Posted: February 24th, 2017

What is the odds ratio for HPV exposure and cervical cancer among smokers only? (3 pts) A. 2.0 B. 1.4 C. 1.0 D. 3.9 E. Cannot be determined from these data.

Which of the following is an appropriate measure of association for a cross-sectional study? (2 pts) a. Incidence rate ratio b. Prevalence ratio c. Cumulative incidence ratio d. Risk difference

12. A relative risk of 1.0 is interpreted as: (2 pts) a. A protective association between the exposure and the disease b. A weak or moderate positive association between the exposure and the disease c. No association between the exposure and the disease d. Cannot be determined without knowing the specific exposure and the disease

13. Why do we age-standardize (age-adjust) incidence data to compare disease incidence between two different populations? Explain and give an example. (6 pts)

14. The tables below come from a case-control study of cervical cancer and test results for exposure to human papilloma virus (HPV).

Cervical Cancer No Cervical Cancer HPV positive 120 18 HPV negative 70 41

After stratifying the above data by smoking status, the following tables were obtained:

Cervical Cancer No Cervical Cancer Smokers HPV positive 100 10 HPV negative 25 5

Cervical Cancer No Cervical Cancer Non Smokers HPV positive 20 8 HPV negative 45 36

a. Before stratifying on smoking behavior, what is the overall odds ratio (OR) found by the study? (3 pts) A. 2.0 B. 1.4 C. 1.0 D. 3.9 E. Cannot be determined from these data.

c. What is the odds ratio for HPV exposure and cervical cancer among smokers only? (3 pts) A. 2.0 B. 1.4 C. 1.0 D. 3.9 E. Cannot be determined from these data.

b. Based on the data above, which statement describes the relationship between cervical cancer and HPV? (3 pts) A. Cervical cancer cases are more likely than controls to have been exposed to HPV. B. When stratified by smoking status, cervical cancer is not associated with HPV in either stratum. C. When stratified by smoking status, there is a stronger association between cervical cancer and HPV in smokers than in non-smokers. D. Cervical cancer is not associated with HPV. E. A cohort study must be done in order to describe the relationship.