Course Notes - Department of Mathematics and Statistics

• Given the s.e.(OR) = 0.751. This has a 95% confidence intervalfor the OR of (1.45,27.45). Suggesting that we have significantresult• The interpretation of this result is that the odds of having higherlevels of Dieldrin in your breastmilk are 630% higher if you livein a house that has been treated in the last 3 years.• Alternatively we can fit a logistic regression model.• Y = Dieldrin > 0.009ppm ; 1 = Yes 0 = No• x 1 = House treated in the last 3 years; 1 = Yes 0 = No.• Regression model is;Ln( p1−p ) = β 0 + β 1 x 1 + ɛ• Where p is the probability that a person has elevated Dieldrinlevels.• To run this in Rexcel we select:Statistics > Fit models > Generalized linear model• We need to make sure the Family is set to binomial and the Linkfunction is logitLogistic Regression output256