Korean J Lab Med 2009; 29(1): 1-9

Published online February 1, 2009

Copyright © Korean Society for Laboratory Medicine.

Correct Use of Repeated Measures Analysis of Variance

Eunsik Park, Ph.D.1, Meehye Cho, B.Sc.1, and Chang-Seok Ki, M.D.2

Department of Statistics1, College of Natural Sciences, Chonnam National University, Gwangju; Department of Laboratory Medicine and Genetics2, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

Correspondence to: Eunsik Park, Ph.D.
Department of Statistics, College of Natural Sciences, Chonnam National University, 300 Yongbong-ro, Buk-gu, Gwangju 500-757, Korea
Tel : +82-62-530-3448, Fax : +82-62-530-3449
E-mail :

*This work was supported by a Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MOST) (R01-2006-000-11087-0).

Received: December 2, 2008; Revised: February 6, 2009; Accepted: February 21, 2009


In biomedical research, researchers frequently use statistical procedures such as the t-test, standard analysis of variance (ANOVA), or the repeated measures ANOVA to compare means between the groups of interest. There are frequently some misuses in applying these procedures since the conditions of the experiments or statistical assumptions necessary to apply these procedures are not fully taken into consideration. In this paper, we demonstrate the correct use of repeated measures
ANOVA to prevent or minimize ethical or scientific problems due to its misuse. We also describe the appropriate use of multiple comparison tests for follow-up analysis in repeated measures ANOVA. Finally, we demonstrate the use of repeated measures ANOVA by using real data and the statistical software package SPSS (SPSS Inc., USA). (Korean J Lab Med 2008;28:1-9)

Keywords: Ethics, ANOVA, Repeated measures, Multiple comparison