0
$\begingroup$

Why do we measure incidence, if we can measure the prevalence of a disease for two successive years and then subtract the latter year's figure from the former years number and find out the incidence?

What is the reason we measure incidence specifically?

$\endgroup$
2
$\begingroup$

Short version: Some people will have gotten sick and then recovered, and some people will have gotten sick and then died. These people are captured in the incidence data, but don't lead to any change in prevalence.

$\endgroup$
0
$\begingroup$

Time doesn't just add new cases to a population.

If there were no deaths, the difference in prevalence would measure incidence. Some people die, or are otherwise lost to the population. These people are lost to the incident population.

The death rate for people with a disease often exceeds the death rate of everyone else, which makes calculation of incidence from change in prevalence more difficult.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.