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发帖数: 60 | 1 I have a score with missing value. The score is on a 0-70 scale and measured
at 4 time points. The missing pattern is not monotonic. The score is not
normally distributed in the sample. it is right skewed with a lot of
subjects having score 0.
Subjects with disease A are likely to have high score. The distribution of
score is close to normal distribution when separating subjects with and
without disease A.
The purpose of the study is to assess relation between disease A and change
of score during follow-up.
I want to use multiple imputation to impute missing value in the score and
usually use SAS at work.
(1) I tried to use PROC MI, MCMC method in SAS, but the multivariate
normal distribution assumption is not satisfied. Can I do multiple
imputation among subjects with and without disease A, separately, and
combine the imputed data to do analysis?
(2) If doing imputation in separte parts of the sample and combining them
for analysis is not valid, which software or procedure is good for
imputation of a variable not normally distributed? |
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