Dear all,
If you have binomial data for which the group sizes differ, how do you correct for it in proc glimmix?
For example:
proc glimmix data=name;
class var1 var2;
model y/n=var1 var2 / dist=binomial link=logit;
random randomvariable;
run;
y is for example the number of affected individuals per group that differs in size (n). I have been told that you can correct for this by adding an overdispersion parameter 'random _residual_;' but I am not too confident about this. Anyone have any ideas? Thanks in advance.
You don't need to correct for this -- it is automatically taken care of. Do not use the 'random _residual_" statement for this purpose (this is for overdispersion: high variability than one would obtain with a binomial distribution).
You don't need to correct for this -- it is automatically taken care of. Do not use the 'random _residual_" statement for this purpose (this is for overdispersion: high variability than one would obtain with a binomial distribution).
Thanks, thought it was a bit weird to correct for unequal sizes using an overdispersion parameter. Good to hear a confirmation that it is not necessary to do so.
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