In the early 1990s, 7,983 elderly Dutch men and women were included in a prospec
ID: 2936035 • Letter: I
Question
In the early 1990s, 7,983 elderly Dutch men and women were included in a prospective cohort study (follow-up is involved). A number of participants were lost to follow-up during the course of the study. The investigators computed how many person-years each participant had contributed to the study until January 2000. The total was 52,137 person-years. During follow-up, 2,294 of the participants died, and of these, 577 were due to coronary heart disease.
What is the coronary heart disease-specific mortality rate/density?
8.1 per 1,000 person-years
11.1 per 1,000
25%
60 per 1000 person-years
11.1 per 1,000 person-years
A.8.1 per 1,000 person-years
B.11.1 per 1,000
C.25%
D.60 per 1000 person-years
E.11.1 per 1,000 person-years
Explanation / Answer
Coronary heart disease specific mortality rate/density = number of deaths due to coronary disease/total person years contributed by the subjects of the study
= 577/52137
= 0.0111
= 11.1 per 1000 person years (option E)