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Comparison of model- and design-based approaches to detect the treatment effect and covariate by treatment interactions in three-level models for multisite cluster-randomized trials.
- Source :
-
Behavior Research Methods . Feb2019, Vol. 51 Issue 1, p243-257. 15p. - Publication Year :
- 2019
-
Abstract
- In this study, we evaluated the estimation of three important parameters for data collected in a multisite cluster-randomized trial (MS-CRT): the treatment effect, and the treatment by covariate interactions at Levels 1 and 2. The Level 1 and Level 2 interaction parameters are the coefficients for the products of the treatment indicator, with the covariate centered on its Level 2 expected value and with the Level 2 expected value centered on its Level 3 expected value, respectively. A comparison of a model-based approach to design-based approaches was performed using simulation studies. The results showed that both approaches produced similar treatment effect estimates and interaction estimates at Level 1, as well as similar Type I error rates and statistical power. However, the estimate of the Level 2 interaction coefficient for the product of the treatment indicator and an arithmetic mean of the Level 1 covariate was severely biased in most conditions. Therefore, applied researchers should be cautious when using arithmetic means to form a treatment by covariate interaction at Level 2 in MS-CRT data. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 1554351X
- Volume :
- 51
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Behavior Research Methods
- Publication Type :
- Academic Journal
- Accession number :
- 135693561
- Full Text :
- https://doi.org/10.3758/s13428-018-1080-1