Using e-mail recruitment and an online questionnaire to establish effect size: A worked example
<p>Abstract</p> <p>Background</p> <p>Sample size calculations require effect size estimations. Sometimes, effect size estimations and standard deviation may not be readily available, particularly if efficacy is unknown because the intervention is new or developing, or t...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2011-06-01
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| Series: | BMC Medical Research Methodology |
| Online Access: | http://www.biomedcentral.com/1471-2288/11/89 |