Question
An epidemiologic investigation that was started on January 1, 2011, identified a population of 1,000 individuals among whom 4 were found to have the disease under study. During the year of the study, six new cases were found. Among the total of 10 cases, there were 6 deaths during the year. For the 10 cases, the diagram indicates the time of case recognition, periods of observation during the study, and vital status at the time of the termination of observation. An arrow at the start of the diagram (subjects 1, 2, 3, 4) indicates that the start of disease occurred before the study began. Assume that the 990 remaining individuals in the study did not become ill or die during the year of observation. From the information and diagram given, calculate the following:
A. Prevalence of the disease on January I, 2011; July I, 2011; and December 31, 2011
B. Cumulative incidence of disease during 2011
C. Cumulative incidence of death during 2011
