odds ratio question

[drake19]

for breast fed infants the #dead is "A" and # alive is "B"
and
for bottle fed infants the # dead is "C" and # alive is "D"
how does the researcher calculate the odds ratio of being alive if newborn was breast fed compared to bottle fed

according to answers odds ratio is A/B x C/D or (AxD) / (CxB)

can anyone explain? Thanks

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[lymphocyte]

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[derp123]

for breast fed infants the #dead is "A" and # alive is "B"
and
for bottle fed infants the # dead is "C" and # alive is "D"
how does the researcher calculate the odds ratio of being alive if newborn was breast fed compared to bottle fed

according to answers odds ratio is A/B x C/D or (AxD) / (CxB)

can anyone explain? Thanks

Hm. The odds ratio is the "ratio" of the odds of the outcome occurring given the exposure compared the odds of the outcome occurring given the absence of the exposure. So the exposure is "breast feeding", absence of the exposure is "bottle feeding" and the outcome is "alive." If we look at this as a case-control study, "alive" would be the "case" and "dead" would be the "control." This is a little counter-intuitive but if thats how the question is worded it would give us the following:

Odds of the outcome given the exposure: B/A
Odds of the outcome given the absence of the exposure: D/C

Odds Ratio: (B/A) / (D/C)

This is the odds ratio of being alive if newborn was breast fed compared to bottle fed (taking alive as the outcome). If you take death as the outcome then you would get (A/B)/(C/D).

Do you have any more information on the question? I'm a little rusty on this stuff so I could be wrong!

 

[MrWonderful]

Odds Ratio = (A/C) / (B/D), which can be re-written as (AD) /(BC)

Make sure you understand the difference b/w Cohort and Case Control studies, as far as which study is used with which calculation. High yield.

 

[mgw5065]

Odds Ratio = (A/C) / (B/D), which can be re-written as (AD) /(BC)

Make sure you understand the difference b/w Cohort and Case Control studies, as far as which study is used with which calculation. High yield.

SHOOOOOOOO

 

[lymphocyte]

for breast fed infants the #dead is "A" and # alive is "B"
and
for bottle fed infants the # dead is "C" and # alive is "D"
how does the researcher calculate the odds ratio of being alive if newborn was breast fed compared to bottle fed

according to answers odds ratio is A/B x C/D or (AxD) / (CxB)

can anyone explain? Thanks

You made a mistake in transcribing the question. A and C must be the number alive for you to calculate the odds ratio of being alive with the equation you provided.