Foodborne epidemiologists at the local health departmentinvestigated an outbreak of food poisoning at a Cinco de Mayopotluck dinner. Initially the epidemiologists determined thatnachos were the cause of the outbreak. However, upon closer reviewlettuce was determined to be the true cause of the outbreak.
6a. In this example, would you expectlettuce to act as a positive or negative confounder on therelationship between nachos and food poisoning? Explain youranswer.
6b. Assume that you want to analyze the association betweennachos and food poisoning. Provide a method to control for theconfounder lettuce in the design of your study. Please bespecific.
