RE: How sparse is too sparse?

From:"Serge Guzy" GUZY@xoma.com Subject: RE:[NMusers] How sparse is too sparse? Date: Thu, June 10, 2004 5:29 pm I do not agree. (in reference to Yan Feng message, Date: Thu, June 10, 2004 3:39 pm [above]) If the sampling times are distributed in a clever fashion (usually log uniform distributed is a good sampling), then population PK has the ability to estimate all the parameters if you have enough patients. The MCPEM algorithm (algorithm optimizing the same fct as FOCE with interaction)has been tested on many models with more than 1 PK parameters with 1 sample per patient and there were no problems as long as the information was there. The only confounding factor I am pretty sure is always present is the intra-individual variability confounded with the inter-individual variability. Serge Guzy President POP-PHARM Head Pharmacometrics and Preclinical Statistics;XOMA