Question

The relationship between prevalence and incidence can be summed up by a mathematical formula. Write that mathematical formula here:

Using the information you have provided above, complete the following sentences with one of the choices provided in parentheses:

a. If the incidence rate for a disease is low and the disease duration is short, we would expect the disease’s prevalence to be relatively __________ (high, low).

b. If the incidence rate for a disease is high and the disease duration is __________ (long, short), we would expect the disease’s prevalence to be relatively high.

c. The duration of disease A is longer than disease B. If the incidence of diseases A and B are the same, we can expect the prevalence of disease A to be relatively __________ (higher/lower) than disease B.

Answer 1

prevalence = incidence rate x average duration of disease

mathematically,

P/(1-P) = IR X AVG. DURATION.

Here, P is population with disease, (1-P) is population without disease, IR is the incident rate and avg. duration is the avg time that havethe disease.

a, low as per the formula mentioned above if IR is low and avg duuration is also short then multiplying two low components will give low prevalence.

b. long. as two two long values multiplied will give a relatively higher value.

c. higher as the IR is the same and the time for A is longer and after multiplication as per the formula the prevalance for A will be higher