Explore This Program


The Massachusetts General Hospital Program in Pulmonary and Critical Care Population Health Research comprises faculty leading innovative research to improve the health of populations and inform policy in the U.S. and globally. Their work spans a variety of population health research areas, including equitable health care delivery, growing disease burden due to environmental and infectious exposures, and precision medicine. They collaborate with other investigators at Mass General, Harvard Medical School, Harvard T.H. Chan School of Public Health, and institutions around the world. Learn more about each faculty member’s research below.

Meet the Faculty

Lisa Bebell, MD, MScLisa Bebell, MD, MSc 

Dr. Lisa Bebell is an assistant professor at Harvard Medical School, associate in Medicine in the Mass General Division of Infectious Diseases and a research faculty member of the Medical Practice Evaluation Center. She is an adult Critical Care Medicine and Infectious Diseases specialist and devotes most of her time to research on infections in pregnancy and their impact on child health outcomes. In her work, Dr. Bebell partners with Drs. Joseph Ngonzi, Elias Kumbakumba, and Julian Adong at the Mbarara University of Science and Technology in Uganda. Dr. Bebell also works closely with Adeline Boatin, MD, MPH, and has partnered on antimicrobial resistance projects with Peggy S. Lai, MD, MPH, and Dr. Ngonzi. She can be followed on Twitter at @lisa_xpond. Please see Dr. Bebell’s Harvard Catalyst Profile for selected publications.

Laura Brenner, MDLaura Brenner, MD

Dr. Brenner’s research program is focused on using precision medicine and multiomic techniques to understand the basis of diseases, their mechanisms, and their endotypes, and utilize precise treatments that are individualized to each person and disease subtype. Her research spans multiple fields, including genetics, pharmacogenomics, the microbiome, and risk scores, to advance how we understand and treat complex diseases such as diabetes, COVID-19, cystic fibrosis, and more. One of Dr. Brenner’s projects is studying how the microbiome is affected by glycemic control in cystic-fibrosis-related diabetes (CFRD), specifically how the microbiome is influenced by patients’ glycemia and how change in glycemia can influence the microbiome. Additionally, Dr. Brenner was involved in multiple studies evaluating pharmacogenomics in diabetes, and she is the clinical primary investigator for a clinical study that recently finished enrollment, SCRAMBLED-EGGS- MMTT, which studies how response to a meal is influenced by genetics, metabolomics and proteomics. Dr. Brenner also leads a project that analyzed the overlap of glucocorticoid and diabetes genes, as well as a determination of how diabetes genetics influences the risk of glucocorticoid-induced hyperglycemia (GIH). With the COVID-19 pandemic, Dr. Brenner was involved in multiple research protocols to investigate what host characteristics lead to COVID-19 morbidity and mortality.

David Christiani, MD, MPHDavid Christiani, MD, MPH

The major research interests of the Christiani Lab are to understand the interactions and impact of environmental exposures and genetics on health and disease. This research is part of a field known as molecular epidemiology. Dr. Christiani has been active in developing new methods for assessing health effects after exposure to pollutants, incorporating genetic studies in environmental health and introducing genetic studies into the critical-care setting. He has also led or co-led multiple international collaborative studies in Asia, Africa, and Latin America.

Maha Farhat, MDMaha Farhat, MD

Dr. Farhat's research focuses on the development and application of methods for associating genotype and phenotype in infectious disease pathogens, with a strong emphasis on translation to better diagnostics and surveillance in resource-limited settings. To date, Dr. Farhat's work has focused on the pathogen Mycobacterium tuberculosis and spans the spectrum from computational analysis to field studies. She is principal investigator and co-investigator on several large projects funded by the NIH, including the National Institute of Allergy and Infectious Diseases (NIAID) and the Big Data to Knowledge (BD2K) initiative.

Vanessa Kerry, MD, MScVanessa Kerry, MD, MSc

Dr. Kerry’s research advances capacity in human resources for health (HRH) with the goal of equitable and quality healthcare delivery for all. Geographically, she has focused most prominently on sub-Saharan Africa, which has 24% of the global burden of disease but only 3% of the world’s healthcare workforce. Dr. Kerry co-founded and directs Seed Global Health, a non-profit that collaborates with public partners to build strong health systems founded on a robust workforce. Seed helps to expand and strengthen the quality of direct care, mentor for health leadership, and provide training for existing and future generations of health professionals. Seed’s implementation work, alongside its global policy engagement, serves as Dr. Kerry’s laboratory for original contributions to investigation, to support design of metrics for HRH and its impacts on other sectors, as well as for policy and advocacy efforts. Dr. Kerry’s work is now deeply focused on health system strengthening to meet the growing disease burdens in the face of climate change.

Peggy S. Lai, MD, MPHPeggy S. Lai, MD, MPH

The Lai Lab focuses on clinical and translational research at the intersection of environmental exposures, the microbiome, and lung health. Examples of ongoing research projects include the school microbiome and asthma, school virome and respiratory viral infections in children, effect of supplemental oxygen on the airway microbiome, contribution of fuel-based lighting to household air pollution in resource-limited settings, and additional critical care topics.

