Design
The NextGen brain health survey is a cross-sectional survey of young adults aged 18-39 years. The survey protocol was developed by the authors in collaboration with public advisors (patient and public involvement representatives, or PPI) who are young adults with a family history of ADRD or a general interest in brain health.
Population
The survey will be conducted online and made available to individuals aged 18-39 years in any country. Responses will be anonymous. As previous research has primarily focused on Europe, North America, and Australia,2-5 we aim to achieve broad geographical representation, including South America, Africa, and Asia. We will also prioritize recruitment of diverse populations, including racial and ethnic minority groups, individuals with a lower socioeconomic status, those with disabilities and those who are neurodiverse. The survey will initially be made available in English, Spanish, Mandarin Chinese and Hindi, with the potential for further translation. Inclusion criteria are: being aged 18-39 years, sufficient language proficiency to engage with the study, and completion of informed consent. Participants will be recruited using a snowball sampling approach through the NextGen Brain Health Working Group and collaborator networks, including the Global Brain Health Institute (GBHI; www.gbhi.org). GBHI represents a diverse community of over 100 professionals working in brain health from more than 40 countries, as well as expert collaborators, including various brain health and ADRD organizations. The study was approved by the research ethics committee at the University of Edinburgh (ID: 23-EMREC-017).
Measures
The NextGen survey comprises demographics, brain health and ADRD knowledge, risk awareness, exposure to risk factors, and attitudes and motivation towards healthy lifestyle behaviors (see Appendix 1). Demographic variables include age, sex, gender, race, ethnicity, sexuality, education, employment status, country of residence, languages spoken, relationship status and living situation. The remaining sections include a series of Likert-type and multiple response questions. Questions focus on knowledge (e.g., “How much would you say you know about dementia?”), personal experience (e.g., “Do you have a family history of dementia? e.g. a parent, grandparent, sibling, or extended family member diagnosed with the condition”), risk awareness and exposure (e.g., “Here is a list of factors that can influence a person's risk of getting dementia. Please indicate how important you think each factor is.”), and risk reduction (e.g., “At what life stage do you think people should start to take action to improve their brain health?”)
We recruited a panel of young adults based in Europe and North America (n = 6), and Africa (n = 6), as public advisors to provide feedback on the survey design and content. The survey was developed in three phases, with ongoing input from public advisors throughout. First, we developed an initial set of items using existing literature on brain health and ADRD surveys2-7, adapted for the target population. We then conducted focus groups with young adults based in Europe and North America (n = 39; see Table 1) to explore their awareness and understanding of brain health. Focus groups were conducted over Zoom and lasted 1 hour with 6-8 participants per session (see Appendix 2 for interview guide). Importantly, these focus groups included representation from under-represented groups in brain health surveys, with a majority of participants identifying as Black or African American, a small majority of male participants and some with less than university-level education. Common themes from the analysis were used to revise existing items and create new items. Third, we piloted the survey within our networks, including with public advisors, brain health researchers, clinicians, ADRD patient advocacy groups, and research participants. Feedback from these groups was integrated into a final version of the survey.
To enhance reach, we used professional language translation services to translate the survey into Spanish, Mandarin Chinese, and Hindi. Feedback was integrated into a final version of the survey. In addition to language translation, we tailored some items to be more regionally or culturally appropriate. We also made some questions optional, for example, sexuality.
Statistical analysis
Data cleaning and analyses will be conducted in R v4.2.1. Descriptive analyses will be conducted, including distributions of demographic variables and descriptions of all other responses. Answering patterns by groups defined according to demographics will be explored using clustering techniques such as factor analysis and latent variable modeling. Data will be combined to explore a priori research questions; for example, how does motivation towards healthy lifestyle behaviors differ across regions? We will also employ exploratory analysis strategies to assess for unanticipated trends.
We will recruit a minimum sample of 5,000 young adults, consistent with previous brain health surveys (see power calculation below).18 We aim to recruit equal numbers of participants across geographical regions, sex and gender. We also aim to recruit 20% LGBTQIA+ participants, 15% neurodiverse participants and 15% participants with disabilities, in line with global prevalence estimates. We anticipate that these numbers will be adequate to examine our main research question, which is “What is young adults’ level of knowledge and awareness about dementia and their own brain health?” Providing power analyses for all possible research questions is not feasible, however, we can provide some level of statistical power. In a multiple linear regression analysis with eight predictors, R square equal to 0.10, significance level of .05, and a sample size of only 500, the statistical power is >.90 (G*Power v3.1.9.7).