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Stratification in the design of a clinical trial


, : Stratification in the design of a clinical trial. Controlled Clinical Trials 1(4): 355-361

Stratification in the design of a clinical trial is often advanced as a method for greatly improving the precision of comparisons. It is argued here that stratification in design rarely achieves more than modest benefits in precision and that it exacts a heavy price in clumsiness and increased possibilities for error in the execution of a trial. Poststratification and covariance methods are important elements in analysis, but only limited stratification is justified in the design phase.

US$19.90

PMID: 7261626

DOI: 10.1016/0197-2456(81)90040-4


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