Crystal North, MD, MPHCrystal North, MD, MPH

Dr. North’s research focuses on understanding the influence of environmental and infectious exposures on lung health in resource-limited settings. She primarily studies the influence of ambient air pollution exposure on lung health among vulnerable populations, with a particular emphasis on people with HIV, women, and those with lower socioeconomic status. Her methods include environmental exposure assessment, observational cohort studies, and longitudinal health outcomes assessments. The goal of Dr. North’s research is to identify opportunities to improve the lung health of people living in resource-limited settings.

Krishna Reddy, MD, MSKrishna Reddy, MD, MS

Dr. Reddy studies tobacco, HIV, and tuberculosis, both individually and in combination. He applies methods of simulation modeling, epidemiology, and cost-effectiveness analysis to study clinical and economic outcomes in the U.S. and other countries. The goal of his research is to provide evidence- and model-based approaches to clinical decision-making and public health policy. Dr. Reddy is a faculty investigator in the Medical Practice Evaluation Center and the Tobacco Research and Treatment Center, both within the Mongan Institute at Mass General. His research is supported by the National Institutes of Health and the American Lung Association.

Christopher Worsham, MD, MPHChristopher Worsham, MD, MPH

Dr. Worsham is an Agency for Healthcare Research and Quality (AHRQ)-funded health services researcher at Mass General and the Harvard Medical School Department of Health Care Policy. He performs large database research using econometric methods, focusing on the use of natural experiments to study physician behavior, resource utilization, and healthcare policy, with special interest in the intensive care unit. Through his work, Dr. Worsham hopes to find opportunities to create higher value and more equitable healthcare for everyone.

Areas of Research

Environmental Health

  • David Christiani, MD, MPH
  • Vanessa Kerry, MD, MSc
  • Peggy S. Lai, MD, MPH
  • Crystal North, MD, MPH

Global Health

  • Lisa Bebell, MD, MSc
  • David Christiani, MD, MPH
  • Maha Farhat, MD
  • Vanessa Kerry, MD, MSc
  • Peggy S. Lai, MD, MPH
  • Crystal North, MD, MPH
  • Krishna Reddy, MD, MS

Health Services and Outcomes

  • Vanessa Kerry, MD, MSc
  • Krishna Reddy, MD, MS
  • Christopher Worsham, MD, MPH

Modeling and Cost-effectiveness Analysis

  • Krishna Reddy, MD, MS

Molecular Epidemiology and Precision Medicine

  • Laura Brenner, MD
  • David Christiani, MD, MPH
  • Maha Farhat, MD

Select Publications

Du M, Garcia JGN, Christie JD, Xin J, Cai G, Meyer NJ, Zhu Z, Yuan Q, Zhang Z, Su L, Shen S, Dong X, Li H, Hutchinson JN, Tejera P, Lin X, Wang M, Chen F, Christiani DC. Integrative omics provide biological and clinical insights into acute respiratory distress syndrome. Intensive Care Med. 2021 Jul;47(7):761-771. doi: 10.1007/s00134-021-06410-5. Epub 2021 May 25. PMID: 34032881; PMCID: PMC8144871.

Kerry VB, Ahaisibwe B, Malewezi B, Ngoma D, Daoust P, Stuart-Shor E, Mannino CA, Day D, Foradori L, Sayeed SA. Partnering to Build Human Resources for Health Capacity in Africa: A Descriptive Review of the Global Health Service Partnership's Innovative Model for Health Professional Education and Training From 2013-2018. Int J Health Policy Manag. 2022 Jul 1;11(7):919-927. doi: 10.34172/ijhpm.2020.228. Epub 2020 Nov 29. PMID: 33300760; PMCID: PMC9808199.

North CM, MacNaughton P, Lai PS, Vallarino J, Okello S, Kakuhikire B, Tsai AC, Castro MC, Siedner MJ, Allen JG, Christiani DC. Personal carbon monoxide exposure, respiratory symptoms, and the potentially modifying roles of sex and HIV infection in rural Uganda: a cohort study. Environ Health. 2019 Aug 20;18(1):73. doi: 10.1186/s12940-019-0517-z. PMID: 31429759; PMCID: PMC6701123.

Reddy KP, Gupta-Wright A, Fielding KL, Costantini S, Zheng A, Corbett EL, Yu L, van Oosterhout JJ, Resch SC, Wilson DP, Horsburgh CR Jr, Wood R, Alufandika-Moyo M, Peters JA, Freedberg KA, Lawn SD, Walensky RP. Cost-effectiveness of urine-based tuberculosis screening in hospitalised patients with HIV in Africa: a microsimulation modelling study. Lancet Glob Health. 2019 Feb;7(2):e200-e208. doi: 10.1016/S2214-109X(18)30436-4. PMID: 30683239; PMCID: PMC6370043.

Worsham C, Woo J, Jena AB. Birth Month and Influenza Vaccination in Children. N Engl J Med. 2020 Jul 9;383(2):184-185. doi: 10.1056/NEJMc2005928. PMID: 32640138; PMCID: PMC7386461.