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. Author manuscript; available in PMC: 2022 Oct 1.
Published in final edited form as: J Intellect Disabil Res. 2021 Aug 9;65(10):941–948. doi: 10.1111/jir.12877

A Survey Study of the Attitudes and Experiences of Adults with Intellectual Disability Regarding Participation in Research

Nicole E Conroy 1, Katherine E McDonald 2, Robert S Olick 3; The Project ETHICS Expert Panel Members
PMCID: PMC8428784  NIHMSID: NIHMS1738011  PMID: 34369629

Abstract

Background:

Historically, people with intellectual disability have been exploited in and excluded from scientific research. To facilitate greater representation of adults with intellectual disability as research respondents, we sought to understand their interest in research participation and factors affecting their willingness to volunteer to participate, such as the core value of trust.

Methods:

Our survey measured attitudes of adults with intellectual disability toward research in general and research specifically involving adults with intellectual disability as respondents, as well as their prior research experiences, trust of researchers, and interest in future research participation.

Results:

Participants reported positive attitudes toward research and strong interest in future participation opportunities, and trust of researchers was positively correlated to both. The belief that ‘research about adults with intellectual disability is very important’ also predicted participants’ interest in future research participation.

Conclusions.

Our findings indicate that adults with intellectual disability support the direct involvement of adults with intellectual disability in research as respondents. Trustworthy rapport with researchers and positive views about research foster greater inclusion of this population.

Keywords: attitudes, research ethics, research participation, community-engaged research, adults with intellectual disability, trust

Historically, adults with intellectual disability have been abused and exploited in scientific endeavors (Freedman 2001; Iacono, 2006). Even with established principles for ethical research in place, researchers continue to grapple with the central challenge of balancing the right to choose to be included in research with the duty to protect adults with intellectual disability from harm (Iacono & Carling-Jenkins 2012). Influenced by the presumption that adults with intellectual disability lack capacity for autonomous choice, researchers have too often erred on the side of protection; as a result, adults with intellectual disability are too often excluded from and underrepresented in research (Feldman et al., 2013; Martino & Schormans, 2018). A related obstacle is overreliance on proxy respondents, rather than direct representation (McDonald & Raymaker 2013). These barriers to direct inclusion as respondents are exacerbated by practical and social challenges associated with the recruitment and participation of adults with intellectual disability in research, including meeting accessibility and accommodation needs, longstanding mistrust of researchers, and formal and informal gatekeeping that preclude access to research participation opportunities (e.g., guardians or service providers withholding information about participation opportunities; Banas et al. 2019; Becker et al. 2004; Sabatello et al. 2019; Swaine et al. 2011). The generation of new knowledge to promote quality of life among adults with intellectual disability requires researchers to move from the scientifically and ethically questionable practice of proxy reporting to directly including adults with intellectual disability as research respondents, thereby fostering opportunities for them to speak for themselves (Carlson 2013; Krahn & Fox 2014; McDonald & Kidney 2012; McDonald & Raymaker 2013; Spong & Bianchi 2018). Increased research voluntarism also requires trust in the research enterprise among adults with intellectual disability (Rubright et al. 2011).

Emerging, smaller-scale research on the perspectives of adults with intellectual disability suggests that they value opportunities for inclusion in research, are interested in participating in research, are able to make their own participation decisions with and without support from others (dependent on their preferences), believe that research about adults with intellectual disability is important and beneficial, and rely on trust and respect in making participation decisions (Haas et al. 2016; McDonald & Kidney 2012; McDonald et al. 2015; Northway et al. 2014; St. John et al. 2018). Yet little is known about how attitudes toward research held by adults with intellectual disability influence how willing they are to participate in research. To better understand how to respectfully and directly include adults with intellectual disability in survey research, we measured attitudes about research participation among adults with intellectual disability and predictors of their willingness to participate in research, using inclusive, participatory research methods.

Methods

Design and Participants

We received university ethics review board approval for this study, which is part of a larger project for which we developed de novo and adapted survey items on ethical, legal, and social issues in research with adults with intellectual disability and compared views among multiple stakeholder groups (McDonald et al., 2016a, 2016b, 2017, 2018); we focus here on survey data from adults with intellectual disability. We used an inclusive, community-engaged approach, collaborating with a 15-member Expert Panel of seven adults with intellectual disability, two people providing services for adults with intellectual disability, two researchers, two ethics review board members, and two family members of adults with intellectual disability on the development of the parent project, Project ETHICS. The Expert Panel was involved in the development of all research procedures and materials, including the language and design of recruitment strategies and materials, consent/assent procedures and documents, and the survey instrument and its administration. During this process, we privileged the priorities of – and accessibility for – adults with intellectual disability, from the perspective of adults with intellectual disability. Based on collaborative decisions made with the Expert Panel, recruitment, survey administration, and empirical data analysis were overseen by the university researchers. Study findings and their implications were discussed with the Expert Panel, who was also involved in the dissemination of other findings via plain language summaries and co-authorship of presentations and peer-reviewed publications. As such, our use of “we” throughout this manuscript reflects the collaborative, co-researcher roles of university researchers and Expert Panelists through the development and execution of Project ETHICS.

