Epiville

Quizzes

Quiz 2, Module Ecological

2. Given that you are conducting an ecological study, define the source population from which you intend to draw the two comparison groups.

  1. Individual residents of Epiville who were recently diagnosed with Susser Syndrome
  2. All Epiville residents
  3. One study population should be all Susser Syndrome cases residing in Epiville; the comparison population should be healthy Epiville residents.
  4. The study population should be comprised of Epiville residents who are serviced by either the Rothman or Greenland Reservoirs.
Answer (a) — incorrect: Recall that we are undertaking an ecological study and are thus concerned with populations and not individuals.
Answer (b) — incorrect: This is not specific enough and only defines one study population. We are looking for two populations that we could compare.
Answer (c) — incorrect: These definitions are too specific and more appropriate for a case-control design.
Answer (d) — correct: This definition provides us with two study groups coming from the same source population. This will allow us to compare the incidence proportion of Susser Syndrome in the two areas using the two different sources of reservoir water.