11-05-2016 11:40 AM
Hi, this may a question posted the wrong forum but I trying here.
If patients are randomzied in a clinical trial one is expecting that both measured and unmeasured baseline covariates are balanced between treated and controls.
My question is how you mathematically/statisticaly can derive that balance is increased when the study popualtion is increasing?
Thanks in advance!
11-05-2016 04:44 PM
In my mind, it goes like this.
Because of randomisation, the expected value of both control and treated groups are the same for all covariates. When the sample sizes increase, the standard errors of estimated means decrease. Thus the expected difference between treated and control group means decreases.