SYNERGIES IN OUTCOMES FROM PUBLIC AND PRIVATE SECTOR TB AND MDR TB CONTROL INTERVENTIONS: AN INDIAN MICROSIMULATION MODELING STUDY

Purpose: Despite India’s nationwide public sector tuberculosis (TB) control program, many patients seek and receive care in private sector clinics. Private sector care often includes inappropriate diagnostics and ineffective treatments of insufficient duration that can select for multidrug resistant (MDR) TB. Given current efforts to improve TB care and roll out new technologies, we evaluate likely impacts of these efforts if undertaken in the public and private sectors separately or in combination.

Method: We extend our previously developed, dynamic transmission microsimulation model of TB in India. The model follows India’s population stratified by age, sex, TB, drug resistance, and treatment status. We calibrate the model to Indian demographic, epidemiologic, and TB healthcare patterns in the public and private sectors. Control interventions include: 1) improving treatment effectiveness in the public sector only; 2) improving the accuracy and rapidity of TB diagnosis and drug sensitivity testing in the public and/or the private sector; 3) increasing referrals from the private sector to the public sector through public private mix (PPM); 4) reducing inappropriate medication use to prevent MDR generation in the private sector; 5) combinations of these efforts. Main outcomes are incidence and prevalence of active non-MDR and MDR TB in 2023 relative to 2013 levels.

Result: Without interventions, the model projects declines in non-MDR TB incidence (12%) and prevalence (12%) and increases in MDR incidence (15%) and prevalence (19%) between 2013 and 2023. For non-MDR TB, increasing referrals from the private to the public sector (through PPM) alone or in combination with improved diagnostics yields 15-17% lower incidence and 34-47% lower prevalence. Synergies provided by combined public and private sector interventions are evident for MDR outcomes. Exclusively private sector interventions result in MDR incidence and prevalence increases of 13-16%, whereas exclusively public sector interventions result in 2-7% declines. Combinations of PPM and increases in non-MDR TB treatment effectiveness to avoid generating MDR reduce incidence by 13-19%. Likewise, although MDR prevalence increases 14-18% with PPM alone, PPM combined with rapid, accurate diagnostics results in MDR prevalence declines of 55-58%.

Conclusion: Combining public and private sector interventions to improve and link TB care and rapid, accurate diagnostics is a promising approach for reducing non-MDR and MDR TB in India.