Incidence and Prevalence N*

[Roxanita]

The prevalence of a disease is half as great in town A than it is in town B, but the incidence of the disease is no different in town A than it is in town B. Which of the following best explains these findings?

A) The case fatality rate is twice as high in town A.

B) The duration of the disease is twice as long in town B.

C) The number of new cases in town A is twice as many as those in town B.

D) People in town A use medical care facilities half as often as those in town B.

E) The proportion of asymptomatic cases is twice as much in town B than in town A

[Asclepius1]

My guess is B.

[BlakeH]

Agree with B

[Roxanita]

The prevalence of a disease is half as great in town A than it is in town B, but the incidence of the disease is no different in town A than it is in town B. Which of the following best explains these findings?

Let's analyze ...

First of all, let's put this useful formula that relates Incidence, Prevalence and Duration.

P = I x D

I know we can't use this formula like real math but in terms to see the relation it can help us...

..................P= I x D

Town A->...P= I x D(A) =>..... D(A)=P/I

Town B->...2P= I x D(B) => .....D(B)=2P/I...=> D(B)=2D(A)

From this simple relation we could see that the Duration in Town B is twice as long than the duration of the disease in town A. choice B)

Please correct me if I am wrong

[Roxanita]

mistake.

[nlamichhane]

D is the answer as incidence is rate and prevalence is a pool. if medical facilities are good, the pool will be less. (Kaplan notes)[/u][/quote]