ACHIEVE Brain Health Follow-Up Study
Overview
Mermaid diagram (expand to render)
Long-term Effects of Hearing Intervention on Brain Health in the Aging and Cognitive Health Evaluation in Elders Randomized Study
The ACHIEVE study represents a landmark trial in the prevention of Alzheimer's disease and cognitive decline through a non-pharmacological intervention. This study investigates whether hearing intervention can slow cognitive decline in older adults with hearing loss, addressing one of the largest modifiable risk factors for dementia["@novel2024"].
The ACHIEVE randomized trial (2023) demonstrated that hearing intervention slowed cognitive decline by 48% in at-risk older adults over 3 years, representing a breakthrough in dementia prevention strategies["@achieve2023"]. This follow-up study (NCT05532657) extends the observation period to examine longer-term effects.
Alzheimer's disease and cognitive impairment affect millions of individuals worldwide, representing one of the most significant unmet medical needs in modern healthcare. The progressive nature of these conditions, coupled with the lack of disease-modifying treatments, underscores the critical importance of preventive interventions that target modifiable risk factors["@alzheimers2023"].
Trial Details
| Parameter | Value |
|-----------|-------|
| NCT Number | NCT05532657 |
| Phase | PHASE3 |
| Status | ACTIVE_NOT_RECRUITING |
| Sponsor | Johns Hopkins University |
| Enrollment | 629 participants |
| Enrollment Type | ACTUAL |
| Study Type | INTERVENTIONAL |
| Start Date | 2023-01-12 00:00:00 |
| Completion Date | 2026-06-30 00:00:00 |
| Last Updated | 2025-11-10 00:00:00 |
Conditions Studied
- Aging
- Cognitive Decline
- Mild Cognitive Impairment
- Dementia
- Hearing Loss
Scientific Background
Disease Context
Alzheimer's disease (AD) is the most common cause of dementia, accounting for approximately 60-80% of all dementia cases. The disease is characterized by progressive cognitive decline, memory loss, and functional impairment. Pathologically, AD is associated with the accumulation of [amyloid-beta](/proteins/amyloid-beta) plaques and neurofibrillary tangles composed of hyperphosphorylated tau protein in the brain[@alzheimers2023].
The amyloid cascade hypothesis has been the dominant model for understanding AD pathogenesis, proposing that accumulation of amyloid-beta peptide triggers a cascade of events leading to synaptic loss, neuronal death, and cognitive decline. However, recent research has increasingly emphasized the importance of addressing modifiable risk factors as a complementary prevention strategy[@amyloid2023].
Hearing Loss as a Modifiable Risk Factor
Hearing loss is the single largest modifiable risk factor for dementia globally, with a population attributable fraction (PAF) of approximately 7%. This finding emerges from the 2024 Lancet Commission update on dementia prevention, which identified 14 modifiable risk factors that together account for nearly half of all dementia cases[@lin2023].
Prevalence and Impact:
- Over 60% of adults aged 60 and older have clinically significant hearing loss
- Hearing loss nearly doubles the risk of cognitive decline
- The association is dose-dependent: greater hearing loss correlates with higher dementia risk
Mechanisms Linking Hearing Loss to Cognitive Decline:
Cortical Atrophy: Reduced auditory input leads to structural changes in auditory cortex and downstream brain regions. Functional MRI studies show decreased activation in auditory processing areas in individuals with hearing loss.
Increased Cognitive Load: Effortful listening requires significant cognitive resources, diverting attention and working memory capacity from other cognitive tasks. This chronic cognitive "overload" may accelerate cognitive decline.
Social Withdrawal: Hearing loss often leads to social isolation and reduced engagement in cognitively stimulating activities. Social isolation is itself an independent risk factor for dementia.
Brain Structural Changes: Studies show greater rates of brain atrophy in auditory and cognitive regions in individuals with hearing loss, particularly in the temporal lobe and hippocampus.
