2. Linear Regression
Published Online: 11 OCT 2013
Copyright © 2014 Bee Choo Tai and David Machin.
Regression Methods for Medical Research
How to Cite
Tai, B. C. and Machin, D. (2013) Linear Regression, in Regression Methods for Medical Research, John Wiley & Sons Ltd, Oxford. doi: 10.1002/9781118721957.ch2
- Published Online: 11 OCT 2013
- Published Print: 29 NOV 2013
Print ISBN: 9781444331448
Online ISBN: 9781118721957
- discrete covariates;
- linear regression models;
- study design;
- unordered categorical covariate
This chapter describes the different types of covariates that may arise when using linear regression models and how preliminary screening of these using graphical techniques may be useful. It describes how an unordered categorical covariate of more than two levels is included in a model by the technique of creating dummy variables. The authors include discussion of covariates of ordered categorical and numerically discrete forms. Several methods are described for verifying whether or not a chosen linear model, once fitted to the data, is appropriate for the study concerned. The authors caution against the use of ‘in-house’ statistical software and recommend that as simple a model structure as possible is used for summarizing the data collected. Aspects concerned with the choice of study design and subsequent reporting are also included.