What is the expression of the new number of cases of a disease or condition in a population at a specific point in time?

What is the expression of the new number of cases of a disease or condition in a population at a specific point in time?

• A. Incidence
• B. Prevalence
• C. Morbidity
• D. Mortality

Answer: (A)

Incidence measures how often new cases of a disease appear in a population over a defined period, focusing on people who were at risk and then developed the condition. It’s the count of new occurrences divided by the at-risk population, often expressed as a rate per 1,000 or per 100,000 per year. This is different from prevalence, which reflects all existing cases (new and pre‑existing) at a specific moment or over a period. Morbidity refers to illness or disease burden in general, and mortality refers to deaths. Because the emphasis here is on new cases arising in a population, incidence is the best fit.

Incidence measures how often new cases of a disease appear in a population over a defined period, focusing on people who were at risk and then developed the condition. It’s the count of new occurrences divided by the at-risk population, often expressed as a rate per 1,000 or per 100,000 per year. This is different from prevalence, which reflects all existing cases (new and pre‑existing) at a specific moment or over a period. Morbidity refers to illness or disease burden in general, and mortality refers to deaths. Because the emphasis here is on new cases arising in a population, incidence is the best fit.