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Effects on overviews of early stopping rules for clinical trials
Author(s) -
Green Stephanie J.,
Fleming Thomas R.,
Emerson Scott
Publication year - 1987
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/sim.4780060329
Subject(s) - clinical trial , early stopping , sample size determination , medicine , statistics , computer science , mathematics , artificial intelligence , artificial neural network
Use of inappropriate stopping rules for clinical trials results in an excess of false positive conclusions when no true survival differences exist. Overviews of such trials, however, consist mainly of trials which were not stopped early, plus a few of reduced sample size which were. Simulations confirm that the level of such an overview is minimally elevated. Additional follow‐up for survival further corrects the level. In fact, for individual trials conducted according to inappropriate rules, late tests have nearly correct level. On the other hand, publication bias (differential reporting of positive results) can substantially increase the level of an overview if only published studies are included.