Variable-Domain Functional Regression for Modeling ICU Data

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


We introduce a class of scalar-on-function regression models with subject-specific functional predictor domains. The fundamental idea is to consider a bivariate functional parameter that depends both on the functional argument and on the width of the functional predictor domain. Both parametric and nonparametric models are introduced to fit the functional coefficient. The nonparametric model is theoretically and practically invariant to functional support transformation, or support registration. Methods were motivated by and applied to a study of association between daily measures of the Intensive Care Unit (ICU) sequential organ failure assessment (SOFA) score and two outcomes: in-hospital mortality, and physical impairment at hospital discharge among survivors. Methods are generally applicable to a large number of new studies that record a continuous variables over unequal domains. Supplementary materials for this article are available online.

Original languageEnglish (US)
Pages (from-to)1425-1439
Number of pages15
JournalJournal of the American Statistical Association
Issue number508
StatePublished - Oct 2 2014


  • Functional data analysis
  • Longitudinal data
  • Nonparametric statistics
  • Scalar-on-function regression
  • Variable-domain functional regression
  • Varying-coefficient model

ASJC Scopus subject areas

  • Statistics and Probability
  • Statistics, Probability and Uncertainty


Dive into the research topics of 'Variable-Domain Functional Regression for Modeling ICU Data'. Together they form a unique fingerprint.

Cite this