Hi: I was wondering if anyone could give me a brief synopsis (or where to
find it) of the advantages and disadvantages of presenting clinical trial
data as either percentages (events/patients) versus events per 1000 patient
years. In particular, in the UKPDS 33 trial any diabetes related endpoints
were reported as 40.9/1000 patient years in the intensive group and
46.0/1000 patient years in the conventional group. However when one
calculates the absolute percentages it comes out as 963/2729 = 35.3% in the
intensive group versus 438/1138 = 38.5% in the conventional group. Is the
difference because more than one event can occur in one patient? In
contrast, when one calculates the absolute percentage differences between
the groups for MI or deaths the absolute differences seem to be fairly
similar. Thanks in advance!
Dr James McCormack
Associate Professor
Faculty of Pharmaceutical Sciences
University of British Columbia
Vancouver, B.C.
604) 822-1710
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