Matthew Kobylinski 1 2, Nina Krupa 1 2, Hollis Tam 1, Linda Nguyen 1, Julia R Jahansooz 1 2, Kylie Herndon 1 3, Kaelyn Pacpaco 1 4, Masako Matsunaga 2, Samuel Toh Kim 1, Qi Zhi 1, Michael Sonson 1, 5, Chathura Siriwardhana 2, Enrique Carrazana 2, Kore Liow 1 2
1Memory Disorders Center and Alzheimer’s Research Unit, Hawaii Pacific Neuroscience, Honolulu, HI, USA.
2John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA. 3The University of Cincinnati, Cincinnati, OH, USA. 4Iolani School, Honolulu, HI, USA. 5Cedars Sinai Medical Center, Los Angeles, CA, USA.
Introduction
Equitable representation in Alzheimer’s disease (AD) clinical trials is essential to ensure that research findings apply to diverse populations. However, recruitment patterns often reveal disparities across racial and ethnic groups.
A recent retrospective study examined recruitment of Native Hawaiian and Pacific Islander (NHPI) participants across Alzheimer’s clinical trials in Hawai‘i and utilized ZIP code-based choropleth maps as a visual tool to better understand geographic and demographic patterns .
Study Objective
The study aimed to:
- Quantify recruitment of NHPI participants from 22 Alzheimer’s disease clinical trials conducted over five years.
- Use choropleth maps to visually analyze where recruited participants were located within Hawai‘i.
- Identify potential geographic gaps to improve equity and diversity in future AD clinical trials.
By mapping recruitment patterns geographically, researchers sought to inform more targeted and culturally informed outreach strategies.
Methods
A retrospective chart review was conducted at a dual-site origin clinical trial center in Hawai‘i.
Inclusion Criteria:
- Diagnosis of mild cognitive impairment
- Participation in one or more Alzheimer’s disease clinical trials conducted between 2020 and 2024
Data Collected:
- Self-identified race/ethnicity
- Age
- Residence
- Number of clinical trials participated in
Participants were categorized by ZIP codes as defined by the U.S. Census Bureau. Statistical differences across racial and ethnic groups were assessed using Pearson’s Chi-squared test or Fisher’s exact test .
Results
Total Participation
- 244 patients participated in 22 AD clinical trials between 2020 and 2024.
- 169 patients (69%) provided race/ethnicity information.
- 75 patients (31%) did not provide race/ethnicity information.
Participation by Race/Ethnicity (Among Those Who Reported)
- White patients: 44%
- Asian patients: 34%
- Native Hawaiian and Pacific Islander (NHPI) patients: 15%
Geographic Patterns
Choropleth maps created from ZIP code data revealed geographic trends in recruitment. Notably, findings suggested that NHPI participants were under-recruited from the west side of O‘ahu .
Why Choropleth Maps Matter
Choropleth maps allow recruitment data to be visualized geographically rather than just numerically. This method provides:
- Clear identification of areas with higher or lower participation rates
- Insight into community-level representation
- A foundation for targeted recruitment strategies
By mapping participation data, researchers can identify underrepresented communities and adjust outreach efforts accordingly.
Implications for Future Clinical Trials
The study demonstrates how visual geographic analysis can support more equitable recruitment strategies.
Key implications include:
- Identifying underrepresented populations in specific ZIP codes
- Developing culturally informed recruitment efforts
- Improving diversity in Alzheimer’s disease clinical trials
- Supporting health equity initiatives within Hawai‘i’s communities
Ensuring that clinical trials reflect the diversity of the population is essential for advancing Alzheimer’s research and improving outcomes for all communities.
Conclusion
This retrospective study applied ZIP code-based choropleth mapping to visualize recruitment patterns in Alzheimer’s disease clinical trials in Hawai‘i. Findings revealed disparities in NHPI recruitment, particularly in certain geographic regions.
By utilizing geographic visualization tools, clinical research centers can better understand recruitment gaps and implement targeted strategies to improve representation and equity in future trials .
