You implement a cohort study assessing the association between use of the diaphragm for contraception versus using the IUD and risk of acquiring HIV infection in Kenya. You start your study with 500 women in each arm and follow them for 24 months. At the end of the study, 100 women in the diaphragm arm were lost to follow-up, while only 30 women in the IUD arm were lost to follow-up. A. You decide to run analyses to compare the women who were lost to follow-up from the women who remained in the study. What types of variables would be of most interest to you in this comparison and why? (2 points) B. How would you interpret what you find in part A (i.e. if you find the groups are similar versus if you find the groups differ)? Why? (1 point) C. How could you attempt to adjust for loss to follow up during your data analysis? (1 point)
