Question

II. Use the information provided below to answer the following questions:

1)You are interested in studying the relationship between exposure to methylmercury (MeHg) (which occurs mostly from consumption of contaminated seafood) and coronary heart disease (CHD) in the general population. You conduct a study where you recruit 30,000 population-based (i.e. not incarcerated or residing in an assisted living facility) older adults (age 65+ years) free of CHD, measure MeHg in their blood and follow them up for 10 years. Your study gives rise to the following data (assume no loss to follow-up):

a. What type of study have you conducted? [2 pts]

b. What is one advantage of using this study design in this situation? [2 pt]

question #2 Measuring MeHg in blood is expensive and you realize that you could employ a more efficient study design. Instead of following 30,000 people for 10 years, you could have used existing data from a similar study of 10,000 participants. With these data, you can assess exposure to MeHg (using history of high seafood consumption from source known to have high levels of MeHg that was previously collected) for cases [CHD] (n=5,000) and an equal number of controls (n=5,000). (Participants in this study have the same distribution of MeHg exposure as your original cohort).

4. What type of study would you have conducted? [2 pts]

5. What are two advantages to conducting this study versus the larger study described previously? [4 pts]

8. Mention one important limitation you could face running the latter study? [2 pts]

Answer 1

Answer #1.

A. Census

B. The chance or error is very low. Here we get exact value (no estimated value).

Answer #2.

4. Design of Experiments

5. The two advantages of this study are:

First, It saves money, efforts and man power.

Second, the past data saves times also.

8. Since here we are using only 10000 data instead of 30000, so there is a chance of error that could occur. It may differ from the actual value