Which of the following is a correct way to express the prevalence of any disease?

Correct option is C

Sol. Prevalence is calculated using the formula: Prevalence = Incidence rate × Average duration of disease. This formula is derived from epidemiological principles, where prevalence represents the total number of existing cases at a given time, and incidence measures new cases over a specific period. A disease with high incidence and long duration will have high prevalence, while a short-duration disease will have low prevalence.
Explanation of Each Option:
· Prevalence = incidence rate + average duration of disease: Incorrect; prevalence depends on multiplication, not addition.
· Prevalence = incidence rate ÷ average duration of disease: Incorrect; dividing incidence rate by duration does not give prevalence.
· Prevalence = incidence rate × average duration of disease: Correct answer; this is the standard epidemiological formula used to estimate disease burden.
· Prevalence = incidence rate / average duration of disease: Incorrect; wrong mathematical representation.