Which of the following is not true about non-randomized trials?
Non-randomized trials ( i.e. Those depaing from strict randomization for practical purposes but in such a manner that non-randomization does not seriously affect the theoretical basis of conclusions ( refer pg 81, park 23 rd edition)
Approach of comparability is high
Degree of comparability is high
The experiment can serve as its own control or can utilize a natural control
Several trials may be needed before evaluation is considered conclusive
Epidemiology