5/9a. 0.050b. 0.0505c. 0.060d. 0.0606The correct answer is A. Prevalence is the proportion of the population with an existing disease (orcondition) at a particular time. Prevalence = #existing cases with disease/#individuals in studypopulation at a point in time. Plugging in the numbers in the problem above, on July 1, 2013:Prevalence= 500 cases/10,000 women = 0.050.Correct!Correct!1 / 1 ptsQuestion 5The local government of a small town in Massachusetts initiated a breast cancer screening program. On July1, 2013, all 10,000 women residing in the town were screened. Of these, 500 were diagnosed with breastcancer (assume a perfect screening test that makes no errors). Five years later, screening was done again inthe same population (assume no woman left the town or moved to the town, and no one died during thisperiod), and another 100 women were found to have developed breast cancer.The 5year cumulative incidence (or incidence proportion) of breast cancer among the 9,500 women initiallyfree of breast cancer (i.e. those women who, on July 1, 2013, were at risk of developing breast cancer in
9/8/2018Yiyang Yue's Quiz History: Quiz 1: Measures of frequency, association and effect / Cohort design6/9subsequent years) is:a. 0.0100b. 0.0105Correct!Correct!1 / 1 ptsQuestion 6A study was designed to understand the association between alcohol consumption and mortality. Participantswere males and females aged 18 years and older, living in the Boston area, and followed until death (assumethere is no other way in which participants leave the study, i.e., there is no loss to followup). Recruitment forthis study happened between January 1, 2018 and May 1, 2018. On the time axis of ‘time from start ofobservation’ (or ‘time since study recruitment’), this is an example of:
9/8/2018Yiyang Yue's Quiz History: Quiz 1: Measures of frequency, association and effect / Cohort design7/9Correct!Correct!