Priority 1 Question 12

Eldridge et al (2016), in developing a framework to define feasibility and pilot studies in preparation for RCTs, describe feasibility as an overarching concept that can include the following three study types; 1. Randomised pilot studies in which the future RCT, or parts of it, including the randomisation of participants, is conducted on a smaller scale (piloted) to see if it can be done. 2. Non-randomised pilot studies are studies in which all or part of the intervention to be evaluated and other processes to be undertaken in a future trial is/are carried out (piloted) but without randomisation of participants. 3. Feasibility studies that are not pilot studies where investigators attempt to answer a question about whether some element of the future trial can be done but do not implement the intervention to be evaluated or other processes to be undertaken in a future trial, though they may be addressing intervention development in some way.

• “Feasibility is very important. Trials must be possible to do in the real world and without too many restrictive limitations.”
• “Having been involved in various feasibility and pilot studies, I’ve seen how important these can be in terms of informing the design of the main trial. They have highlighted issues to do with variation between clinical sites, (which had implications for how and when participants should be recruited), concerns from staff who would be involved in recruitment regarding time and how to describe the study to potential participants, and reasons for why staff and patients decline to take part.”