India's private sector engagement model improved TB notification and drug uptake.

SETTINGS: Since 2018, India's National Tuberculosis Elimination Programme has adopted a patient-provider support agency (PPSA) model to engage the private sector using domestic resources. OBJECTIVE: To evaluate the effectiveness of the PPSA model for private-sector TB notifications, care services, and treatment success in 42 districts across six Indian states and to explore enablers and challenges of PPSA implementation. DESIGN: A mixed-methods study. We performed interrupted time-series analysis using the segmental regression model to quantify level and monthly changes in private sector TB indicators before (2019-2021) and after PPSA implementation (2021-2024) and interviewed stakeholders regarding enablers and challenges of PPSA implementation. RESULTS: PPSA initiation significantly increased private-sector TB notification rates (immediate change) from 43.5 in 2019 to 72.7 per 100,000 in 2021 and sustained till 2024. Similarly, number of private facilities notifying TB increased from 1,040 to 1,858 and prescription of free fixed dose combination drugs by private providers increased from <1% to 14%. These gains were not accompanied by improvements in other TB care services and treatment success. Stakeholders offered insights and reasons for these variations. CONCLUSION: The PPSA model improved notification and drug uptake and will require strengthening of quality-of-care services for future scale-up.