Question

1. Groups that are selected for an ecologic study might be residents of a particular:               

A.    State

B.    County

C.    Census tract

D.    All of the above

2. Increases and decreases in the frequency of a disease within a year or over several years are known as:

A.    Secular trends

B.    Cyclic trends

C.    Point epidemic

D.    Clustering

3. Which factor(s) distinguish study designs from one another?

      A. Data collection methods

      B. Unit of observation

      C. Timing of data collection

      D. All of the above

4. An erroneous inference that may occur because an association observed between variables on an aggregate level does not necessarily reflect the association at an individual level is known as an:

A.    Ecologic Association

B.    Ecologic correlation

C.    Ecologic fallacy

D.    None of the above

5. Subjects are classified according to their exposure to a factor of interest and then are observed over time to document the incidence of disease in what type of study?                                             

A.    Prospective cohort study

B.    Case-control study

C.    Cross-sectional study

D.    Retrospective cohort study

6. Randomized controlled trials contain which of the following components?                    

A.    Rigorous inclusion and exclusion criteria

B.    Blinding or masking to prevent bias

C.    Comparable measurement of outcomes in treatment and control conditions

D.    All of the above

Answer 1