calculating rate ratio controlling for other factors?

Question

In cohort studies how would you calculate for rate ratios controlling for other factors

Answer 1

An example in one study on smoking:

"The numerator of the rate is the number of diseased subjects and the denominator is usually the number of person-years of observation. The incidence rates for exposed and non-exposed subjects are calculated separately."
"hort and case-control studies are observational studies and are potentially subject to the effect of extraneous factors which may distort the findings of these studies. The term confounding—or confounding factor—used in this context, refers to an extraneous variable that satisfies both of two conditions."
For more from this excellent article by the Geneva Foundation see:
http://www.gfmer.ch/Books/Reproductive_health/Cohort_and_case_control_studies.html

For more information on the full subject of cohurt studies, choose the source that best meets your needs from the list of sources below.