Quiz 7, Module Case-control
7. Given the study design, what is the best way to define the exposure variable?
- Directly observe the consumption of EnduroBrick or Quench-It at the Superfit Fitness Center
- Question all study subjects as to their own assessment of EnduroBrick and Quench-It consumption using a standardized survey tool.
- Use the Superfit Fitness Center credit card billing system to identify exposure to EnduroBrick and Quench-It in the members.
Answer (a) —
incorrect:
This is a case-control study in which the exposure has already occurred. Study participants are enrolled based on their disease status, after which exposure is compared between those with the disease and those without the disease.
Answer (b) —
incorrect:
This is commonly employed and it is probably the fastest and cheapest method; however, it is problematic here as individuals may have difficulty recalling the amounts consumed over a 2- year period. In addition, now that the news is reporting a connection between Susser Syndrome and Superfit Fitness Center, the interviewee's responses may be differentially affected by their concerns over what they believe may be the cause of the condition
Answer (c) —
correct:
This will provide the most accurate assessment of exposure since it does not depend on the ability of the subject to recall their exposure. Furthermore, we know EnduroBrick and Quench-It are not available in retail stores, so there is no possibility of subjects consuming more than is recorded by the fitness center. (It is not perfect, however, as purchasing EnduroBrick and Quench-It is not a guarantee that the individual actually consumed it!!!)
