Ecological studies and case reports (12 points)

Study design defines the way a study was developed and presented. Each study design has inherent potential biases.

1. You are planning to conduct an ecologic study. For this study, please answer the following questions. (1) What two factors (based on group data) would you compare, and where might you acquire the data? (2) What do you hypothesize the results will show? Will it be a positive or negative association? (3) What potential bias might there be in your study? (only list one or two biases) (6 points)

For example, I might want to look at the association between the following two factors:

1. Factor 1= Number of Pizza Hut restaurants, stratified by state. I may be able to find the number of restaurants per state on the Pizza Hut website.

Factor 2= Incidence of breast cancer in females, stratified by state. These data might be found on the National Cancer Institute website.

1. Hypothesis= I hypothesize that a higher number of Pizza Hut restaurants by state is associated with a lower incidence of breast cancer by state.
2. Potential bias= The restaurant data may be for the current year but the incidence of cancer may be for a previous year, causing me to compare different time points for the two factors of interest.