Reviewed by the Help Dementia Editorial Team — our editors review every article for accuracy against guidance from the National Institute on Aging, the Alzheimer’s Association, and peer-reviewed sources.
Decentralized clinical sits at the center of this dementia and brain health question.
Decentralized clinical trial methods are fundamentally changing who can participate in Alzheimer’s disease research and where that research happens. Rather than requiring patients to travel to specialized research centers on rigid schedules, decentralized clinical trials (DCTs) bring study visits to participants through remote monitoring, mobile research units, and community screenings. This shift is opening doors for thousands of patients who previously faced barriers—whether due to distance from trial sites, mobility limitations, or caregiving responsibilities—making it possible for more people with early Alzheimer’s disease and cognitive concerns to contribute to the research that could define the next generation of treatments. The scale of this research landscape is substantial. Currently, 138 drugs are being assessed across 182 clinical trials for Alzheimer’s disease at more than 4,500 trial sites worldwide, with over 50,000 participants enrolled.
The National Institute on Aging supports over 400 active clinical trials on Alzheimer’s disease and related dementias. Yet for decades, the traditional trial model—where participants must visit specialized centers regularly—excluded many people, particularly those in rural areas, older adults with transportation challenges, and communities historically underrepresented in clinical research. Decentralized methods are closing these gaps. One concrete example illustrates how this is working in practice. The TRAILBLAZER-ALZ 3 trial, which assesses donanemab (Kisunla) for preclinical Alzheimer’s disease, uses a full decentralized model that includes mobile research units traveling to communities, pre-screening conducted through centralized call centers, and remote cognitive assessments completed on electronic tablets at home. This approach has made participation feasible for people who could never have traveled to a traditional trial site.
Table of Contents
- What Are Decentralized Clinical Trial Methods and How Do They Expand Study Access?
- How Digital Health Technologies Enable Remote Participation in Alzheimer’s Studies
- Real-World Examples: The TRAILBLAZER-ALZ 3 Trial and Blood-Based Biomarkers
- Overcoming Geographic and Demographic Barriers in Research Participation
- Limitations and Challenges of Decentralized Trial Models
- The Role of Eli Lilly and Kisunla in Advancing DCT Innovation
- The Future of Alzheimer’s Research and Clinical Trial Accessibility
- Conclusion
What Are Decentralized Clinical Trial Methods and How Do They Expand Study Access?
Decentralized clinical trials represent a fundamental restructuring of how research studies are conducted. Instead of centralizing all research activities at specialized medical centers, DCTs distribute study components across multiple settings—participants’ homes, community clinics, mobile research units, and local healthcare providers. This distributed model maintains scientific rigor while removing the logistical obstacles that have historically limited trial participation. The expansion of access through DCTs is documented and measurable. Research shows that remote visits and decentralized components offer broader recruitment and reduce inequalities related to age, geography, and ethnicity. Older adults who might struggle with weekly trips to a research hospital can now participate from home.
Rural populations, who may live hours from the nearest research center, can be screened and monitored through mobile units or telehealth. Younger adults juggling work and caregiving responsibilities for older parents can engage with studies that fit their schedules. For Alzheimer’s research specifically, where participants often have cognitive changes that complicate travel and where many are older adults with additional health conditions, these accessibility improvements matter profoundly. The difference between traditional and decentralized models is more than logistical. In a conventional trial, a participant with early memory concerns in a rural county in Montana might never know that a relevant study exists, let alone be able to participate. In a decentralized trial, that same person might be identified through community screening, pre-screened by phone, and then participate in study visits that come to them or require only minimal travel. The participation rates and demographic diversity that result reflect this expanded reach.
How Digital Health Technologies Enable Remote Participation in Alzheimer’s Studies
Digital health technologies are the backbone making remote participation possible in complex neurological research. Platforms that capture cognitive and functional assessments remotely—through electronic tablets, video visits, and wearable devices—allow researchers to collect meaningful data outside traditional clinic settings without sacrificing quality or scientific validity. These aren’t simplified or secondary measures; they’re the same assessments researchers have used for decades, now delivered through digital channels. The TRAILBLAZER-ALZ 3 trial demonstrates this in action. Participants use electronic tablets at home to complete cognitive tests—assessments that evaluate memory, attention, and processing speed—that researchers can monitor remotely.
