Evidence-Based Dentistry

Case Control Studies Studies that make observations about possible associations between the disease of interest (lung cancer) and one or more hypothesized risk factors (tobacco use). Case control studies are retrospective in that subjects already have a certain disease or condition and are compared with a representative group of disease-free persons (controls) from the same population.

Case Reports A description of a single patient case report. These are observations and do not use a control group with which to compare outcomes.