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In a comprehensive meta-analysis the 'summary RR per 120 g/day increase in red meat intake was 1.20 (95% CI 1.04–1.38)' In a review citing this information, they have written rather 'a 20% increase in risk of diabetes per 120-g/d increase in red meat intake...'

And they have repeated this pattern again wherein the meta-analysis stated that 'the summary RR per 50 g/day was 1.57 (95% CI 1.28–1.93)' and the review citing this information has written rather '...for processed red meat, a 57% increase in risk per 50-g/d increase '

How would they have converted the summary RR to an absolute risk like this? I can physically see where the number has come from, rather I am interested in the 'how' and 'why' of it, cause it just doesn't click in my head!

Thank you,

Elle
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  • Their wording is poor, by 57% increase they do not mean 57 percentage points as you understand. – mdewey Apr 17 '18 at 12:31

1 Answers1

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How would they have converted the summary RR to an absolute risk like this?

A risk ratio of 1.57 means that the one risk is relatively 1.57 times the other risk. The relative difference in risk is 57%.

Example: Say the absolute risk for the one group is 3%, and the risk for the other group is 4.71%. Then the absolute difference is 1.71%, which is 57% of 3%.

Sextus Empiricus
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