difference in differences statistics ___________ is the difference between the treatment group and the control group. how many patients are affected by the difference? difference between treatment and control difference in differ difference in difference number of units did difference versus control difference in difference number of individual units what is the difference in difference rule in statistics what is the difference in differences in patient population difference in differences number of units difference in difference a test number of units how many units are in the treatment group differences in difference number versus control difference-in-difference definition difference in the differences in the population difference in difference definition what is the difference in the amount of patients compared to the control group? number of patients in different treatment groups? difference-in-difference definition