Q 4 Imagine you have the following results from a case control study, stratified on 2 levels of some characteristic: Stratum 1 OR = 0.333 Stratum 2 OR = 0.999 Crude OR = 0.8 These results are most consistent with the characteristic being Select one: Q a. Neither a confounder nor an effect modifier O b. A confounder, but not an effect modifier O c. An effect modifier Q d. A bias 05 A researcher gave a questionnaire on past exposures to pesticide to a group of people who had recently been diagnosed with pancreatic cancer and to another group of people who were cancer free. is an example of a/an Select one: Q a. Case-control study O b. Crosssectional study 0 c. Ecological study 0 d. Retrospective cohort study 0 e. Prospective cohort study