Please use the following diagram to answer questions 1-6 about the 7 subjects followed for 7 years. Assume that deaths of those with the disease were from the disease. Subject A 1 Year Beactine (start of study) 2 3 Years 0 Xane 7 End of Follow-up 1. How many people had the disease at the start of follow-up (year 0)? (100) 2 people including subject 3 and 6 had the disease at the start of follow up. 2. What is the prevalence of the disease at the start of follow-up? (100 The prevalence of disease at the start of the follow-up would be 2 out of 7 which would equate to 28% 3. How many incident cases of disease occurred during the follow-up period? (1 00 incident cases occur when there's a sudden new disease within a community. In this instance there would be 3 incident cases (subjects 1,4,7) during the period of follow up How many person-years did subjects 1-7 contribute to the study? (10) PUBH 2010 Homework. Incidence, Prevalence, & Person-Time 5. What is the incidence rate of this disease per 100 person-years? Per 1000 person- years? (1 pt) 6. What is the case fatality rate? (1 pt) Part 2. Page 2 of 2 7. List three factors which may affect a population's mortality. 8. Describe the three levels of prevention-primary, secondary, and tertiary. Give examples at each level which would be appropriate as part of a comprehensive program to prevent HIV (for more information on HIV, you can read Friis page 218, or review CDC's pages on HIV).