceptibility testing alone.

Conclusion: In India, new TB diagnostic technologies and care system improvements provide good value for money. Rapid TB and drug susceptibility testing provide benefits at costs below 3-times India’s per-capita GDP. The combination of PPM with rapid drug susceptibility testing provides benefits at costs below 1-time per-capita GDP.