9 8 (3 marks): Assuming a diagnostic test with Sensitivity 80%, Specificity 60%, calculate two positive predictive values, with 21% prevalence and then with 31% prevalence assuming a total number of 4500 people who were screened. Tip: First draw and label TWO 2x2 tables (you will need two tables, one with 21%prevalence and one with 31% prevalence & then calculate positive predictive value from each table). Each table is worth 1 mark each with 0.5 mark for each PPV. Question 9 (3 marks): Cervical cancer screening program was introduced for Human Papilloma Virus in a community. A total of 6712 women aged 18 years and over were screened and 132 were identified to have HPV at baseline. During the follow up period of next three years 53 new cases of cervical cancer were diagnosed. Among the 132 cases at baseline, 13 died at the end of first year, 19 died at the end of second year while 5 died at the end of final year of the follow up. Seventy-six deaths were also recorded among non-cases and all these happened in the final year of the follow up. Apart from the deceased everyone else completed the follow up. Please calculate and interpret: . Point prevalence at the end of the follow up period. . Period Prevalence over the follow-up. . Annual cumulative incidence