Table 7 Quotations for participant-related factors

I believe it is a lack of trust between doctor and patient, bad doctor patient relationship, a lack of trust into the system, language barriers, patients not trusting the protocol or not understanding why joining the study should be beneficial for them. It doesn’t always need to be beneficial, there is considerable altruism in patients from my experience, but then altruistic patients want to understand why they are doing study xyz, and if this information is provided, they join. R24 Representative of patient organization

The main reason I think, sometimes, some studies are too complicated for the patients. Sometimes they are quite full with their cancer history that they have fears and they just… don’t want to focus on other things. In newer studies very often we need a biopsy or repeated biopsies of tumors. It’s difficult to explain that to patients because they don’t have an immediate advantage. I know it’s very interesting and we need data from biopsies, for example for the science. But in the clinic situation, it’s difficult. T8 Principal Investigator of a discontinued trial

Another important reason is that the protocol - it was a randomized controlled treatment trial in diabetes - the protocol was quite intensive for patients. And a major reason why patients participate or do not participate is whether it brings them something new which they do not receive by conventional, usual daily care. So it was not very attractive. T9 Principal Investigator of a discontinued trial

…maybe also complicated protocols- require a lot of time from the patient to participate in the study might be another reason why patients if they have another alternative to the treatment do not participate in clinical study. R29 Representative of Federal Office of Public Health