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#1




Number Needed to Treat (NNT)!
A study is done to test a new treatment for heart failure. Patients received usual CHF treatment plus Drug X or usual treatment plus placebo. 10/50 patients who received the drug died, and 20/50 patients who received the placebo died.
What is the number needed to treat (NNT) for this new drug? A. 2 B. 5 C. 10 D. 15 E. 50 btw, how much high yield is this for ck ? NNT concept.... 
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mmtj (07172012) 
#2




B.
For every 50 patients that you treated, you had an improved outcome in 10 patients. So, if you just divide through by 10, then for every 5 patients that you treat, you have 1 improved outcome. That's basically the concept of NNT. As far as how highyield it is... it's a fairly simple concept, so even if there's a relatively small chance that you'll get a question on it, you should know what it is. Also, you should know the absolute risk reduction (ARR), which is the inverse of the NNT. You reduced the risk in 10 patients for every 50 patients who you treated, so your absolute risk reduction is 10/50=1/5, and your NNT = 1/ARR = 1/(1/5) = 5. 
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#3




Quote:
i also remember that NNT is inverse of incidence. now ARR is also inverse of NNT . stats !:sorry: 
#4




Not sure what you mean by that  maybe only in a specific context. Incidence and NNT can't be related to each other directly, since incidence is a measure of burden of disease, while NNT is a measure of treatment efficacy.

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tyagee (07122012) 
#5




In easy way NNT is inverse of absolute risk reduction.
No of patients with the risk factor  no of patients without the risk factor=ARR & NNT = 1/ARR!!! hope that it will help. This concept is really very imp for CK....HY!!!! 
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tyagee (07122012) 
#6




B
Would go with B.
The NNT is the inverse of the risk reduction ratio so: Risk reduction ratio is : 20/50  10/50 = 0.2 NNT= 1/0.2= 5 
#7




yes i would go with B)5

#8




ans is indeed B !
what will be NNH number needed to harm in this question ? Last edited by tyagee; 07122012 at 01:24 PM. 
#9




It is same as Number needed to treat.

#10




Quote:
First find absolute risk reduction=Incidence in control groupIncidence in drug group ie 20/5010/50=0.2 or 22% means that 22% of patients were saved from Heart faillure by using the drug X Now we already know that Number needed to treat= 100/absolute risk reduction plugging value from above 100/20=5 means that 5 patients would have to be treated to save one life so answer is B 
#11




Quote:
I'm not sure of what you meant by that, but you have 10 patients died after treatment with the drug X, and that's not improve the outcome. would you clarify for me please you have 40 people lived after drug X compared to 30 people compared to placebo, and that's an improvement, isn't it? so simple the table will be like this: drug placebo Alive 40 30 Dead 10 20 so ARR is 40/5030/50 and that equals 1/5. NNT= 5 anyone would correct me if I was wrong please, and also if you guys help extract NNH, that would be awesome. 
#12




I DON'T KNOW WHY THE TABLE IS LIKE THAT BUT I THINK IT'S UNDERSTANDABLE

#13




That would be number 3 I believe .
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#14




Quote:
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Tags 
BiostatisticsEpidemiology, Step2Questions 
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