Vision and Hearing Access in Informed Consent Practice for Clinical Research: A Systematic Literature Review

Providing accessible communication and information during informed consent is critical to promoting autonomy and self-determination. Clinical research staff need to be aware of strategies that can be used to tailor consent practices to meet diverse communication preferences and information access needs. This systematic review aimed to identify strategies to enhance information access during the informed consent process and support greater clinical research participation among people with vision and/or hearing differences. Electronic database searches were conducted in Medline (Ovid), Scopus, PsycINFO (Ovid), Embase (Ovid), and CINAHL (EBSCO), with additional studies identified through Google Scholar and citation searching. Eligible studies were peer-reviewed original research published from 2000 onwards that reported qualitative or quantitative findings and focused on the involvement of people with vision and/or hearing differences. The quality of reporting was assessed using the QualSyst and GRADE CERQual approaches. Findings were deductively mapped to the Consolidated Framework for Implementation Research (CFIR) and its related logic model. A meta-aggregation approach was then used to synthesize findings into generalizable statements, termed ‘Principles’, that reflected the original intent of the included studies. Of 12,121 articles identified, 6,951 publications were screened, 143 underwent full-text review, and 19 studies were included in the final synthesis (15 qualitative and 4 quantitative). Extracted data were categorized as determinants, implementation strategies, mechanisms, and outcomes, with most relating to tailored implementation strategies. Synthesis resulted in eight Principles for enabling information access during an informed consent process, which informed recommendations for practice and policy. These Principles provide guidance for clinical research staff, practitioners, and policy makers seeking to deliver accessible and inclusive informed consent processes and are intended to be adaptable to local contexts and population needs. Future research should evaluate the implementation of these Principles, particularly their acceptability, appropriateness, feasibility, and sustainability. Spanning 25 years of literature, this review provides a roadmap for embedding information accessibility strategies into routine informed consent practice.