Responsible inclusion: A systematic review of consent to social-behavioral research with adults with intellectual disability in the US

Background: In recognition of their status as a health disparities population, there is growing emphasis on conducting research inclusive of adults with intellectual disability to generate new knowledge and opportunities to improve health and equity. Yet they are often excluded from research, and human research participant protection experts and researchers lack agreement on effective consent protocols for their inclusion. Objective: We sought to identify approaches to consent in US-based social-behavioral research with adults with intellectual disability. Methods: We conducted a systematic review on approaches to self-consent with adults with intellectual disability published between 2009 and 2023, identified via searching eight databases and reference list hand searches. We identified 13 manuscripts and conducted a thematic analysis. Results: Our analysis identified themes related to guiding principles, strategies to enhance informed and voluntary consent, approaches to consent capacity, involving individuals subject to guardianship, and strategies for expressing decisions and enhancing ongoing decisions. Conclusions: Manuscripts largely reflected an emphasis on identifying approaches to consent that reflect disability rights principles to promote the right to be included and make one's own decisions based on assessment of relevant information, risks and benefits, and to employ reasonable modifications to achieve inclusion. To avoid the risks of exclusion and advance the responsible inclusion of adults with intellectual disability, we make recommendations to align consent approaches anchored in contemporary thinking about human research participant protections, including through integration with disability rights.