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Old 05-12-2002, 04:38 AM   #1
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Post Medical language for medical guys: a question

Assuming detection of a significantly increased risk of 2-fold in these genotypes, our study can detect at about 76% power among 100 cases and 196 controls


I found the above sentence in a document I am editing. What does she mean "76% power?" The article is on cervical cancer.

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Old 05-12-2002, 05:47 AM   #2
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Quote:
Originally posted by Vorkosigan:
<strong>Assuming detection of a significantly increased risk of 2-fold in these genotypes, our study can detect at about 76% power among 100 cases and 196 controls


I found the above sentence in a document I am editing. What does she mean "76% power?" The article is on cervical cancer.

Vorkosigan</strong>
Power is a statistical term meaning the probability of rejecting the null hypothesis given that it is actually false.

In this case, the null hypothesis is probably that cervical cancer is not present. So 76% of the time, their test would be able to detect cancer when in fact there is cancer.

In mathematical terms, if the probability of not detecting a cancer when in fact there is cancer is b, then the statistical power is 1-b.

Scientiae

[ May 12, 2002: Message edited by: Scientiae ]</p>
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Old 05-12-2002, 02:02 PM   #3
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Thanks, Sci!

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Old 05-12-2002, 06:42 PM   #4
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You got it covered Scientiae. What seems left unsaid is their rate of false positives.
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