Sage Journals: Discover world-class research

Abstract

This paper describes a variety of issues in the design and analysis of multiclinic trials, focusing in particular on the detection and interpretation of treatment-by-clinic interaction. First Fleiss, which represents the classical approach and covers such issues as pooling the data, fixed versus random effects, and the analysis of main effects in the presence of interaction, is reviewed. Next, different methods for distinguishing quantitative from qualitative interaction are reviewed, and the influence of scale transformations on the interpretation of interaction is discussed. Finally, nonparametric procedures for detecting treatment-by-center interaction are reviewed and the advantages of the Iman/Conover-type ranking procedure are described.

Keywords

Multiclinic trials Treatment-by-clinic interaction Qualitative interaction Nonparametric tests

Get full access to this article

View all access options for this article.

References

Fleiss

Analysis of data from multiclinic trials. Control Clin Trials. 1986;7:267–275.

Ciminera

Heyse

Nguyen

Tukey

Evaluation of multicentre clinical trial data using adaptations of the Mosteller-Tukey procedure. Stat Med. 1993a;12:1047–1061.

Mosteller

Tukey

Combination of results of stated precision: I. The optimistic case. Utilitas Mathe. 1982;21A: 155–178.

Mosteller

Tukey

Combination of results of stated precision: II. A more realistic case. In W. G. Cochran's Impact on Statistics. Rao

PSRS

Sedransk

, eds. New York: Wiley; 1984;223–252.

Overall

General linear model analysis of variance. In: Coordinating Clinical Trials in Psycho-pharmacology: Planning, Documentation, and Analysis. Levine

, ed. Washington, DC: US Government Printing Office; 1979.

Gail

Simon

Testing for qualitative interactions between treatment effects and patient subjects. Biometrics. 1985;41:361–372.

Ciminera

Heyse

Nguyen

Tukey

Tests for qualitative treatment-by-centre interaction using a ‘Pushback’ procedure. Stat Med. 1993b;12: 1033–1045.

Conover

Practical Nonparametric Statistics. 2nd ed. New York: John Wiley; 1980.

Hora

Conover

The F statistic in the two-way layout with rank-score transformed data. J Am Stat Assoc. 1984;79:668–673.

10.

Akritas

The rank transform method in some two-factor designs. J Am Stat Assoc. 1990;85:73–78.

Interpreting Interaction: The Classical Approach

Abstract

Keywords

Get full access to this article

References