A caregiver might help administer the test, or a participant might complete it independently, but the data flows directly to the research team. Mobile research units can visit communities to conduct in-person evaluations when needed, while home visits or local partnerships handle baseline assessments and ongoing monitoring. This combination creates a flexible framework that accommodates different participant needs and circumstances. However, a critical limitation must be acknowledged: digital participation assumes certain baseline technological literacy and access to reliable internet. An older adult living alone in a rural area with spotty broadband connectivity might still struggle to participate even in a “decentralized” trial. Researchers using DCT models must provide support—training on how to use tablets, troubleshooting technical issues, or offering alternative visit formats—to ensure that decentralization genuinely expands access rather than simply shifting barriers from transportation to technology.
Real-World Examples: The TRAILBLAZER-ALZ 3 Trial and Blood-Based Biomarkers
The TRAILBLAZER-ALZ 3 trial represents one of the most comprehensive implementations of decentralized methods in Alzheimer’s research. This trial assesses donanemab’s effectiveness in people with preclinical Alzheimer’s disease—those who have cognitive changes and biomarker evidence of Alzheimer’s pathology but no significant functional decline. The trial’s decentralized design includes community screenings to identify potential participants, centralized call centers handling initial pre-screening to determine eligibility, mobile research units traveling to recruit and evaluate participants, and electronic tablets for remote cognitive assessments. A parallel innovation strengthening these decentralized studies is the use of blood-based biomarkers combined with DCT models.
Rather than requiring participants to travel for lumbar punctures (spinal taps) to measure cerebrospinal fluid biomarkers—an invasive procedure limiting trial participation—researchers can now identify Alzheimer’s pathology through blood tests. Studies have proven that blood-based biomarkers combined with decentralized methods are feasible for recruiting people into preclinical Alzheimer’s disease trials. A potential participant in a remote area can provide a blood sample at a local lab or during a mobile unit visit, with results indicating whether they meet trial criteria without ever needing to travel to a specialized research hospital. This combination—community-based recruitment, blood biomarkers, remote cognitive testing, and mobile research infrastructure—has made trials like TRAILBLAZER-ALZ 3 accessible to diverse populations previously underrepresented in Alzheimer’s research. The practical result is that tens of thousands of additional people can potentially contribute to the evidence about new treatments.
Overcoming Geographic and Demographic Barriers in Research Participation
One of the most significant barriers to clinical trial participation has always been geography. People living in rural areas, small towns, or regions without specialized medical centers have historically been excluded from research opportunities simply because traveling to trial sites was impossible or prohibitively difficult. For Alzheimer’s research, this has meant that trial populations often skew toward those living near major urban research centers, potentially introducing bias into findings about treatment efficacy, safety, and tolerability. Decentralized clinical trials directly address this geographic disparity. Mobile research units can travel regular routes to smaller communities, meeting participants where they live rather than requiring them to come to the research center. Community screenings identify people who might not otherwise interact with the medical system regularly.
For someone living 200 miles from the nearest Alzheimer’s specialist, a mobile unit visiting a local clinic or community center becomes a genuine opportunity to participate. Additionally, DCT models that include home visits or remote monitoring eliminate geography as a barrier altogether for some trial components. Beyond geography, demographic representation in Alzheimer’s research has historically been skewed. Clinical trials have traditionally enrolled disproportionately white, more educated, and urban populations—people who had the means and proximity to participate. This raises fundamental questions about whether findings from predominantly white trial populations apply equally to Black Americans, Hispanic Americans, and other communities with different genetic backgrounds, healthcare access, and experiences with medical research. Decentralized models that remove transportation barriers and engage communities directly have shown the potential to broaden demographic diversity, though achieving truly representative trial populations requires sustained effort beyond logistics alone.
Limitations and Challenges of Decentralized Trial Models
While decentralized clinical trials offer significant advantages, they come with substantial operational and scientific challenges that researchers must navigate carefully. One fundamental tension is that bringing research to participants, rather than having participants come to researchers, can complicate the standardization that rigorous clinical trials require. When cognitive assessments happen on tablets in home settings rather than in controlled clinic environments, variables like background noise, lighting, interruptions, and technological inconsistencies can introduce noise into data. Researchers must develop robust protocols to minimize these variations while still capturing valid information. Training and oversight present another substantial challenge. A clinical research coordinator at a major medical center undergoes extensive training in study procedures, regulatory compliance, informed consent, and data management.
Mobile research units and community-based staff require similar training, but oversight becomes more complex when they’re distributed geographically. Ensuring consistency in how different sites conduct assessments, handle participant questions, and manage complications requires substantial investment in training infrastructure, quality assurance monitoring, and communication systems. When problems arise—a participant has an adverse event, or a staff member makes a protocol deviation—the decentralized structure can complicate quick response. Additionally, decentralized trials may exclude some populations while including others. Someone without reliable internet, those with significant cognitive impairment who cannot interact with electronic tablets, or those in areas where mobile units cannot reach due to geography or infrastructure limitations may find decentralized trials just as inaccessible as traditional models. The decentralized approach works best for people with mild cognitive impairment or preclinical disease—those cognitively intact enough to engage with tablets and participate in remote visits. For people with moderate to advanced dementia requiring in-person supervision for safety, bringing the research to home settings carries different complexities and risks.
