I am confused by the terminology in question 8H of the final. The table posted lists a "risk reduction" and event rates from hazard ratios for the atorva and pravastatin groups. The question stem mentions a "relative risk reduction" in the PROVE IT study applying for our patient. Do you mean us to the interpret the 16% risk reduction as an absolute risk risk reduction rather than a relative risk reduction? I don't see a way to calculate this without an absolute difference measure being given.
The absolute risk difference, ARD, is given by:
ARD = R1 - R0
The relative risk difference, RRD, is give by:
RRD = (R1-R0)/R0
So, the ARD is the product of the RRD and R0:
ARD = RRD*R0
In a population with a different baseline level of risk, R0', the RRD is likely to be preserved, so
ARD' = RRD*R0'