Korean J Lab Med.  2009 Feb;29(1):1-9. 10.3343/kjlm.2009.29.1.1.

Correct Use of Repeated Measures Analysis of Variance

• Park E
• Cho M
• Ki CS

• KMID: 1781587
• DOI: http://doi.org/10.3343/kjlm.2009.29.1.1

Abstract

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).

Keyword

Ethics; ANOVA; Repeated measures; Multiple comparison

MeSH Terms

*Analysis of Variance
Chemistry, Clinical
*Models, Statistical
Multivariate Analysis
Reproducibility of Results

Reference

1.Altman DG. Statistics and ethics in medical research. VIII-Improving the quality of statistics in medical journals. Br Med J. 1981. 282:44–6.

2.Gardenier JS., Resnik DB. The misuse of statistics: concepts, tools, and a research agenda. Account Res. 2002. 9:65–74.

3.Bailar JC 3rd. Science, statistics and deception. Ann Intern Med. 1986. 104:259–60.

4.Altman DG., Bland JM. Comparing several groups using analysis of variance. Br Med J. 1996. 312:1472–3.

5.Bergh DD. Problems with repeated measures analysis: Demonstration with a study of the diversification and performance relationship. Acad Manage J. 1995. 38:1692–708.

6.LaTour SA., Miniard PW. The misuse of repeated measures analysis in marketing research. J Mark Res. 1983. 20:45–57.

7.Jung CL., Cho SE., Hong KS. Clinical significance of minor elevation of Cardiac Troponin I. Korean J Lab Med. 2008. 28:339–45. (정채림, 조성은, 홍기숙. Cardiac Troponin I 경도 증가의 임상적 의의. 대한진단검사의학회지 2008;28: 339-45.).

8.Oh SH., Ki CS. Comparison of two new plastic tubes (Sekisui INSEPACK and green cross green Vac-Tube) with BD Vacutainer tubes for 49 analytes. Korean J Lab Med. 2007. 27:69–75. (오수현및기창석. 49종의 검사에 대한 새로운 두 종류의 플라스틱 진공채혈관(Sekisui INSEPACK 및 녹십자 Green Vac-Tube)과 BD Vacutainer 진공채혈관의비교. 대한진단검사의학회지 2007;27: 69-75.).

9.Ilcol YO., Basagan-Mogol E., Cengiz M., Ulus IH. Elevation of serum cerebral injury markers correlates with serum choline decline after coronary artery bypass grafting surgery. Clin Chem Lab Med. 2006. 44:471–8.

10.Cole JWL., Grizzle JE. Applications of multivariate analysis of variance to repeated measurements. Biometrics. 1966. 22:810–28.

11.Johnson RA, Wichern DW, editors. Applied multivariate statistical analysis. 6th ed.New York: Prentice Hall;2007.

12.Huynh H., Feldt LS. Conditions under which mean square ratios in repeated measurements designs have exact F-distributions. J Am Stat Assoc. 1970. 65:1582–9.

13.Maxwell SE, Delaney HD, editors. Designing experiments and analysing data: A model comparison perspective. Belmont: Wadsworth;1990.

14.Atkinson G. Analysis of repeated measurements in physical therapy research. Phys Ther Sport. 2001. 2:194–208.

15.Greenhouse SW., Geisser S. On methods in the analysis of profile data. Psychometrika. 1959. 24:95–112.

16.Huynh H., Feldt LS. Estimation of the box correction for degrees of freedom from sample data in the randomized block and split-plot designs. J Educ Statist. 1976. 1:69–82.

17.Strasak AM., Zaman Q., Pfeiffer KP., Gobel G., Ulmer H. Statistical errors in medical research-a review of common pitfalls. Swiss Med Wkly. 2007. 137:44–9.

18.Toothacker LE, editor. Multiple comparisons procedures: Quantitative applications in the social sciences series No. 89. Thousand Oaks: Sage Publications;1993.

19.Wright SP. Adjusted p-values for simultaneous inference. Biometrics. 1992. 48:1005–13.

20.Boik RJ. A priori tests in repeated measures designs: effects of non-sphericity. Psychometrika. 1981. 46:241–55.

21.Mitzel HC., Games PA. Circularity and multiple comparisons in repeated measures designs. Br J Math Stat Psychol. 1981. 34:253–9.

22.Maxwell SE. Pairwise multiple comparisons in repeated measures designs. J Educ Statist. 1980. 5:269–87.

23.Keselman HJ., Keselman JC. Repeated measures multiple comparison procedures: effects of violating multisample sphericity in unbalanced designs. J Educ Statist. 1988. 13:215–26.

24.Atkinson G. Analysis of repeated measurements in physical therapy research: multiple comparisons amongst level means and multifactorial designs. Phys Ther Sport. 2002. 3:191–203.