To participate, adults with intellectual disability had to be at least 18 years old, able to communicate their participation decision and survey responses with or without accommodations, and reside in the United States. We did not accept proxy respondents. We recruited adults with intellectual disability via postal mail, electronic mail, social media, and in-person tablings via organizations and events by and for adults with intellectual disability, with multiple reminder invitations when feasible (Dillman 2011). We screened every participant for eligibility, which included defining ‘intellectual disability’ and clarifying its differences from traumatic brain injury, learning disability, and mental illness, followed by the screening question “Have you ever been told you have an intellectual disability or MR (mental retardation)? You may have heard this from a family member, teacher, or other professional.” Additional prompts and clarification were provided as needed. We obtained consent (and assent for those with guardians) from all participants. We encouraged participants to take time to carefully consider participation and discuss their decision with someone else if desired.

To promote accessibility, we used graphics in all recruitment, consent, and survey materials, built in opportunities for breaks, and provided additional supports as requested (e.g., read aloud in person or over the telephone). Participants completed the survey in-person (42%), online (29%), via telephone (26%), and via postal mail (4%). Participants received a US$40 gift card. The final sample included 101 adults with intellectual disability. One-half of the participants were female and 44% were male (7% did not report gender). Participants reported the following racial and ethnic identities: 81% White, 15% Native American/American Indian, 11% Black/African American, 3.9% Asian, and 1% Native Hawaiian/Pacific Islander; 2% identified as Hispanic/Latino.

Measures

We used a multi-phased (prior research, focus groups, Expert Panel, cognitive interviews; Boateng et al. 2018), inclusive research process (Schwartz & Kramer 2020) to adapt and develop survey items and response scales for clear and understandable language, privileging the feedback from adults with intellectual disability. Each survey instrument was associated with an illustrative graphic and response scale text accompanied by corresponding smiley face images. On all items, participants could skip any item or choose “do not wish to say.”

Attitudes toward research participation of people with intellectual disability.

We adapted five items from the Participation in Research Attitude Scale—a measure of attitudes toward the research participation of adults with intellectual disability previously validated with researchers and ethics review board members (McDonald, Keys & Henry 2008)—deemed most salient to the parent project that measured attitudes about opportunity, choice, and decision-making, as well as the importance of research about adults with intellectual disability in general (see Table 1 for items). For consistency with the original instrument, we asked participants to indicate their level of agreement with each statement on a scale of 1 (disagree strongly) to 6 (agree strongly).

Table 1.

Descriptive statistics for attitudes toward research participation of adults with intellectual disability items

Item M (SD) Range
1. Research about adults with an intellectual disability is very important. 5.55 (0.91) 1–6
2. It is very important that adults with an intellectual disability are in research studies. 5.36 (1.06) 1–6
3. Adults with an intellectual disability want to be in research studies. 5.00 (1.26) 1–6
4. Adults with an intellectual disability should be allowed to make up their own mind about being in research studies. 5.56 (1.01) 1–6
5. Adults with an intellectual disability can make up their own mind about being in research studies. 5.56 (0.91) 1–6
6. Adults with an intellectual disability need help from others to make up their mind about being in research studies 4.27 (1.82) 1–6
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Note. Response options ranged from 1 (disagree strongly) to 6 (agree strongly).

General attitudes toward research studies.

We used three items to measure attitudes toward research in general (adapted from Rubright et al., 2011), including positive views of research, interest in participation, and trust in researchers (see Table 2 for items). For consistency with the original instrument, we asked participants to indicate their level of agreement with each statement on a scale of 1 (disagree strongly/not at all) to 5 (agree strongly/very much).

Table 2.

Descriptive statistics for general attitudes toward research studies items

Item M (SD) Range
1. I have a positive view about research in general. 4.58 (0.73) 2–5
2. Would you like to be in research studies in the future? 4.52 (0.91) 1–5
3. How much do you trust people who do research? 4.18 (1.00) 1–5
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Note. Response options ranged from 1 (disagree strongly/not at all) to 5 (agree strongly/very much).

