Question

In at least 12-15 sentences, please explain why it is not always possible for epidemiologists to use an experimental design such as the RCT to test a hypothesis about an exposure on humans. Also as part of this, please use at least one scholarly(peer reviewed) journal article to substantiate your views.

Answer 1

We cannot always use RCT to test a hypothesis about an exposure on humans because :-

1. The result of RCT may not help the individual patients on the basis of their symptomatology.

2. It can be a very time consuming and difficult process and yet not very helpful in real world scenario.

3. Systematic errors are not always avoided. On the basis of interviewer, there's chances of selection bias and interviewer bias where the cases are given more time than control. This can be avoided by giving equal times to both the groups.

4. On basis of subjects taken, there are subject bias like Hawthorne bias, that is, attention bias and recall bias.

5. On the basis of analyser, there are susceptibility bias and misclassification bias.

6. There are ethical problems associated with RCT.

7. The controls taken can be non-compliant, which can adversely hamper the result.

8. There are problems regarding blinding.

9. It's efficacy is questioned when it comes to the investigation of rare diseases and rare adverse effects.

10. If it's performed in one country, it may not work efficiently in other country.

11. There's limited advantages over newer drugs.

12. Expensive.