Using the presence of aortic stenosis as the response, fit a logistic regression model with smoking status as the single explanatory variable. Interpret the estimated coefficient of smoking status.
What are the estimated odds of suffering aortic stenosis for individuals who smoke relative to those who do not?
Construct a 95% confidence interval for the population odds ratio. Does this interval contain the value 1? What does this tell you?
Add the explanatory variable gender to the model that already contains smoking status. What are the estimated relative odds of aortic stenosis for smokers vs. nonsmokers, adjusting for gender?
Construct a 95% confidence interval for the population odds ratio that adjusts for gender. What do you conclude?
Do you believe that the relationship between the presence of aortic stenosis and smoking status differs for males and females? Explain.
Add the explanatory variable that combines the effect of gender and smoking status. Does this improve the model? Why or why not?