Choosing and changing the analysis scale in non-inferiority trials with a binary outcome.

ABSTRACT:

Background

The size of the margin strongly influences the required sample size in non-inferiority and equivalence trials. What is sometimes ignored, however, is that for trials with binary outcomes, the scale of the margin - risk difference, risk ratio or odds ratio - also has a large impact on power and thus on sample size requirement. When considering several scales at the design stage of a trial, these sample size consequences should be taken into account. Sometimes, changing the scale may be needed at a later stage of a trial, for example, when the event proportion in the control arm turns out different from expected. Also after completion of a trial, a switch to another scale is sometimes made, for example, when using a regression model in a secondary analysis or when combinin

SUBMITTER: Li Z 

PROVIDER: S-EPMC8847766 | biostudies-literature | 2022 Feb

REPOSITORIES: biostudies-literature