From Policy to Practice: Physician Decision Making, Patient Outcomes, and Policy Evaluation in Global Tuberculosis Control

Tuberculosis (TB) remains one of the world’s leading causes of infectious disease death, disproportionately affecting individuals living in low- and middle-income countries. While biomedical advances have improved diagnosis and treatment, persistent gaps in care reflect broader system-level, clinical, and policy challenges. This dissertation explores global TB control through three interconnected perspectives: physician decision-making, patient outcomes, and health policy evaluation, with a focus on real-world implementation in resource-constrained settings. Chapter 2 examines how clinicians decide to initiate TB treatment for individuals being evaluated for TB when bacteriological test results are negative. Using a systematic review and individual patient data meta-analysis from over 15,000 individuals across 13 countries, I identify factors—such as symptom profile, HIV status, and prior TB history—that influence treatment decisions. The findings highlight the complexities of diagnostic decision-making in resource-limited settings. Chapter 3 investigates long-term mortality among individuals diagnosed with TB in Brazil. Leveraging linked administrative data, I construct a retrospective cohort of over 700,000 individuals diagnosed with TB and compare their mortality risk to that of the general population over time. Results show elevated mortality persisting for many years after treatment, highlighting the importance of continued care and monitoring beyond the treatment period. Chapter 4 evaluates the potential health and economic impact of targeted active case finding (ACF) in Blantyre, Malawi, guided by community-level Mycobacterium tuberculosis immunoreactivity surveys. Using a simulation model, I compare survey-informed geographical targeting to untargeted ACF and passive case finding. Findings suggest that targeted ACF guided by immunoreactivity survey results can improve efficiency, particularly in settings with a high prevalence of undiagnosed TB and high HIV burden. Together, these chapters illustrate that advancing global TB control requires more than technical fixes—it demands engagement with clinical uncertainty, long-term patient needs, and the complexities of health system design. This dissertation highlights the importance of aligning diagnostic approaches, treatment pathways, and policy responses with both patient realities and system-level constraints, contributing evidence to support more responsive and equitable TB programs.