Karim’s research areas of interest are in the advancing of statistical methodology, and the use of mathematical models and computer simulations to understand the behavior of complex systems. These two general interests are complementary to one another; mathematical modeling and computer simulation represent a data-generating process which can be analyzed through the use of various statistical methodologies, while advances in statistical methodologies are needed to inform and parameterize computer simulations as the data-generating processes become increasingly complex. He has pursued these general interests across multiple domains of study with a particular focus on transmission and infection due to antimicrobial resistant organisms in healthcare facilities, particularly with respect to understanding how to improve patient outcomes by reducing rates of healthcare-associated infections and gaining deeper insights into the key factors that result in infection.