Past experience with research participation.

We used two items to measure past experience with research studies. For participants who responded “yes” to “have you been in a research study before this one?”, we asked “How much did you like being in other research studies?” on a scale from 1 (not at all) to 5 (very much).

Data cleaning and respondent validation.

To eliminate random responses and bot submissions from analysis, we validated all submissions (e.g., reasonable completion time, verifiable postal address, missing data, logical and correlational internal consistency of responses, and response to a quality control item), retaining only respondents that we determined valid across these quality indicators. Missing data, including responses of “do not wish to say,” were no more than 3% per item, with the exception of one item measuring past research participation (10%).

Analysis.

Because the selected items are not representative of the original measures (McDonald et al. 2008; Rubright et al., 2011), psychometric work on these items is not appropriate, and we analysed data at the item level. Prior to analysis, we confirmed that participant demographics and responses to each measure did not differ based on the modality of participation (in-person, online, telephone, and postal mail).

First, we explored attitudes toward research participation of people with intellectual disability. Next, we explored general attitudes toward research studies and relationships among these items. We also explored how much participants with prior research participation liked those experiences, and, using t-tests, we compared participants with and without prior research experience on their general attitudes toward research studies. Finally, using a hierarchical multiple regression, we tested whether attitudes toward research participation of people with intellectual disability predicted personal interest in future research participation.

Results

Attitudes toward Research

Participants positively endorsed the 6 items measuring attitudes toward research participation of people with intellectual disability adapted from the Participation in Research Attitude Scale. See Table 1 for item means and standard deviations.

Adults with intellectual disability also reported positive general attitudes toward research studies. See Table 2 for item means and standard deviations. Trust in researchers was significantly and positively correlated with having a positive attitude toward research in general (r = .59, p < .001) and interest in future research participation (r = .45, p < .001). Having a positive attitude toward research was also significantly and positively correlated to interest in future research participation (r = .53, p < .001).

More than one-quarter (n = 28; 28%) had past experience with research participation and reported having positive experiences (M = 4.81 out of 5, SD = 0.75), with responses ranging from 1 to 5 (out of 5). Participants with prior research experience were significantly more interested in future research participation (M = 4.96) than those without (M = 4.31), t (69.50) = 4.84, p < .001. Participants with prior research experience (n = 28; M = 4.52) also expressed greater trust in researchers than those without (n = 62, M = 4.08), t (82.94) = 2.48, p < .05. Participants with and without prior research experience did not significantly differ on whether they held positive views of research overall.

Willingness to participate in research

Using hierarchical multiple regression, we tested the ability of one’s attitudes toward research participation of people with intellectual disability (items 1–3 in Table 1) to predict one’s personal interest in future research participation (item 2 in Table 2). We controlled for trust in researchers and attitudes toward research in general (Items 1 and 3 in Table 2). The model as a whole explains 41.1% of the variance in interest in future research participation, and the attitude that “research about adults with intellectual disability is very important” makes a unique, significant contribution to the model (see Table 3).

Table 3.

Attitudinal predictors of research participation interest

Predictor Model 1 Model 2
β Beta β Beta
Positive view of research (control) .51** .40** .40** .31**
Trust of researchers (control) .19* .21* .06 .07
Research about adults with intellectual disability is very important .31* .31*
It is very important that adults with intellectual disability take part in research studies −.09 −.10
Adults with an intellectual disability want to be in research studies .12 .16
Δ F 21.07** 5.29**
Δ R2 .31 .10
F 21.07** 12.74**
R 2 .31 .41
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*

p < .05,

**

p < .01

Discussion

Research studies and new knowledge production relies on volunteers, yet paternalistic overprotection of adults with intellectual disability persists and results in unnecessary exclusion of those interested in research participation. Understanding the influence of attitudes and willingness to participate in research among adults with intellectual disability is critical for increasing their representation as research respondents. In this study, we quantitatively assessed the views of adults with intellectual disability toward research with adults with intellectual disability, in addition to their views toward research participation more generally and influences on those perspectives. By understanding attitudes toward research among adults with intellectual disability as well as factors affecting these views, researchers can better promote effective recruitment and participation among this population and foster greater representation in research.

