Ecological Study


Step 4: Study Design

(To answer the following multiple choice and data analysis questions, please refer to Gordis, pgs. 185-187)

The first step of your investigation is to generate a solid hypothesis. Once again, you look over the information that you have gathered regarding the Susser Syndrome cases and the reservoirs in Epiville. The data you have is at the population level. Consequently, you decide to conduct an ecological study.

1. Based on the facts presented, which of the following would be the most appropriate hypothesis to investigate in this ecological study?
checkbox a. Residents of Epiville are at a higher risk of developing Susser Syndrome than residents of the neighboring towns.
checkbox b. Employees of the Porks-A-Lot pig farm have a greater risk of developing Susser Syndrome than the general population of Epiville.
checkbox c. The population served by the Rothman Reservoir has a higher incidence rate of Susser Syndrome than does the population served by the Greenland Reservoir.
checkbox d. Those diagnosed with Susser Syndrome will have greater odds of being a Porks-A-Lot employee than those without Susser Syndrome.

You and your supervisor agree on the hypothesis. Now, in order to be thorough, you must clearly define who is to be eligible for the ecological study.

2. Which population will be the source population for the study, given that this is an ecological study?
checkbox a. Individuals should be diagnosed with Susser Syndrome and be residents of Epiville.
checkbox b. The study population should be that of Epiville residents.
checkbox c. One study population should be comprised of Susser Syndrome patients residing in Epiville; a second population should be comprised of healthy Epiville residents.
checkbox d. The study population should be comprised of Epiville residents who are serviced by either the Rothman Reservoir or by the Greenland Reservoir. Furthermore, Susser Syndrome patients should have come from this underlying population.

With your hypothesis and source population defined, you must now determine from exactly where the data will come from and how it should be collected.


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