Chetwynd, Amanda G. and Diggle, Peter J. and Sousa, Ines (2005) Exploratory analysis of longitudinal trials with staggered intervention times. Biostatistics, 6 (3). pp. 479-485. ISSN 1468-4357Full text not available from this repository.
Longitudinal trials involving surgical interventions commonly have subject-specific intervention times, due to constraints on the availability of surgeons and operating theatres. Moreover, the intervention often effects a discontinuous change in the mean response. We propose a nonparametric estimator for the mean response profile of longitudinal data with staggered intervention times and a discontinuity at the times of intervention, as an exploratory tool to assist the formulation of a suitable parametric model. We use an adaptation of the standard generalized additive model algorithm for estimation, with smoothing constants chosen by a cross-validation criterion. We illustrate the method using longitudinal data from a trial to assess the effect of lung resection surgery in the treatment of emphysema patients.
|Journal or Publication Title:||Biostatistics|
|Additional Information:||RAE_import_type : Journal article RAE_uoa_type : Statistics and Operational Research|
|Uncontrolled Keywords:||Back-fitting algorithm ; Cross-validation ; Exploratory analysis ; Longitudinal trials ; Lung resection surgery ; Nonparametric estimator|
|Subjects:||Q Science > QA Mathematics|
|Departments:||Faculty of Science and Technology > Mathematics and Statistics|
Faculty of Health and Medicine > Medicine
Faculty of Science and Technology > Lancaster Environment Centre
|Deposited On:||31 Mar 2008 16:35|
|Last Modified:||26 Jul 2012 16:21|
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