Kindly guide me how to go about multilinear regression in R for RCT data with two groups. We compared the two means by student 't' test and found significance between the two means. If I would run the regression model to find out the relationship between the dependant variable and the three or four independent variables, how to analyse in R - whether the variables to be entered in to the model for all participants as one group or I need to run separate regression model for each group