Confounding

Rafael A. Irizarry
October 9, 2014

Are BB more valuable than singles?

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Confounding

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Adjusting with Regression

A popular approach, although not always recommended, is to use regression models to “adjust”

Here are the regression coefficients with a BB only model

(Intercept)          BB 
   326.8242      0.7126 

Note that the estimate for BB decreases

(Intercept)          BB          HR 
   287.7227      0.3897      1.5220 

Confounding explained

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Confounding explained

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Stratified Analysis

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The average difference by major is 3.5% higher for women.