Prevalence and Incidence

In epidemiology, prevalence refers to the probability of people being affected by a disease in a target population.

Conversely, incidence is the probability of new occurrences of a disease within a population during a specified time interval.

For example, in Area X, a sample population of 500 had 0 cases of a disease at the beginning of the study. But after five years, 40 new cases were reported. Similarly, in Area Y, a sample population of 700 with initially 0 disease cases reported 60 new cases after seven years.

The disease prevalence in Areas X and Y is 0.08 and 0.086, respectively, suggesting that the disease is less prevalent in Area X.

On the other hand, the annual incidence in Areas X and Y is 0.016 and 0.012, respectively, indicating that the probability of encountering new cases in Area X is higher than in Area Y.