What is a crude rate and how is it used? How simple (or difficult) is it to determine?

What will be an ideal response?

A crude rate, also referred to as a raw rate, is a rate from the entire population under observation, and consists of a numerator that is all events from the population, and a denominator that is the entire population under observation.   As long as the events have a good definition, and the population is defined, a crude rate is simple to determine.   Because of this simplicity, a crude rate is useful for describing the distribution of a disease or an exposure in the defined population and it provides one overall rate.  However, unless another rate uses the same exact people in the denominator, at the same time, it is not appropriate to compare crude rates.