The Role of Eli Lilly and Kisunla in Advancing DCT Innovation
Eli Lilly has emerged as a leading innovator in applying decentralized clinical trial methods to Alzheimer’s disease research. The company’s Kisunla (donanemab), a monoclonal antibody targeting amyloid-beta pathology in the brain, is the most frequently investigated drug in Alzheimer’s-specific decentralized clinical trials. This prominence reflects both the drug’s importance in the treatment pipeline and Eli Lilly’s commitment to making participation in its trials accessible to diverse populations. The TRAILBLAZER-ALZ 3 trial exemplifies this commitment. By incorporating mobile research units, community screenings, and remote cognitive assessments, the trial has demonstrated that phase 3 efficacy studies—the final stage before regulatory approval—can be conducted using decentralized methods without compromising scientific validity.
This approach has implications far beyond donanemab. If large, rigorous efficacy trials can succeed with decentralized methods, the model becomes a template for other drug developers and researchers. The infrastructure that Eli Lilly has invested in—the mobile units, the remote assessment platforms, the training systems—sets a standard that can accelerate decentralization across the entire Alzheimer’s research landscape. However, it’s important to recognize that pharmaceutical company-sponsored trials, even those using decentralized methods, operate within business incentives that may differ from academic or government-sponsored research. Companies naturally invest in decentralized methods for drugs they’ve developed, to ensure robust recruitment and successful trials. This focus may not extend equally to all therapeutic approaches or to earlier-stage research questions that lack commercial drivers.
The Future of Alzheimer’s Research and Clinical Trial Accessibility
The trajectory is clear: decentralized methods are becoming the new standard for Alzheimer’s clinical trials, driven by their proven effectiveness in expanding access and improving recruitment. The recent 18th Annual Clinical Trials on Alzheimer’s Disease (CTAD) conference, held in December 2025 in San Diego, featured new data on how observational studies, biomarker analyses, and clinical development programs are incorporating decentralized and digital health approaches. Researchers are documenting not just feasibility but genuine advantages—faster enrollment, more representative populations, higher participant satisfaction—in trials using DCT elements. Looking ahead, the continued integration of blood-based biomarkers, wearable technology, artificial intelligence for analyzing remote cognitive data, and artificial intelligence-augmented community engagement tools will further reduce barriers to participation. Future Alzheimer’s trials may routinely include components where recruitment happens through community partnerships, baseline screening uses home-collected blood samples analyzed with automated biomarker algorithms, ongoing monitoring is done through wearables and remote assessments, and follow-up visits happen in participants’ communities rather than at research hospitals. This evolution promises that trials will increasingly reflect the actual population living with Alzheimer’s disease and dementia concerns—older adults of diverse backgrounds, in diverse settings, with diverse levels of healthcare access.
Yet for this promise to be realized, investment in infrastructure is essential. Mobile research units require funding. Digital platforms require maintenance and updates. Community partnerships require sustained relationship-building and adequate compensation. Training systems require resources. As the number of Alzheimer’s drugs moving through trials increases—with over 138 drugs currently in the pipeline—the research infrastructure must expand accordingly to ensure that decentralization genuinely opens access rather than creating new bottlenecks or introducing new disparities.
Conclusion
Decentralized clinical trial methods are fundamentally expanding who can participate in Alzheimer’s disease research and how that research happens. By bringing study components to participants through mobile units, remote monitoring, community screening, and digital assessments, these methods overcome geographic barriers, reduce inequalities across age and ethnicity, and allow thousands of additional people to contribute to research that could define treatment options for generations to come. The TRAILBLAZER-ALZ 3 trial, blood-based biomarker innovations, and industry leadership from companies like Eli Lilly demonstrate that decentralized methods can maintain scientific rigor while dramatically improving accessibility.
If you or a family member is interested in participating in Alzheimer’s research, the decentralization of trials means that opportunities may now exist in your community or even in your home. Information about active trials is available through the National Institute on Aging’s clinical trials database, and community screening programs—many using decentralized methods—are increasingly reaching beyond traditional research centers to identify eligible participants. The evolving landscape of Alzheimer’s research is becoming more accessible, more equitable, and more reflective of the communities it aims to serve.
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For more, see National Institute on Aging.
