Sample size: How many patients are necessary?

P. M. Fayers*, D. Machin

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

58 Citations (Scopus)


The need for sample size calculations is briefly reviewed: Many of the arguments against small trials are already well known, and we only cursorily repeat them in passing. Problems that arise in the estimation of sample size are then discussed, with particular reference to survival studies. However, most of the issues which we discuss are equally applicable to other types of study. Finally, prognostic factor analysis designs are discussed, since this is another area in which experience shows that far too many studies are of an inadequate size and yield misleading results.

Original languageEnglish
Pages (from-to)1-9
Number of pages9
JournalBritish Journal of Cancer
Issue number1
Publication statusPublished - 1 Jan 1995


  • Number of patients
  • Power calulation
  • Randomised trials
  • Sample size
  • Study size


Dive into the research topics of 'Sample size: How many patients are necessary?'. Together they form a unique fingerprint.

Cite this