Simple fitting of subject-specific curves for longitudinal data. Academic Article

abstract

• We present a simple semiparametric model for fitting subject-specific curves for longitudinal data. Individual curves are modelled as penalized splines with random coefficients. This model has a mixed model representation, and it is easily implemented in standard statistical software. We conduct an analysis of the long-term effect of radiation therapy on the height of children suffering from acute lymphoblastic leukaemia using penalized splines in the framework of semiparametric mixed effects models. The analysis revealed significant differences between therapies and showed that the growth rate of girls in the study cannot be fully explained by the group-average curve and that individual curves are necessary to reflect the individual response to treatment. We also show how to implement these models in S-PLUS and R in the appendix.

authors

• Carroll, Raymond

published proceedings

• Stat Med

author list (cited authors)

• Durbn, M., Harezlak, J., Wand, M. P., & Carroll, R. J.

citation count

• 136

complete list of authors

• Durbán, M||Harezlak, J||Wand, MP||Carroll, RJ

publication date

• April 2005

publisher

• Wiley  Publisher

published in

• Statistics in Medicine  Journal

keywords

• Biometry
• Body Height
• Child
• Child, Preschool
• Data Interpretation, Statistical
• Female
• Humans
• Linear Models
• Longitudinal Studies
• Models, Statistical
• Precursor Cell Lymphoblastic Leukemia-lymphoma
• Software

PubMed Central ID

• 15568201

Digital Object Identifier (DOI)

• 10.1002/sim.1991

start page

• 1153

end page

• 1167

volume

• 24

issue

• 8

URL

• http%3A%2F%2Fdx.doi.org%2F10.1002%2Fsim.1991