Langa's research has made substantial contributions to understanding the
epidemiology, risk factors, outcomes, and societal impacts of cognitive aging and
dementia. His work combines rigorous population science with clinical insight to inform policies and interventions aimed at improving the health and well-being of older adults. Much of his research is conducted through and alongside the Health and Retirement Study (HRS), the largest and longest-running nationally representative longitudinal study of U.S. adults—and its international partner studies. A 2013 front-page
NY Times article reported that the HRS is "considered a gold standard among researchers on aging issues." Langa has made significant contributions to the world-wide growth of the
Health and Retirement Study (HRS) model of population studies. There are currently more than thirty-five countries that field surveys modeled on the HRS and Langa is a co-investigator or consultant to many of those studies. Langa's work is often cited as part of US public policy deliberations, including a 2023
NY Times series on the need for major reforms of the US long-term care system. A central focus of Langa's work is measurement of cognitive function and
dementia in population studies, including development and implementation of the Harmonized Cognitive Assessment Protocol (HCAP), which harmonizes in-depth cognitive assessments across different countries to allow valid cross-national comparisons. He has published methodological papers describing the design,
psychometric properties, and cross-country applications of HCAP¬-based cognitive batteries. Langa's substantive research includes national estimates of dementia prevalence and mild cognitive impairment in older Americans using HRS and HCAP data, documenting how these burdens vary by age, race, education, and socioeconomic status. His studies in leading journals have also examined trends over time and disparities in cognitive outcomes. Langa was the senior author on two of the most-widely cited papers that use HRS data, including a study led by Dr. Jack Iwashyna on the long-term physical and cognitive outcomes associated with sepsis published in JAMA in 2010, and a study of the economic cost of dementia in the US led by Professor Michael Hurd published in the
New England Journal of Medicine in 2013. He has investigated risk and protective factors for cognitive decline and dementia, including cardiovascular risk profiles, acute illnesses such as sepsis or stroke, genetic and lifestyle influences, and health behaviors, producing widely cited findings on lifestyle, genetic risk, and dementia incidence. Langa's work further explores the social, economic, and health-system consequences of aging and
cognitive impairmentt, including the costs of
Alzheimer's disease and related dementias, financial impacts on individuals and families, and patterns of health-care utilization among older adults. In addition to his dementia research, he collaborates on international and comparative studies of aging, including cognitive health differences across countries, and adaptations of cognitive measures in diverse settings such as rural Kenya. == Awards and honors ==