Abstract
Current practice results in the publication of many research studies in medical and related disciplines which may be criticised on the grounds of inadequate sample size and statistical power. Small studies continue to be carried out with little more than a blind hope of showing the desired effect. Nevertheless, papers based on such work are submitted for publication, especially if the results turn out to be statistically significant. There is confusion about what makes a result suitable for publication. Often there is a preference for statistically significant results at the peer review stage. Consequently published reports of small studies tend to contain too many false positive results and to exaggerate the true effects. The use of a criterion of a posteriori power does not eliminate the bias; a priori power is the criterion of choice. This could be implemented by peer review of study protocols at the planning stage by funding bodies and journals.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Altman D. G. Statistics and ethics in medical research: III How large a sample? Br Med J. 1980 Nov 15;281(6251):1336–1338. doi: 10.1136/bmj.281.6251.1336. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Freiman J. A., Chalmers T. C., Smith H., Jr, Kuebler R. R. The importance of beta, the type II error and sample size in the design and interpretation of the randomized control trial. Survey of 71 "negative" trials. N Engl J Med. 1978 Sep 28;299(13):690–694. doi: 10.1056/NEJM197809282991304. [DOI] [PubMed] [Google Scholar]
- Gardner M. J., Altman D. G. Confidence intervals rather than P values: estimation rather than hypothesis testing. Br Med J (Clin Res Ed) 1986 Mar 15;292(6522):746–750. doi: 10.1136/bmj.292.6522.746. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gardner M. J., Machin D., Campbell M. J. Use of check lists in assessing the statistical content of medical studies. Br Med J (Clin Res Ed) 1986 Mar 22;292(6523):810–812. doi: 10.1136/bmj.292.6523.810. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schor S., Karten I. Statistical evaluation of medical journal manuscripts. JAMA. 1966 Mar 28;195(13):1123–1128. [PubMed] [Google Scholar]