My research interest involves using epidemiological studies to assist control and prevention of tuberculosis. I have been studying risk factors of tuberculosis, including active smoking and passive smoking, indoor and ambient air pollution, alcohol use, and diabetes, using population-based cohort studies and meta-analysis. Building on evidence from these epidemiological studies and epidemic theory of infectious diseases, I am investigating population-level impact of changing risk factors on future tuberculosis epidemiology, the interaction between chronic disease epidemiology and tuberculosis epidemiology, and methodological issues when conducting such studies. I also used  epidemic models to assess the potential impact of tuberculosis interventions that are being considered by policy makers, including new diagnostics (e.g., LED microscopy, Gene Xpert MTB/RIF) in developing countries and tuberculosis control programs (active case finding and treatment of latent tuberculosis infection) in Taiwan. Our team is currently conducting a large population-based tuberculosis cohort study combining whole genome sequencing, routine public health information, and geographic information system to understand the transmission of drug-susceptible and drug-resistance tuberculosis in Taiwan. We also involved in investigating the transmission dynamics of COVID-19 and evaluating the effectiveness of case-based and population-based interventions for COVID-19 in Taiwan. I am also interested in applying the framework of Comparative Risk Assessment and have extended it to a time-based approach when we evaluated the impact of respirable pollutants on major lung diseases in China.