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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/9000

Title: Application of Semiparametric Mixed Models and Simultaneous Confidence Bands in a Cardiovascular Safety Experiment with Longitudinal Data
Authors: Maringwa, John
Geys, Helena
Shkedy, Ziv
Faes, Christel
Molenberghs, Geert
Aerts, Marc
Van Ammel, Karel
Teisman, Ard
Bijnens, Luc
Issue Date: 2008
Publisher: TAYLOR & FRANCIS INC
Citation: Journal of biopharmaceutical statistics (Print), 18(6). p. 1043-1062
Abstract: Several pharmacological studies involve experiments aimed at testing for a difference between experimental groups wherein the data are longitudinal in nature, frequently with long sequences per subject. Oftentimes, treatment effect, if present, is not constant over time. In such situations, imposing a parametric mean structure can be too complicated and/or restrictive. A more flexible approach is to model the mean using a semiparametric smooth function, estimated using, for example, penalized smoothing splines. We formulate a series of models exhibiting how the group-specific mean profiles could possibly differ. Once an appropriate model is chosen, interest lies in identifying specific time points where the groups differ. For this purpose, we propose the use of simultaneous confidence bands around the fitted models wherein the bands take into account within and between-subject variability, as well as variability arising from smoothing.
Notes: [Maringwa, John T.; Geys, Helena; Shkedy, Ziv; Faes, Christel; Molenberghs, Geert; Aerts, Marc] Univ Hasselt, Ctr Stat, B-3590 Diepenbeek, Belgium. [Geys, Helena; Ammel, Karel Van; Teisman, Ard; Bijnens, Luc] Johnson & Johnson Pharmaceut Res & Dev, Beerse, Belgium.
URI: http://hdl.handle.net/1942/9000
DOI: 10.1080/10543400802368881
ISI #: 000260764800001
ISSN: 1054-3406
Category: A1
Type: Journal Contribution
Validation: ecoom, 2009
Appears in Collections: Research publications

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