1 PH 240A: Chapter 14 Nicholas P. Jewell University of California Berkeley November 15, 2005
2 Logistic Regression: Assessment of Confounding
3 Consider two risk factors for CHD incidence (eg. serum cholesterol, X 1, and body weight, X 2 ) Two models:
4 Coding for WCGS Variables
5 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (1)a < (2)abab < (3)ab1b2b3b4ab1b2b3b < < (4)abab < (5)abab < (6)abab <
6 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (7)abc1c2c3c4abc1c2c3c < < (8)abcabc < (9)abcabc < (10)abcabc <
7 Logistic Regression: Introducing Interaction
8 Coding for Pancreatic Cancer Example
9 Pancreatic Cancer: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (1)a (2)abab < (3)ab1b2b3ab1b2b < (4)abab
10 Pancreatic Cancer: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (5)abcabc < (6)abcdabcd
11 Pancreatic Cancer: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (7)ab1b2b3cab1b2b3c < (8)ab1b2b3cd1d2d3ab1b2b3cd1d2d
12 Pancreatic Cancer: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (9)abcabc (10)abcdabcd
13 Pancreatic Cancer: Fitted Logistic Regression Models
14 Coding for WCGS Variables
15 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (7)abc1c2c3c4abc1c2c3c < < (8)abcabc < (9)abcabc < (10)abcabc <
16 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (11)abc1c2c3c4d1d2d3d4abc1c2c3c4d1d2d3d <
17 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (12)abc1c2c3c4dabc1c2c3c4d < (13)abcdabcd <
18 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (14)abcdabcd < (15)abcdabcd < collinearity
19 CHD Incidence Versus Body Weight
20 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (5)abab < (6)abab < Background: quadratic models & collinearity
21 WCGS: Fitted Logistic Regression Models (#) ModelParam.EstimateSDORp-valueMax. log lik. (16)abcabc (17)abcabc < (18)abab < (19)abcabc < quadratic models & collinearity