Question

The dataset stenosis will be used--the one we used for a Mantel-Haenszel problem in Chapter 16.
a. 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.

How would you approach this using R?

Answer 1

Binary Logistic Regression: disease versus smoke

Link Function: Logit

Response Information

Variable Value Count

disease   1        105 (Event)

          0        110

          Total    215

Logistic Regression Table

                                               Odds     95% CI

Predictor       Coef   SE Coef      Z      P Ratio Lower Upper

Constant   -0.215709 0.182877 -1.18 0.238

smoke       0.386334 0.276238   1.40 0.162   1.47   0.86   2.53

Log-Likelihood = -147.986

Test that all slopes are zero: G = 1.965, DF = 1, P-Value = 0.161

* NOTE * No goodness of fit test performed.

* NOTE * The model uses all degrees of freedom.

Measures of Association:

(Between the Response Variable and Predicted Probabilities)

Pairs       Number Percent Summary Measures

Concordant    3417     29.6 Somers' D              0.09

Discordant    2322     20.1 Goodman-Kruskal Gamma 0.19

Ties          5811     50.3 Kendall's Tau-a        0.05

Total        11550    100.0