Griffin is an epidemiologist who is an expert in gun violence and motor-vehicle related deaths and injuries. His research has examined gun-related mortality rates and ways to reduce the rates. He also studies mortality rates from motor vehicle and consumer product-related injuries and is able to provide insights on how to prevent these deaths and injuries.

His recent work has focused on ways to improve clinical care of trauma and burn patients, as well as discovering and treating acute kidney injury in newborns.