Modelling growth and decline in lung function in Duchenne's muscular dystrophy with an augmented linear mixed effects model

Marc A. Scott, Robert G. Norman, Kenneth I. Berger

Research output: Contribution to journalArticle


Longitudinal modelling of lung function in Duchenne's muscular dystrophy is complicated by a mixture of both growth and decline in lung function within each subject, an unknown point of separation between these phases and significant heterogeneity between individual trajectories. Linear mixed effects models can be used, assuming a single changepoint for all cases; however, this assumption may be incorrect. The paper describes an extension of linear mixed effects modelling in which random changepoints are integrated into the model as parameters and estimated by using a stochastic EM algorithm. We find that use of this 'mixture modelling' approach improves the fit significantly.

Original languageEnglish (US)
Pages (from-to)507-521
Number of pages15
JournalJournal of the Royal Statistical Society. Series C: Applied Statistics
Issue number3
StatePublished - Jul 19 2004



  • Changepoint models
  • Duchenne's muscular dystrophy
  • Longitudinal data
  • Lung function
  • Mixed effects models
  • Mixture models

ASJC Scopus subject areas

  • Statistics and Probability
  • Statistics, Probability and Uncertainty

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