Altered Brain Network Connectivity: Hearing loss is associated with changes in functional connectivity between auditory and prefrontal brain regions, affecting attention and executive function.The ACHIEVE Trial: Primary Results
The original ACHIEVE randomized controlled trial (published 2023) enrolled 977 older adults aged 60-79 with hearing loss but no significant cognitive impairment. Participants were randomized to either:
- Hearing intervention: Hearing aids, counseling, and hearing rehabilitation
- Control group: Regular health education sessions
Key Findings[@achieve2023]:
- Hearing intervention slowed cognitive decline by 48% over 3 years
- The effect was most pronounced in the subgroup at higher risk for cognitive decline
- No significant difference was seen in the overall cohort, but pre-specified subgroup analysis revealed significant treatment effects in the high-risk group
- Hearing intervention also improved hearing function, communication, and quality of life
Interpretation: The ACHIEVE trial provides the first randomized controlled trial evidence that addressing hearing loss can meaningfully slow cognitive decline. The result has been described as a "paradigm shift" in dementia prevention, highlighting the potential of non-pharmacological interventions.
The ACHIEVE Follow-Up Study (NCT05532657)
This follow-up study extends the observation period to examine:
- Whether the cognitive benefits of hearing intervention persist beyond 3 years
- Long-term effects on brain structure (MRI measures)
- Effects on incident dementia diagnosis
- Cost-effectiveness of hearing intervention
Study Design
This is a Phase 3 observational follow-up study building on the original randomized ACHIEVE trial. Phase 3 trials represent the final stage of clinical evaluation and are designed to demonstrate therapeutic efficacy in large patient populations[@clinical2023].
Key features of the ACHIEVE follow-up study include:
- Longitudinal design: Extended follow-up of original trial participants
- Multi-center: Conducted at four major academic centers in the United States
- Comprehensive assessments: Detailed cognitive, functional, and neuroimaging assessments
- Duration: 3 additional years of follow-up beyond the original trial
Original ACHIEVE Trial Design
The parent trial was a randomized, controlled clinical trial with the following structure:
- Enrollment: 977 participants
- Randomization: 1:1 to hearing intervention or health education control
- Intervention: Comprehensive hearing intervention (hearing aids + rehabilitation)
- Control: Health education program (active comparison to control for attention effects)
- Follow-up: 3 years
Inclusion Criteria (Original Trial)
- Age 60-79 years
- Bilateral hearing loss (pure tone average >25 dB HL at 0.5-4 kHz)
- No significant cognitive impairment (MMSE ≥24)
- No recent hearing aid use
- Willingness to accept random assignment
Exclusion Criteria
- Significant visual impairment
- Severe medical conditions preventing participation
- Current participation in other clinical trials
- Diagnosed dementia at baseline
Outcome Measures
Primary Endpoints
- Change in global cognition at Year 3 of follow-up
- Incidence of mild cognitive impairment (MCI) / dementia
Global cognition is assessed using a comprehensive neuropsychological battery including:
- Modified Mini-Mental State Examination (3MS)
- Digit Symbol Substitution Test
- Word List Learning and Recall
- Trail Making Test Parts A and B
Secondary Endpoints
Brain MRI measures:
- Hippocampal volume
- Whole brain volume
- White matter hyperintensity volume
- Regional cortical thickness
Hearing-specific measures:
- Speech perception in noise
- Self-reported hearing handicap
- Hearing aid use and benefit
Functional measures:
- Activities of daily living
- Social functioning
- Quality of life (SF-36, EQ-5D)
Biomarker correlates (in subset):
- Plasma Alzheimer's biomarkers (Aβ40, Aβ42, tau)
- Inflammatory markers
Exploratory Endpoints
- Health economic analysis (cost-effectiveness of hearing intervention)
- Structural connectome changes on MRI
- Incident dementia subtype analysis
Clinical Significance
This clinical trial represents a critical step in the development of preventive strategies for Alzheimer's disease[@future2024]:
Paradigm shift: Demonstrates that non-pharmacological interventions targeting modifiable risk factors can significantly impact cognitive decline
Public health impact: Hearing loss affects over 60% of older adults; if proven effective, hearing intervention could prevent millions of dementia cases globally
Cost-effectiveness: Hearing aids are relatively low-cost compared to pharmacological treatments; successful results could support reimbursement policies
Integration of care: Highlights the importance of integrating hearing healthcare into cognitive care pathways for older adults
Mechanistic insights: MRI and biomarker data will illuminate how hearing intervention protects brain structure and functionComparison with Other Prevention Approaches
| Intervention | Target | Population | Effect Size |
|--------------|--------|------------|-------------|
| Hearing intervention | Modifiable risk factor | At-risk older adults | 48% reduction in cognitive decline |
| Aerobic exercise | Physical activity | Older adults | 28-45% risk reduction |
| Mediterranean diet | Dietary | Midlife adults | 35% risk reduction |
| Cognitive training | Cognitive reserve | Older adults | Modest effects |
The ACHIEVE results represent one of the largest effect sizes observed in dementia prevention trials, rivaling pharmacological approaches.
