Hi Daniela,
Yes, I have done the same procedure but with creating “numeric” dummies. I assume that you either used the ds.make or the ds.assign function to create the cohort_1 and cohort_2 variables. Another function that could be helpful which is included in version 5 of DataSHIELD is the ds.Boole function which can be used for the creation of dummy variables and has the argument “numeric.output” which you can set to TRUE in order to create dummy variables of class numeric.
Also, please have a look on this topic Conversion of factors to numerics which might affect some of your analysis.
Best wishes, Demetris