Problem
A group of ten older adults are followed for one calendar year (January 1 - December 31) to see if they develop colon cancer. All individuals are disease-free at the beginning of the study. Study data are reported below.
Participant 1 Developed colon cancer on July 31
Participant 2 Did not develop colon cancer during the study
Participant 3 Did not develop colon cancer during the study
Participant 4 Moved and was lost to follow-up on August 31
Participant 5 Did not develop colon cancer during the study
Participant 6 Developed colon cancer on December 31
Participant 7 Died in a motor vehicle collision on January 31
Participant 8 Died of lung cancer on October 31
Participant 9 Did not develop colon cancer during the study
Participant 10 Did not develop colon cancer during the study
• How many cases were identified (number only)?
• Imagine a situation where a new treatment for a condition is developed, thus extending the life of individuals with that condition. Assuming that the incidence of the condition remains constant, what would happen to the disease prevalence?