When Is Stratification Detrimental to a Clinical Trial Design? Part I. Gretchen Marcucci, M.S . Biostatistician, Rho, Inc . and Katherine L. Monti, Ph.D. Rho, Inc. and University of North Carolina. Outline. Introduction Motivation for the literature search Why stratify? Advantages
Gretchen Marcucci, M.S.
Biostatistician, Rho, Inc.
Katherine L. Monti, Ph.D.
Rho, Inc. and University of North Carolina
Perfect balance with 4 treatments.
How many strata depends on:
If stratification is not done at randomization, covariate analysis can be performed.
Consider stratifying only if:
Authors are still (1999) concluding that “Stratification is … harmless always, useful frequently, and important rarely”. (Kernan et. al., 1999)
The preconception that stratification would improve the balance and could not hurt should be reconsidered.