What is the difference between crude and age-adjusted rates?
The crude rate is the raw or unadjusted estimate. The age-adjusted rate is an artificial estimate that minimizes the effects of different age distributions and allows comparisons between different populations. It represents what the crude rate would have been in the study population if that population had the same age distribution as a “standard” population. A “standard” population is a population in which the age composition is known precisely, for example, as a result of a census.