%0 Journal Article %1 Freedman2008 %A Freedman, Laurence S %D 2008 %J Clinical trials (London, England) %K BayesTheorem ClinicalTrialsasTopic DecisionSupportTechniques Humans Models ReproducibilityofResults Statistical %N 6 %P 635-40 %R 10.1177/1740774508098590 %T An analysis of the controversy over classical one-sided tests. %U http://www.ncbi.nlm.nih.gov/pubmed/19029216 %V 5 %X BACKGROUND: When applying classical tests of the null hypothesis in clinical trials, there has been considerable controversy over the choice between a one-sided versus a two-sided test. The choice between a one-sided and two-sided test still impacts on sample size calculations, assessment of study results by regulatory authorities, and publication of study results in academic journals. PURPOSE: To analyze the main elements in the controversy, and examine the procedures from both a Bayesian and classical viewpoint. METHODS AND RESULTS: Using a Bayesian decision framework, it is shown that there is no reason to double the p-value when moving from a one-sided to a two-sided test. Within the classical framework, it is shown that the doubling of the p-value results from a discontinuity due to testing a point null hypothesis. A three-decision rule, credited to Neyman or Wald, is presented that does not require the doubling of the p-value, and is consistent with a Bayesian approach. CONCLUSIONS: For most comparative clinical trials the three-decision rule is appropriate, and its use would abolish the controversy over one-sided tests. %@ 1740-7745

@article{Freedman2008, abstract = {BACKGROUND: When applying classical tests of the null hypothesis in clinical trials, there has been considerable controversy over the choice between a one-sided versus a two-sided test. The choice between a one-sided and two-sided test still impacts on sample size calculations, assessment of study results by regulatory authorities, and publication of study results in academic journals. PURPOSE: To analyze the main elements in the controversy, and examine the procedures from both a Bayesian and classical viewpoint. METHODS AND RESULTS: Using a Bayesian decision framework, it is shown that there is no reason to double the p-value when moving from a one-sided to a two-sided test. Within the classical framework, it is shown that the doubling of the p-value results from a discontinuity due to testing a point null hypothesis. A three-decision rule, credited to Neyman or Wald, is presented that does not require the doubling of the p-value, and is consistent with a Bayesian approach. CONCLUSIONS: For most comparative clinical trials the three-decision rule is appropriate, and its use would abolish the controversy over one-sided tests.}, added-at = {2023-02-03T11:44:35.000+0100}, author = {Freedman, Laurence S}, biburl = {https://www.bibsonomy.org/bibtex/24be9df63f045f0f6b610af5aa997a9c4/jepcastel}, city = {Gertner Institute for Epidemiology and Health Policy Research, Tel Hashomer 52161, Israel. lsf@actcom.co.il}, doi = {10.1177/1740774508098590}, interhash = {eccf0a68e38c41e181b92cdda9670ee1}, intrahash = {4be9df63f045f0f6b610af5aa997a9c4}, isbn = {1740-7745}, issn = {1740-7745}, journal = {Clinical trials (London, England)}, keywords = {BayesTheorem ClinicalTrialsasTopic DecisionSupportTechniques Humans Models ReproducibilityofResults Statistical}, month = {1}, note = {5060<m:linebreak></m:linebreak>JID: 101197451; RF: 33; ppublish;}, number = 6, pages = {635-40}, pmid = {19029216}, timestamp = {2023-02-03T11:44:35.000+0100}, title = {An analysis of the controversy over classical one-sided tests.}, url = {http://www.ncbi.nlm.nih.gov/pubmed/19029216}, volume = 5, year = 2008 }