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Interim analysis: The alpha spending function approach
Author(s) -
Demets David L.,
Lan K. K. Gordon
Publication year - 1994
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.4780131308
Subject(s) - interim , frequentist inference , interim analysis , flexibility (engineering) , type i and type ii errors , computer science , function (biology) , econometrics , statistics , clinical trial , medicine , mathematics , bayesian probability , bayesian inference , archaeology , evolutionary biology , biology , history , pathology
Interim analysis of accumulating data in a clinical trial is now an established practice for ethical and scientific reasons. Repeatedly testing interim data can inflate false positive error rates if not handled appropriately. Group sequential methods are a commonly used frequentist approach to control this error rate. Motivated by experience of clinical trials, the alpha spending function is one way to implement group sequential boundaries that control the type I error rate while allowing flexibility in how many interim analyses are to be conducted and at what times. In this paper, we review the alpha spending function approach, and detail its applicability to a variety of commonly used statistical procedures, including survival and longitudinal methods.