Asthma is the most common chronic disease among children in Canada. It has several main causes that occur in utero and early in life. These ‘risk factors’ can be reduced through public health interventions that prevent asthma before it develops. Despite the opportunity to drastically reduce asthma in Canada, little progress has been made on asthma prevention due to a poor understanding of which interventions to invest in and when they should be applied. My objective is to provide high quality evidence to patients, providers and policy makers on how healthcare resources can best be used to prevent asthma in children. My research program will accomplish this objective using a computer simulation model of asthma (the Lifetime Exposure and Asthma Outcomes Projection [LEAP] model), which simulates the development and life trajectory of asthma. I will evaluate a series of preventative interventions that patients and knowledge users have identified as priorities, and determine their lifetime health benefits and impact on the healthcare system. I will work closely with patients, providers and policy makers to make sure the resulting policy recommendations are aligned with their values and can be implemented in healthcare systems.