Question

A group of researchers want to conduct a clinical trial to determine whether a new cholesterol-lowering agent is useful in preventing coronary heart disease (CHD). They identified 12,327 potential participants for the trial. Upon initial exam, 309 were found to have CHD. The remaining subjects entered the trial and were divided equally into the treatment and placebo groups. Of those in treatment group, 505 developed CHD after 5 years of follow-up, while 477 developed CHD during the same period in the placebo group. What is the incidence during the 5-year study?

Answer 1

The incidence during the 5-year study is 982.

Step-by-step explanation:

The incidence refers to the number of those who newly developed the CHD during the 5-year study period. This number includes the 505, who developed CHD after 5 years of follow-up and the 477, who developed CHD during the same period in the placebo group. The incidence does not include the 309, who were found to have CHD upon the initial examination. When this number (982) is compared with the total of 12,327 potential participants in the study, the incidence rate is obtained.