Logistic Regression: A Self-learning Text, Third Edition (Statistics in the Health Sciences)

Formulation affects computer output  SAS: consistent with first  SPSS and Stata: consistent with alternative formulation Advan ...

Requirement: Collapsed ORs should be “close” E¼ 0 E¼ 1 D¼ 0 45 30 D¼ 1 40 15 D¼ (^25060) The 32 table of the data is presented ...

E¼ 0 E¼ 1 E¼ 0 E¼ 1 D¼ 0 þ (^1) 85 45 D¼ (^0) 45 30 D¼ 25060 D¼ 1 þ 29075 ORd¼ 2 : 27 ORd¼ 1 : 25 Statistical test of assumption ...

OR¼ PðDgjX 1 ¼ 1 Þ=PðD<gjX 1 ¼ 1 Þ PðDgjX 1 ¼ 0 Þ=PðD<gjX 1 ¼ 0 Þ ¼ expagþb 1 ð 1 Þ  expagþb 1 ð 0 Þ ¼expðagþb^1 Þ e ...

Interpretation of intercepts(ag) ag¼log odds ofDgwhere all independent variables equal zero; g¼ 1 ; 2 ; 3 ;...;G 1 ag>agþ 1 ...

Illustration 01 a 1 = log odds D ³ 1 a 2 = log odds D ³ 2 a 4 = log odds D ³ 4 a 3 = log odds D ³ 3 234 01234 01234 01234 As the ...

IV. Extending the Ordinal Model PðDgjXÞ¼ 1 1 þexp½ðagþ~ k i¼ 1 biXiފ ; where g¼1, 2, 3,...,G 1 Note:P(D0|X)¼ 1 odds¼ PðDgj ...

The odds that the tumor grade is in a category greater than or equal to category 2 (i.e., poorly differentiated) vs. in categori ...

V. Likelihood Function for Ordinal Model odds¼ P 1 P so solving forP, P¼ odds oddsþ 1 ¼ 1 1 þ odds^1  The estimated odds rati ...

P(D¼g)¼[P(Dg)] [P(Dgþ1) ] Forg¼ 2 P(D¼2)¼P(D2)P(D3) Use relationship to obtain proba- bility that individual is in given o ...

Three separate logistic regressions Three sets of parameters a 1 vs:< 1 ; b 1 vs:< 1 a 2 vs:< 2 ; b 2 vs:< 2 a ...

If assumption not met, may  Use polytomous logistic model  Use different ordinal model  Use separate logistic models Chapter ...

Detailed Outline I. Overview(page 466) A. Focus: modeling outcomes with more than two levels. B. Ordinal outcome variables. II. ...

F. The Wald test is analogous to standard logistic regression. IV. Extending the ordinal model(pages 476–478) A. The general for ...

D. To check if the proportional odds assumption is met: i. Evaluate whether the crude odds ratios are “close”. ii. Evaluate whet ...

Practice Exercises Suppose we are interested in assessing the association between tuberculosis and degree of viral suppression i ...

State the form of the ordinal model in terms of vari- ables and unknown parameters. For the above model, state the fitted model ...

Test True or False (Circle T or F) T F 1. The disease categories absent, mild, moderate, and severe can be ordinal. T F 2. In an ...

Use the model in Question 9 to obtain the odds ratio for the mild, severe, or critical stage of disease (i.e., D  1)] comparin ...

14 Logistic Regression for Correlated Data: GEE n Contents Introduction 490 Abbreviated Outline 490 Objectives Presentation 492 ...