Adjusting O'Brien's test to control type I error for the generalized nonparametric Behrens-Fisher problem.


Journal Article

O'Brien (1984, Biometrics 40, 1079-1087) introduced a simple nonparametric test procedure for testing whether multiple outcomes in one treatment group have consistently larger values than outcomes in the other treatment group. We first explore the theoretical properties of O'Brien's test. We then extend it to the general nonparametric Behrens-Fisher hypothesis problem when no assumption is made regarding the shape of the distributions. We provide conditions when O'Brien's test controls its error probability asymptotically and when it fails. We also provide adjusted tests when the conditions do not hold. Throughout this article, we do not assume that all outcomes are continuous. Simulations are performed to compare the adjusted tests to O'Brien's test. The difference is also illustrated using data from a Parkinson's disease clinical trial.

Full Text

Cited Authors

  • Huang, P; Tilley, BC; Woolson, RF; Lipsitz, S

Published Date

  • June 2005

Published In

Volume / Issue

  • 61 / 2

Start / End Page

  • 532 - 539

PubMed ID

  • 16011701

Pubmed Central ID

  • 16011701

Electronic International Standard Serial Number (EISSN)

  • 1541-0420

International Standard Serial Number (ISSN)

  • 0006-341X

Digital Object Identifier (DOI)

  • 10.1111/j.1541-0420.2005.00322.x


  • eng