I'm honestly a bit unsure of the proper etiquite for estimating SMRs in an (multiple imputation) MI data set.
Merging with the standardized population with the MI seems to work.
However implementing the command
Code:
strate
following the merge is the issue.

Before I performed the multiple imputation, I used the following code to estimate SMRs:
Code:
strate, smr(mortrate)
With "mortrate" being the rate of mortality in the General Population.

Following MI, I haven't been able to obtain the SMRs.

Code:
mi estimate, cmdok: strate smr(mortrate)
Using the code above, I received error message 101 : factor variables and time-series operators not allowed an error occurred when mi estimate executed strate on m=1

Any inklings would be greatly appreciated.