Table 6 The barriers and facilitators mapped to the consent and ethics theme

Some disabilities may directly limit an individual’s ability to receive, comprehend, and use information about a clinical trial to provide informed consent [39]. Amongst these are sensory impairments, cognitive impairments, or communication difficulties [34, 41]

Where comprehension issues exist, communicating information through more accessible means has shown success. Examples include simplified and tailored consent forms, periodic quizzing of subjects, progressive disclosure strategies and trialled participation [27]

In cases where proxies are used, there is a risk of gatekeeping from carers, clinicians and institution managers [37, 43] resulting in the consent process being less of a reflection of patient priorities

Easing potential sources of anxiety, including patient’s advocates, and exploring patient priorities to reduce risk of coercion has been recommended [16, 43]

Direct contact between investigators and institutionalised disabled groups is restricted on the ethical grounds of right to protection however this can inadvertently deny them of their rights to hear about and get involved in research [37]

Empowering patients to contribute to decision making where possible when proxy consent is being used avoids gatekeeping. Having a sliding scale of required capacity for example, ensures that direct patient consent is considered as far as possible when the risk level is low enough to accommodate limited comprehension [27]

Formation of research committees to oversee involvement of vulnerable institutionalised individuals who have fewer advocates will also protect right to inclusion [33]