Question

The incidence of a disease is 4 per 1000 of population with a duration of 2 years. Calculate the prevalence.

• A. 8/1000
• B. 4/1000
• C. 2/1000
• D. 6/1000

Hint:

Prevalence equals incidence multiplied by duration.

Answer 1

The Correct Option is A

Step 1: For a disease in steady state, prevalence is approximately the product of the incidence rate and the average duration of the disease: \[P \approx I \times D\] Step 2: Here the incidence is \(4/1000\) and the duration is \(2\) years. Step 3: Substituting: \[P = \frac{4}{1000} \times 2 = \frac{8}{1000}\] Step 4: So the prevalence is 8 per 1000 (option a). The other choices ignore the multiplication by duration (4/1000), halve it (2/1000), or use a wrong factor (6/1000), so they are incorrect.