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A METHOD FOR DETERMINING THE SIZE OF INTERNAL PILOT STUDIES
Author(s) -
SANDVIK LEIV,
ERIKSSEN JAN,
MOWINCKEL PETTER,
RØDLAND EINAR ANDREAS
Publication year - 1996
Publication title -
statistics in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.996
H-Index - 183
eISSN - 1097-0258
pISSN - 0277-6715
DOI - 10.1002/(sici)1097-0258(19960730)15:14<1587::aid-sim279>3.0.co;2-f
Subject(s) - computer science , statistics , econometrics , mathematics
The assessment of sample size in clinical trials comparing population means requires a variance estimate of the main efficacy variable. When this variance estimate has a low precision, it may be appropriate to use the data from the first patients entered in the trial (‘internal pilot study’) to estimate the sample size. We suggest a method for determining the size of internal pilot studies, which aims at ensuring that this size is as large as possible, but not larger than ‘the optimal size’ of the planned study. Advantages and limitations of the method are discussed.