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Parametric Quantile Models
Quantile regression models conditional quantiles of outcome variables of interest given covariates. Its regression coefficients depend on the order of the quantile being estimated. For example, the coefficients for the median are generally different from those of the 10th centile. We have developed parametric quantile models. These are statistically efficient and may expand the potential of statistical modeling. Goodness-of-fit measures and testing procedures are available.
Papers
Frumento P, Bottai M. Parametric modeling of quantile regression coefficient functions. Biometrics. 72: 74-84, 2016.

Frumento P, Bottai M. Parametric modeling of quantile regression coefficient functions with censored and truncated data. Biometrics. 73: 1179-1188, 2017

Bottai M, Orsini N. qmodel: a command for fitting parametric quantile models. The Stata Journal, 19(2): 261-293, 2019

Sottile G, Frumento P, Chiodi M, Bottai M. A penalized approach to covariate selection through quantile regression coefficient models. Statistical Modelling. 2019

Bottai M, Cilluffo G. Nonlinear parametric quantile models. Statistical Methods in Medical Research. 2020

Frumento P, Bottai M, Fernández-Val I. Parametric modeling of quantile regression coefficient functions with longitudinal data. Journal of the American Statistical Association, 2021 (to appear)


Software
R package: "qrcm"
R package: "ctqr"

Download with the following Stata commands:

net from http://www.imm.ki.se/biostatistics/stata
net install qmodel, replace

Presentations
September 1, 2017
The new qcm command for nonlinear quantile coefficient models
2017 Nordic and Baltic Stata Users Group Meeting, Stockholm, Sweden

July 15, 2016
Parametric modeling of quantile regression coefficient functions with censored and truncated data
Workshop on Recent Advances in Quantile and M-quantile Regression, Pisa, Italy

January 8, 2015
Parametric modeling of quantile regression coefficients
Dep. Mathematics, University of Cagliari, Italy

November 12, 2014
Parametric modeling of quantile regression coefficient functions
Gothenburg University, Gothenburg, Sweden


Unit of Biostatistics, Nobels väg 13, Karolinska Institutet, 17177 Stockholm, Sweden