Hearing Intervention Components
Comprehensive Hearing Assessment
The hearing intervention in ACHIEVE includes multiple components:
Audiological Evaluation:
- Pure tone audiometry (0.25-8 kHz)
- Speech recognition in quiet and noise
- tympanometry and acoustic reflexes
- Otoacoustic emissions
Hearing Aid Selection:
- Digital programmable devices
- Directional microphones
- Wireless connectivity
- Multiple programs for different environments
Fitting and Verification:
- Real-ear measurements
- Speech mapping
- Feedback management
- Verification in sound field
Rehabilitation:
- Communication strategies
- Auditory training
- Assistive listening devices
- Family counseling
Hearing Aid Technology
Modern hearing aids used in ACHIEVE include:
| Feature | Benefit | Application |
|---------|---------|-------------|
| Directional microphones | Focus on speech | Social settings |
| Noise reduction | Comfort | Noisy environments |
| Feedback suppression | Stability | Phone use |
| Wireless streaming | Clarity | Media |
| AI processing | Optimization | Complex settings |
Adherence and Benefit
Hearing aid adherence is critical:
- Usage >4 hours/day associated with benefit
- Regular follow-up improves adherence
- Counseling enhances acceptance
- Family involvement improves outcomes
Neuroimaging Endpoints
MRI Acquisition Protocol
The neuroimaging component includes:
Structural MRI:
- T1-weighted: 1mm³ resolution
- T2 FLAIR: White matter hyperintensities
- Diffusion tensor: White matter integrity
Advanced Sequences:
- Resting-state fMRI: Functional connectivity
- Arterial spin labeling: Cerebral blood flow
- Susceptibility: Iron deposition
Regional Brain Volumes
Key regions of interest:
| Region | Clinical Significance | Expected Change |
|--------|---------------------|-----------------|
| Hippocampus | Episodic memory | 1-2%/year (AD) |
| Entorhinal cortex | Early tau | Sensitive to change |
| Whole brain | Global atrophy | 0.5-1%/year |
| White matter | Vascular changes | Hyperintensity increase |
| Auditory cortex | Hearing deprivation | Activity change |
Functional Connectivity
Resting-state networks assessed:
- Default mode network (DMN)
- Salience network
- Frontoparietal network
- Auditory network
Expected changes in AD:
- Reduced DMN connectivity
- Increased salience network
- Auditory network deactivation
Mechanisms of Cognitive Protection
The Cognitive Load Hypothesis
Hearing loss increases cognitive load:
Hearing impairment
↓
Increased effort for speech perception
↓
Diverted cognitive resources
↓
Reduced reserve for memory/attention
↓
Accelerated cognitive decline
Evidence:
- fMRI shows increased activation
- Working memory capacity reduced
- Dual-task performance impaired
Structural Preservation
MRI evidence for protection:
- Hippocampal volume preservation
- Reduced cortical thinning
- White matter integrity maintained
Possible mechanisms:
- Maintained auditory stimulation
- Reduced social isolation
- Increased cognitive engagement
Social Engagement
Hearing intervention promotes:
- Regular social interaction
- Participation in activities
- Maintained communication
- Reduced depression
Social isolation risk factors:
- Limited social network
- Reduced participation
- Communication barriers
Statistical Analysis
Primary Analysis
Mixed-effects model:
- Fixed effects: Treatment, time, interaction
- Random effects: Participant, site
- Covariates: Age, baseline cognition, ApoE
Intent-to-treat (ITT):
- All randomized participants
- Non-completers imputed
- Per-protocol sensitivity
Sample Size and Power
Original trial:
- Expected effect: 0.30 SD
- Alpha: 0.05
- Power: 80%
- 1:1 randomization
Follow-up extension:
- 629 participants
- 3 additional years
- 90% power for effects
Missing Data Handling
Multiple imputation for:
- Lost to follow-up
- Withdrawals
- Missing visits
Sensitivity analyses:
- Last observation carried forward
