All are example for randomised control trials except -
Ans. is 'a' i.e., Natural experiments Types of randomized controlled trials Clinical trials 3. Risk factor trials 5. Trial of etiological agents Preventive trials 4. Cessation experiment 6. Evaluation of health services Types of nonrandomized trials. Uncontrolled trials Natural experiments Before and after comparison studies
Natural experiments
Clinical trials
Risk factor trials
Preventive trials