Mixed effects models with censored data with application to HIV RNA levels

Biometrics. 1999 Jun;55(2):625-9. doi: 10.1111/j.0006-341x.1999.00625.x.


Mixed effects models are often used for estimating fixed effects and variance components in longitudinal studies of continuous data. When the outcome being modelled is a laboratory measurement, however, it may be subject to lower and upper detection limits (i.e., censoring). In this paper, the usual EM estimation procedure for mixed effects models is modified to account for left and/or right censoring.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Algorithms
  • Biometry*
  • HIV / isolation & purification
  • HIV Infections / virology*
  • Humans
  • Longitudinal Studies
  • Male
  • Models, Statistical*
  • RNA, Viral / analysis*


  • RNA, Viral