Problem
For each of the following scenarios answer the questions about bias that follow. Use complete sentences
Childhood dental x-rays and thyroid cancer
A case-control study was conducted to assess the association of childhood dental x-rays and thyroid cancer. Newly diagnosed individuals with thyroid cancer (cases) were compared with random sample of individuals without thyroid cancer (controls) in regard to dental x-rays as a child.
1. Which type and mode of bias could be introduced into this study?
2. Why do you suspect the presence of the bias you have identified?