saparil
Forum Newbie
Topics: 7
Posts: 9
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a study is done to determ. if raloxifene will decrease the insidence of vertebral fracture in post menopausal women.
raloxifen placebo
N of women in sudy group 2557 2576
N of vertebral fractures 138 260
(5.4% ) ( 10.1%)
how many women nee to be treated to prevent 1 vert 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
i dont have any idea// what to do// help me please
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| drat
Forum Newbie
Topics: 0
Posts: 1
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No. needed to treat = 1/ absolute risk reduction
absolute risk reduction= event rate with placebo - event rate with treatment
filling in the values:
event rate with placebo= 260/2576
event rate with treatment= 138/2557
so absolute risk reduction = (260/2576) - (138/2557)
= 0.1 - 0.05
= 0.05
now no. needed to treat = 1/ absolute risk reduction
=1/0.05
= 20
so the answer is probably (d), i.e., 21
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