Chapter 7. Categorical Variables: Rates and Proportions

  1. Jennifer Peat1 and
  2. Belinda Barton2
  1. Martin Bland Statistician

Published Online: 14 JAN 2008

DOI: 10.1002/9780470755945.ch7

Medical Statistics: A Guide to Data Analysis and Critical Appraisal

Medical Statistics: A Guide to Data Analysis and Critical Appraisal

How to Cite

Peat, J. and Barton, B. (2005) Categorical Variables: Rates and Proportions, in Medical Statistics: A Guide to Data Analysis and Critical Appraisal, Blackwell Publishing Inc., Malden, Massachusetts, USA. doi: 10.1002/9780470755945.ch7

Author Information

  1. 1

    Associate Professor, Department of Paediatrics and Child Health, University of Sydney and Senior Hospital Statistician, Clinical Epidemiology Unit, Children's Hospital at Westmead, Sydney, Australia

  2. 2

    Head of Children's Hospital Education Research Institute (CHERI) and Psychologist, Neurogenetics Research Unit, The Children's Hospital at Westmead, Sydney, Australia

Publication History

  1. Published Online: 14 JAN 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9780727918123

Online ISBN: 9780470755945

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Keywords:

  • proportions;
  • surgery;
  • children;
  • confidence;
  • chi-square test

Summary

This chapter contains section titled:

  • Baseline characteristics

  • Describing categorical data

  • Chi-square tests

  • Research question

  • Confidence intervals

  • Creating a figure using SigmaPlot

  • 2×3 chi-square tables

  • Research question

  • Cells with small numbers

  • Re-coding to avoid small cell numbers

  • Presenting the results: crosstabulated information

  • Differences in proportions

  • Presenting the results: differences in percentages

  • Research question

  • Larger chi-square tables

  • Research question

  • Chi-square trend test for ordered variables

  • Research question

  • Presenting the results

  • Number needed to treat

  • If nothing goes wrong, is everything OK?

  • Paired categorical variables

  • Research question

  • Presenting the results

  • Notes for critical appraisal