Statistics review 4: sample size calculations
- PMID: 12225610
- PMCID: PMC137461
- DOI: 10.1186/cc1521
Statistics review 4: sample size calculations
Abstract
The present review introduces the notion of statistical power and the hazard of under-powered studies. The problem of how to calculate an ideal sample size is also discussed within the context of factors that affect power, and specific methods for the calculation of sample size are presented for two common scenarios, along with extensions to the simplest case.
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