Chapter 14. Sample Sizes
Published Online: 8 MAR 2002
DOI: 10.1002/0470846283.ch14
Copyright © 2000 John Wiley & Sons, Ltd
Book Title
Quality of Life: Assessment, Analysis and Interpretation
Additional Information
How to Cite
Fayers, P. M. and Machin, D. (2002) Sample Sizes, in Quality of Life: Assessment, Analysis and Interpretation, John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/0470846283.ch14
Publication History
- Published Online: 8 MAR 2002
- Published Print: 18 APR 2000
ISBN Information
Print ISBN: 9780471968610
Online ISBN: 9780470846285
- Summary
- Chapter
Keywords:
- significance tests;
- p-values;
- means-paired;
- proportions-unpaired;
- means-unpaired;
- proportions-paired;
- time-to-event data;
- equivalence studies
Summary
This chapter describes how sample sizes may be estimated for QoL studies. To obtain such sample sizes it is necessary to specify, at the planning stage of the study, the size of effect that is expected. The type of statistical tests to be used with the subsequent data needs to be stipulated, as do the significance level and power. Situations in which means, proportions, ordered categorical, and time-to-event outcomes are relevant are described. Sample size considerations are included for the difference between groups, comparison with a reference population and equivalence studies, as well as unpaired and paired situations. The consequences of comparing more than two groups or simultaneously investigating several endpoints are discussed.