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

All 13 included studies used convenience samples, and all but one were observational, so none of this shows that any consent approach works better than another. Only two of the 13 papers systematically studied the quality and outcomes of their own consent approach. Five of the 13 papers came from one survey dataset of 101 adults, and several came from the same principal investigator, so the themes rest on fewer independent groups than the manuscript count suggests. The review covers only US social-behavioral research. The authors say findings may differ for genetic or other biomedical research, which they describe as more ethically complex, and for research outside the US. The studies involved community-dwelling adults who could communicate for data collection or take part in an intervention, and only three papers noted including people with mild to moderate intellectual disability, so people with more significant support needs are barely represented. Consent capacity assessment in the reviewed studies focused almost entirely on whether people understood the study, and much less on undue influence or on using the information to reach an individual decision. Little in the literature addresses researchers' own training and skills in working with adults with intellectual disability, or what meaningful assent looks like.

The authors state they have no conflicts of interest to disclose. No funding source is named in the text provided.

Do not treat these as tested practices. The authors are recommending approaches rather than reporting ones shown to work: only two of the 13 papers systematically checked how well their own consent process performed, and the single study that compared consent formats had groups that differed before it started, so its result is not clean.