Barriers and Facilitators to Participation in Psychosocial Research for Adults With Intellectual Disabilities: A Systematic Review.

Almost everyone who took part in the included studies had already agreed to take part in research, so these views come from people who said yes. Adults who decline, or who are never asked, are not represented, and the authors say the findings may not reflect the wider population of adults with intellectual disabilities. Almost half the included papers involved people with mild to moderate intellectual disability, and for the rest the severity is unclear, so these barriers and facilitators may not apply to people with more severe intellectual disability. Over a third of the included papers had McDonald as first or second author, many using similar methods and possibly reporting on the same participants. The authors say this raises questions about how far the findings generalise, particularly for ethics committee and researcher perspectives, and that some barriers and facilitators may be over-represented. Most of the evidence about what helps at the community level comes from one study (Hall et al. 2017). The authors say it needs replicating in other services. No included study identified a facilitator at the policy level, and funders, policymakers, journal editors and commissioners are missing from the literature, even though the review says these groups hold power to enable or block research. None of the included papers examined whether involving co-researchers with intellectual disabilities changes participation, which the authors call an important gap. Some included studies were published more than 10 years ago, so their findings may not reflect current research practice and should be generalised with caution. Wider cultural, social and political factors were under-represented in the included papers, and the authors note that cultural differences in attitudes towards intellectual disabilities are likely to affect research participation.

The authors declare no conflicts of interest and state that they have nothing to report on funding.

Do not conclude that adults with intellectual disabilities cannot or do not want to take part in research. The studies in this review found they were often more willing than families, carers, services and ethics committees assumed, and that their exclusion was seen by them as more harmful than the risks of taking part. The findings also rest largely on people with mild to moderate intellectual disability, so they say little about those with more severe disability.