Our findings suggest that adults with intellectual disability generally believe they should have opportunities to participate directly in research and can make participation decisions with and without support. They hold positive views about research in general and were also generally trusting of researchers. As expected, trust was related to having more favorable views of research participation opportunities for adults with intellectual disability, general views of research, and interest in future research participation. These findings confirm prior qualitative inquiry that trust is essential for making positive research enrollment decisions and feeling comfortable during the research process (Haas et al. 2016; McDonald et al. 2012; McDonald et al. 2016a; St. John et al. 2018). Importantly, researchers can build trust using strategies such as providing intellectual disability-tailored recruitment and study materials in accessible formats, answering questions about the study, presuming consent capacity, giving time to consider participation decisions, assessing consent capacity in ways that are perceived as respectful and are calibrated to risks, and allowing opportunities for support from others (Becker et al. 2004; Ho et al. 2017; Taua, Neville & Hepworth 2014); we used these strategies in this project and found they fueled success. Similarly, we found that adults with intellectual disability with prior research experience generally were more interested in future research participation opportunities and expressed greater trust in researchers. These findings suggest that willingness to be a research volunteer is further strengthened through positive research experiences.

We also found that the belief that research with adults with intellectual disability is important is a strong and unique predictor of willingness to participate in research. Knowing this information can help researchers identify individuals who are motivated and likely to participate, potentially saving important project resources (McDonald, Conroy & Olick. 2016b; Rubright et al. 2011). Since this attitude is highly associated with behavioural intention, it may also be an important target for intervention as not all individuals understand the value of and safeguards associated with research participation. Together, our findings suggest that increased research opportunities for adults with intellectual disability and increased familiarity with the research process may facilitate greater trust in researchers, both of which are related to more favorable views toward research with adults with intellectual disability and research in general. Our findings also indicate that adults with intellectual disability value making their own decisions about research participation, which may include seeking support of their own choosing in the decision-making process.

This study had several limitations. We relied on convenience sampling via regional and national organisations by and for this population. It is possible that adults with intellectual disability connected to such organisations differ from those who are not, and their willingness to participate in this study may be associated with more favorable attitudes compared to those who did not participate. Similarly, some research suggests that people with intellectual disability tend to choose the most positive response options in Likert-type scales, especially for individuals with more severe intellectual disability (Hartley & Maclean 2006). However, we saw variability in responses within and between respondents in our study. We also implemented several recommendations for reducing such response bias, including creating and modifying survey instruments with adults with intellectual disability, conducting cognitive interviews with adults with intellectual disability prior to implementation to improve reliability and validity, using pictorial representations for responses, clarifying questions for participants, and building rapport with participants to facilitate trust at the start of the survey when administered in person or on the phone (Hartley & Maclean 2006; O’Keeffe et al. 2019). Finally, it is possible that our inclusion criteria reduced the likelihood of recruiting adults with significant support needs, or that those with more negative prior research participation may have been less likely to participate in our study. As such, the high scores reported by participants in our study may be more of an artifact of self-selection bias than response bias using Likert-type scales.

Limitations notwithstanding, this study fills an important gap in the literature regarding the research participation of adults with intellectual disability and invites future research to explore whether positive attitudes about research and interest in future research results in actual future participation. This study also serves to continue to identify ways scientists can engender understanding of the value of being a research volunteer and trust.

Conclusion

Ensuring that adults with intellectual disability have equal access to research participation opportunities increases the likelihood that they, and society, will benefit from the knowledge gained. Our findings indicate that adults with intellectual disability are strongly interested in the direct involvement of adults with intellectual disability in research, personally and in general. Building rapport with researchers and having positive views about research are important factors to consider in encouraging their inclusion in research.

Acknowledgments:

This work was funded by the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health under Award Number R21HD075078 (PI McDonald). The content is solely ours and does not necessarily represent the official views of the funder. The Project ETHICS Expert Panel members are Anna Carroll, Marty Cuddy, Micah Fialka-Feldman, Dan Flanigan, Pat Fratangelo, Lance Gonzalez, Michael Kennedy, Kathleen King, Chris Mansfield, Deb McGowan, Rachel Romer, Margaret Turk, Shquria Velez, Pamela Walker, and Priscilla Worral. We extend our gratitude to–the Self-Advocacy Association of New York State - Central Region, the Madison Motivators, Carolyn Kim, Emily LoBraico, Ellis Prather, Lyndsey Creed, Nicole Schwartz, and Michael Sperling.

Footnotes

Conflict of Interest: None.

Contributor Information

Nicole E. Conroy, University of Vermont, Human Development and Family Studies, 208 Colchester Ave., Burlington, VT 05405.

Katherine E. McDonald, Syracuse University, Syracuse, NY, 13244, USA.

Robert S. Olick, Upstate Medical University.

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