title: Sample size and power analysis for endometrial safety studies.
abstract: Endometrial safety studies are required for the approval of progestin components. The Committee for Proprietary Medicinal Products requirement is the actual percentage below 2% and the upper limit of the one-sided exact 95% confidence interval not more than 2% above the point estimate. The more recent U.S. Food and Drug Administration requirement is the actual percentage < or = 1% and the upper limit of the one-sided exact 95% confidence interval < or =4%. I studied the sample size and power needed to satisfy both requirements based on the exact confidence intervals for the binomial parameter and the Poisson parameter. I discovered that a larger sample size does not always lead to a higher power. I presented a best sample size that satisfies both requirements and recommended that the patient enrollment should be closely monitored during the study.
authors.affiliation: Novartis Pharmaceuticals, One Health Plaza, East Hanover, NJ 07936, USA. guoqin.su@novartis.com
authors.forename: Guoqin
authors.initials: G
authors.lastname: Su
mesh_terms: D000368:Aged; D000465:Algorithms; D003627:Data Interpretation, Statistical; D016889:Endometrial Neoplasms / Q000139:chemically induced* / Q000453:epidemiology*; D015914:Estrogen Replacement Therapy / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008875:Middle Aged; D016012:Poisson Distribution; D018570:Risk Assessment; D018401:Sample Size