Proposals for sample size calculation programs.
Methods Inf Med
; 46(6): 655-61, 2007.
Article
em En
| MEDLINE
| ID: mdl-18066415
ABSTRACT
OBJECTIVES:
Numerous sample size calculation programs are available nowadays. They include both commercial products as well as public domain and open source applications. We propose modifications for these programs in order to even better support statistical consultation during the planning stage of a two-armed clinical trial.METHODS:
Directional two-sided tests are commonly used for two-armed clinical trials. This may lead to a non-negligible Type III error risk in a severely underpowered study. In the case of a reasonably sized study the question for the so-called auxiliary alternative may evolve.RESULTS:
We propose that sample size calculation programs should be able to compute i) Type III errors and the so-called q-values, ii) minimum sample sizes required to keep the q-values below pre-specified levels, and iii) detectable effect sizes of the so-called auxiliary alternatives.CONCLUSIONS:
Proposals i and ii are intended to help prevent irresponsibly underpowered clinical trials, whereas the proposal iii is meant as additional assistance for the planning of reasonably sized clinical trials.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Software
/
Ensaios Clínicos como Assunto
/
Interpretação Estatística de Dados
/
Tamanho da Amostra
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Methods Inf Med
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Áustria