hi Yassine, There are alternatives to the mixture approach that would probably work better in your case and can be used in the context of an scm too, see e.g.:
AAPS J. 2013 Oct;15(4):1232-41. doi: 10.1208/s12248-013-9526-y. Comparison of methods for handling missing covariate data. Johansson ÅM, Karlsson MO. (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3787222) AAPS J. 2012 Sep;14(3):601-11. doi: 10.1208/s12248-012-9373-2. Epub 2012 May 31. Performance of methods for handling missing categorical covariate data in population pharmacokinetic analyses. Keizer RJ, Zandvliet AS, Beijnen JH, Schellens JH, Huitema AD. (http://www.ncbi.nlm.nih.gov/pubmed/22648902) best regards, Ron ------------------------------- Pirana Software & Consulting BV @ronpirana
