05-18-2009, 08:40 AM
a study is done to see if raloxifene will decrease the incidence of verterbral fractures in post menopausal women. the results are shown:
raloxifene placebo
no of women in study group--------------------2557----------------------25576
number of verterbral fractures-------------------138-----------------------260
5.4% 10.1%
based on these results, how many women need to be treated to prevent one vertebral fracture?
a 100/5.4=18.5
b 100/10.1=10
c 100/(10.1+5.4)=6.5
d 100/(10.1-5.4)=21
e 100/(10.1 X 5.4)=2
raloxifene placebo
no of women in study group--------------------2557----------------------25576
number of verterbral fractures-------------------138-----------------------260
5.4% 10.1%
based on these results, how many women need to be treated to prevent one vertebral fracture?
a 100/5.4=18.5
b 100/10.1=10
c 100/(10.1+5.4)=6.5
d 100/(10.1-5.4)=21
e 100/(10.1 X 5.4)=2