Re: Missing Gender (Categorical values)

From:Nick Holford Subject:Re: [NMusers] Missing Gender (Categorical values) Date: Thu, 01 Aug 2002 07:52:19 +1200 Alan, Alan Xiao wrote: The idea of multiple imputation is to test the effect of SEX under the range of plausible possibilities for the missing SEX covariate. You cannot get something for nothing so I expect the power to detect the effect of SEX is lower than if you had the full data set. On the other hand if you conclude via imputation that SEX has an effect then you are more likely to be correct (assuming the effect of SEX is the truth) than by assuming an intermediate SEX which is guaranteed to be the wrong value for the missing covariate. Your response to Serge Guzy said"I noticed that in Mould et al's paper on topotecan (J Pharmacokinet Biopharm 1998;26(2):207-46), ". Note there are 2 papers cited here. Diane Mould wrote about topotecan in 2002, Mats Karlsson wrote about assumption testing in 1998. I leave Diane and/or Mats to respond to your question... -- Nick Holford, Divn Pharmacology & Clinical Pharmacology University of Auckland, 85 Park Rd, Private Bag 92019, Auckland, New Zealand email:n.holford@auckland.ac.nz tel:+64(9)373-7599x6730 fax:373-7556 http://www.health.auckland.ac.nz/pharmacology/staff/nholford/