Tree-based varying coefficient regression for longitudinal ordinal responses

Bürgin, Reto; Ritschard, Gilbert

doi:10.1016/j.csda.2015.01.003

Cited by 19 publications

(10 citation statements)

References 25 publications

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“…For each site, the model showing the lowest Akaike information criterion value was selected as the best model (Burnham & Anderson, ). Statistical analyses were performed using the vcrpart package in r (Bürgin & Ritschard, ).…”

Section: Methodsmentioning

confidence: 99%

Delineating limits: Confronting predicted climatic suitability to field performance in mistletoe populations

et al. 2018

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1. Biotic stressors such as hemiparasites have a profound impact on forest functioning. However, predicting the future incidence of these stressors on forests remains challenging because climate-based distribution does not consider tree-hemiparasite interactions or the impacts of extreme climate events on stressors' performance.2. We use species distribution models (SDMs) and ecophysiological and demographic field data to assess whether climatic suitability is a proxy for the performance of the hemiparasite mistletoe (Viscum album) in two forests with contrasting climatic conditions. Two host tree species representing wet-cold (Scots pine) and drywarm (Aleppo pine) conditions were selected. We fitted SDMs based on climate variables, and measured different ecophysiological variables capturing cold-(photoinhibition) and drought tolerance (intrinsic water-use efficiency, iWUE). We also assessed demographic variables related to seed germination and establishment rates of mistletoe through a translocation experiment.3. Species distribution models showed a high climatic suitability of mistletoe in both forests. Mistletoes living in the Scots pines site presented a higher cold tolerance, while those inhabiting the Aleppo pine site showed a higher iWUE. Seedlings coming from local seeds showed a lower mortality than seedlings coming from translocated seeds. Germination and seedling establishment showed temporal mismatches when comparing local and translocated seeds. 4. Synthesis. Habitat suitability predicted by SDMs based on climate data and field performance were related in this mistletoe species. However, ecophysiological and demographic variables indicated a lower fitness of mistletoe in the drywarm site associated with drought stress. In conclusion, predicted climate suitability based on SDMs forecasts should be refined using field data on actual performance and considering plant-to-plant interactions and extreme climate events. K E Y W O R D S cold tolerance, establishment, germination, hemiparasitic plant, Species Distribution Models, Viscum album, water-use efficiency | 2219 Journal of Ecology SANGÜESA-BARREDA Et Al.

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Section: Methodsmentioning

confidence: 99%

Delineating limits: Confronting predicted climatic suitability to field performance in mistletoe populations

et al. 2018

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“…We acknowledge that our approaches to tackle missing data are crude, and more refined methods have been proposed before. 48,49 The framework of joint model of longitudinal drinking and time to dropout 10 may also be considered in future work. Finally, comparing curves has been widely discussed in the literature, 50–53 it is of interest to adopt these more rigorous inferential approaches in our method.…”

Section: Discussionmentioning

confidence: 99%

Precision medicine: Subgroup identification in longitudinal trajectories

Wei

Liu

et al. 2020

Stat Methods Med Res

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In clinical studies, the treatment effect may be heterogeneous among patients. It is of interest to identify subpopulations which benefit most from the treatment, regardless of the treatment’s overall performance. In this study, we are interested in subgroup identification in longitudinal studies when nonlinear trajectory patterns are present. Under such a situation, evaluation of the treatment effect entails comparing longitudinal trajectories while subgroup identification requires a further evaluation of differential treatment effects among subgroups induced by moderators. To this end, we propose a tree-structured subgroup identification method, termed “interaction tree for longitudinal trajectories”, which combines mixed effects models with regression splines to model the nonlinear progression patterns among repeated measures. Extensive simulation studies are conducted to evaluate its performance and an application to an alcohol addiction pharmacogenetic trial is presented.

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“…Both these models are multivariate extensions of GLMs (cf., Fahrmeir and Tutz 2001, Chapter 3). Therefore, we can adopt the definitions for the training and validation errors for GLMs (Bürgin and Ritschard 2015).…”

Section: Extension To Other Model Classesmentioning

confidence: 99%

Coefficient-Wise Tree-Based Varying Coefficient Regression with vcrpart

Bürgin¹,

Ritschard²

2017

J. Stat. Soft.

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The tree-based TVCM algorithm and its implementation in the R package vcrpart are introduced for generalized linear models. The purpose of TVCM is to learn whether and how the coefficients of a regression model vary by moderating variables. A separate partition is built for each potentially varying coefficient, allowing the user to specify coefficient-specific sets of potential moderators, and allowing the algorithm to select moderators individually by coefficient. In addition to describing the algorithm, the TVCM is evaluated using a benchmark comparison and a simulation study and the R commands are demonstrated by means of empirical applications.

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Tree-based varying coefficient regression for longitudinal ordinal responses

Cited by 19 publications

References 25 publications

Delineating limits: Confronting predicted climatic suitability to field performance in mistletoe populations

Delineating limits: Confronting predicted climatic suitability to field performance in mistletoe populations

Precision medicine: Subgroup identification in longitudinal trajectories

Coefficient-Wise Tree-Based Varying Coefficient Regression with vcrpart

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