Current sample size conventions: Flaws, harms, and alternatives
<p>Abstract</p> <p>Background</p> <p>The belief remains widespread that medical research studies must have statistical power of at least 80% in order to be scientifically sound, and peer reviewers often question whether power is high enough.</p> <p>Discussio...
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| Format: | Article |
| Language: | English |
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BMC
2010-03-01
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| Series: | BMC Medicine |
| Online Access: | http://www.biomedcentral.com/1741-7015/8/17 |
| _version_ | 1819026618941702144 |
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| author | Bacchetti Peter |
| author_facet | Bacchetti Peter |
| author_sort | Bacchetti Peter |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>The belief remains widespread that medical research studies must have statistical power of at least 80% in order to be scientifically sound, and peer reviewers often question whether power is high enough.</p> <p>Discussion</p> <p>This requirement and the methods for meeting it have severe flaws. Notably, the true nature of how sample size influences a study's projected scientific or practical value precludes any meaningful blanket designation of <80% power as "inadequate". In addition, standard calculations are inherently unreliable, and focusing only on power neglects a completed study's most important results: estimates and confidence intervals. Current conventions harm the research process in many ways: promoting misinterpretation of completed studies, eroding scientific integrity, giving reviewers arbitrary power, inhibiting innovation, perverting ethical standards, wasting effort, and wasting money. Medical research would benefit from alternative approaches, including established <it>value of information </it>methods, simple choices based on cost or feasibility that have recently been justified, sensitivity analyses that examine a meaningful array of possible findings, and following previous analogous studies. To promote more rational approaches, research training should cover the issues presented here, peer reviewers should be extremely careful before raising issues of "inadequate" sample size, and reports of completed studies should not discuss power.</p> <p>Summary</p> <p>Common conventions and expectations concerning sample size are deeply flawed, cause serious harm to the research process, and should be replaced by more rational alternatives.</p> |
| first_indexed | 2024-12-21T05:29:27Z |
| format | Article |
| id | doaj.art-3dc030e3cedd4b3ba8cd99e8d7f33ce6 |
| institution | Directory Open Access Journal |
| issn | 1741-7015 |
| language | English |
| last_indexed | 2024-12-21T05:29:27Z |
| publishDate | 2010-03-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Medicine |
| spelling | doaj.art-3dc030e3cedd4b3ba8cd99e8d7f33ce62022-12-21T19:14:34ZengBMCBMC Medicine1741-70152010-03-01811710.1186/1741-7015-8-17Current sample size conventions: Flaws, harms, and alternativesBacchetti Peter<p>Abstract</p> <p>Background</p> <p>The belief remains widespread that medical research studies must have statistical power of at least 80% in order to be scientifically sound, and peer reviewers often question whether power is high enough.</p> <p>Discussion</p> <p>This requirement and the methods for meeting it have severe flaws. Notably, the true nature of how sample size influences a study's projected scientific or practical value precludes any meaningful blanket designation of <80% power as "inadequate". In addition, standard calculations are inherently unreliable, and focusing only on power neglects a completed study's most important results: estimates and confidence intervals. Current conventions harm the research process in many ways: promoting misinterpretation of completed studies, eroding scientific integrity, giving reviewers arbitrary power, inhibiting innovation, perverting ethical standards, wasting effort, and wasting money. Medical research would benefit from alternative approaches, including established <it>value of information </it>methods, simple choices based on cost or feasibility that have recently been justified, sensitivity analyses that examine a meaningful array of possible findings, and following previous analogous studies. To promote more rational approaches, research training should cover the issues presented here, peer reviewers should be extremely careful before raising issues of "inadequate" sample size, and reports of completed studies should not discuss power.</p> <p>Summary</p> <p>Common conventions and expectations concerning sample size are deeply flawed, cause serious harm to the research process, and should be replaced by more rational alternatives.</p>http://www.biomedcentral.com/1741-7015/8/17 |
| spellingShingle | Bacchetti Peter Current sample size conventions: Flaws, harms, and alternatives BMC Medicine |
| title | Current sample size conventions: Flaws, harms, and alternatives |
| title_full | Current sample size conventions: Flaws, harms, and alternatives |
| title_fullStr | Current sample size conventions: Flaws, harms, and alternatives |
| title_full_unstemmed | Current sample size conventions: Flaws, harms, and alternatives |
| title_short | Current sample size conventions: Flaws, harms, and alternatives |
| title_sort | current sample size conventions flaws harms and alternatives |
| url | http://www.biomedcentral.com/1741-7015/8/17 |
| work_keys_str_mv | AT bacchettipeter currentsamplesizeconventionsflawsharmsandalternatives |