And what if the intervention under test aims to change the status quo? The Ekjut intervention in Jharkhand, India, tries to help women in underserved communities to take charge of their health needs. The process itself raises (at least conceptual) notions of empowerment and agency that could be seen as socio-politically destabilizing. How would potential cluster guardians deal with this possibility? More provocatively, how ethical is it to take consent from (mostly male) guardians who embody the social structure within which the participants will be manoeuvring? On balance, we feel that the opt-in nature of the interventions under test relieves us of at least some of the burden of anxiety. Cluster guardianship is less critical if individuals are able to decide for themselves whether to be physically involved in the trial; but perhaps this allows us to skirt the issue.
The number of treatment units (subjects or groups of subjects) assigned to control and treatment groups, affects an RCT's reliability. If the effect of the treatment is small, the number of treatment units in either group may be insufficient for rejecting the null hypothesis in the respective statistical test . The failure to reject the null hypothesis would imply that the treatment shows no statistically significant effect on the treated in a given test . But as the sample size increases, the same RCT may be able to demonstrate a significant effect of the treatment, even if this effect is small.