Questions 13-20. A 24-month prospective cohort study was done to examine the association between oral contraceptive use (OCP) and the development of deep vein thrombosis (DVT) among 800 women of child-bearing age. There were no losses to follow up but not all women were enrolled during the first month of the study, so each of them was followed-up for variable 3 period. The following results were obtained. Answer the questions based on the table below. (16 points) Number of participants enrolled Total Person Months Number of new DVT cases by 24 months at baseline OCP Use Yes 500 6600 90 No 300 3800 40 Total 800 10400 130 13. Calculate the 24-month cumulative incidence of DVT (per 100 persons) for those who used OCP. (2 points) 14. Interpret the 24-month cumulative incidence of DVT calculated in the previous question. (2 points) 15. Calculate the risk ratio for DVT among exposed and unexposed women. (2 points) 16. Interpret the risk ratio for DVT calculated in the previous question. (2 points) 17. Calculate the incidence density of DVT (per 100-person months) for those who did not use OCP. (2 points) 18. Interpret the incidence density of DVT calculated in the previous question. (2 points) 19. Calculate the rate ratio for DVT among exposed and unexposed women. (2 points) 20. Interpret the rate ratio for DVT calculated in the previous question. (2 points) Questions 13-20. A 24-month prospective cohort study was done to examine the association between oral contraceptive use (OCP) and the development of deep vein thrombosis (DVT) among 800 women of child-bearing age. There were no losses to follow up but not all women were enrolled during the first month of the study, so each of them was followed-up for variable 3 period. The following results were obtained. Answer the questions based on the table below. (16 points) Number of participants enrolled Total Person Months Number of new DVT cases by 24 months at baseline OCP Use Yes 500 6600 90 No 300 3800 40 Total 800 10400 130 13. Calculate the 24-month cumulative incidence of DVT (per 100 persons) for those who used OCP. (2 points) 14. Interpret the 24-month cumulative incidence of DVT calculated in the previous question. (2 points) 15. Calculate the risk ratio for DVT among exposed and unexposed women. (2 points) 16. Interpret the risk ratio for DVT calculated in the previous question. (2 points) 17. Calculate the incidence density of DVT (per 100-person months) for those who did not use OCP. (2 points) 18. Interpret the incidence density of DVT calculated in the previous question. (2 points) 19. Calculate the rate ratio for DVT among exposed and unexposed women. (2 points) 20. Interpret the rate ratio for DVT calculated in the previous question. (2 points)