Researchers reported that in a sample of U.S. women aged 50 to 54 who underwent mammography, 14.4% were recalled for further evaluation; however, in a similar sample of women undergoing mammography in the United Kingdom, only 7.6% were recalled for further evaluation.

What are the observed risk and odds ratios for the association between living in the United States (“exposed”) vs. the United Kingdom (“unexposed”) and being recalled for further evaluation following mammography (outcome)?

RR=1.89; OR=2.05
RR=2.05; OR=1.89
RR=0.40; OR=0.30
RR=0.30; OR=0.40
RR=2.05; OR=3.0

RR= 1.89 OR= 2.05

To calculate the observed risk ratio (RR) and odds ratio (OR) for the association between living in the United States vs. the United Kingdom and being recalled for further evaluation following mammography, we need the number of women recalled for further evaluation in each group. Unfortunately, the provided information does not include these values.

The observed risk ratio (RR) is calculated by dividing the risk of the outcome in the exposed group (living in the United States) by the risk of the outcome in the unexposed group (living in the United Kingdom). The formula is:

RR = Risk exposed / Risk unexposed

The odds ratio (OR) is calculated by dividing the odds of the outcome in the exposed group by the odds of the outcome in the unexposed group. The formula is:

OR = (odds exposed) / (odds unexposed)

Since we don't have the necessary information, we cannot calculate the risk ratio (RR) and odds ratio (OR). Therefore, none of the options provided (RR=1.89; OR=2.05, RR=2.05; OR=1.89, RR=0.40; OR=0.30, RR=0.30; OR=0.40, RR=2.05; OR=3.0) can be selected as the correct answer.