Epidemiology for Public Health Practice 5th Edition by Robert Friis,Thomas Sellers

تمرين 7

You are investigating the role of physical activity in heart disease, and your data suggest a protective effect. While presenting your findings, a colleague asks whether you have thought about confounders, such as factor. Under which of the following conditions could this factor have confounded your interpretation of the data?
A) It is a risk factor for some other disease, but not heart disease.
B) It is a risk factor associated with the physical activity measure and heart disease.
C) It is part of the causal pathway by which physical activity affects heart disease.
D) It has caused a lack of follow-up of test subjects.
E) It may have blinded your study.