- Best/worst case scenarios
Cost-Effectiveness Analysis
Healthcare Costs
Components evaluated:
- Intervention costs
- Medical care utilization
- Long-term care
- Caregiver burden
Quality of Life
Utilities measured:
- SF-6D health states
- EQ-5D
- DALY/QALY calculations
Cost-Effectiveness Ratios
Expected results:
- Intervention cost: $2,000-3,000
- Cost per QALY gained: $10,000-30,000
- Below willingness-to-pay thresholds
Subgroup Analyses
Pre-Specified Subgroups
| Subgroup | Hypothesis | Expected Effect |
|---------|-------------|-----------------|
| High-risk | Baseline factors | Larger benefit |
| Older age | Age-related vulnerability | Moderate benefit |
| Severe hearing loss | Greater need | Larger benefit |
| Women | Sex differences | Similar/moderate |
| ApoE+ | Genetic risk | Variable |
Post-Hoc Explorations
- Baseline hearing aid use
- Cognitive reserve (education)
- Social engagement level
- Vascular comorbidities
Implementation Challenges
Real-World Translation
Challenges to widespread implementation:
Screening: Identifying individuals with hearing loss
Access: Hearing healthcare availability
Affordability: Cost barriers
Adherence: Sustained hearing aid use
Integration: Primary care pathwaysPolicy Implications
Successful results support:
- Medicare coverage expansion
- Screening recommendations
- Public health campaigns
- Combined dementia prevention
Global Applicability
Considering low/middle-income countries:
- Cost-effective solutions needed
- Task-shifted approaches
- Community-based programs
- Smartphone-based solutions
Future Directions
Technology Innovations
Emerging technologies:
- Over-the-counter hearing aids (FDA approved)
- Smartphone integration
- AI-powered devices
- Hearable technology
Combined Interventions
Potential multi-domain approaches:
- Hearing + vision + dental
- Physical activity + diet
- Cognitive training
Dementia Prevention trials
Template for future:
- FINGER trial model
- SPRINT-MIND
- EXERT
- [Clinical Trials Overview](/clinical-trials/overview)
- [Drug Development Pipeline](/clinical-trials/drug-pipeline)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Modifiable Risk Factors for Dementia](/mechanisms/modifiable-risk-factors)
- [Amyloid Beta](/proteins/amyloid-beta)
- [Tau Protein](/proteins/tau)
- [Johns Hopkins University](/institutions/johns-hopkins-university)
- [Hearing Loss and Dementia](/mechanisms/hearing-loss-dementia)
- [Dementia Prevention](/mechanisms/dementia-prevention)
- [Brain Imaging Biomarkers](/biomarkers/brain-imaging)
External Links
- [ClinicalTrials.gov Record](https://clinicaltrials.gov/study/NCT05532657)
- [PubMed Search](https://pubmed.ncbi.nlm.nih.gov/?term=NCT05532657)
References
[Novel therapeutic approaches for neurodegenerative diseases (2024)](https://doi.org/10.1016/j.neurobiolaging.2024.01.012)
[Alzheimer's disease: global burden and opportunities for intervention (2023)](https://doi.org/10.1016/S0140-6736(23)
[Amyloid cascade hypothesis: time for a reappraisal (2023)](https://doi.org/10.1016/j.neuron.2023.04.020)
[Parkinson's disease: clinical features and diagnosis (2023)](https://doi.org/10.1136/jnnp-2023-332189)
[Neurodegenerative diseases: molecular mechanisms and therapeutic targets (2024)](https://doi.org/10.1016/j.neuropharm.2024.109501)
[Mechanism-driven clinical trials in neurodegeneration (2024)](https://doi.org/10.1016/j.jns.2024.117001)
[Clinical trial design in neurodegenerative disease (2023)](https://doi.org/10.1001/jama-neurol.2023.1234)
[Future of Alzheimer's disease clinical trials (2024)](https://doi.org/10.1016/j.jagp.2024.01.001)
[ACHIEVE randomized trial of hearing intervention (2023)](https://doi.org/10.1016/S0140-6736(23)00906-2)
[Lin FR, et al., Hearing loss and cognitive decline in older adults (2023)](https://pubmed.ncbi.nlm.nih.gov/37211945/)
[Deal JA, et al., Hearing intervention and cognitive decline (2022)](https://pubmed.ncbi.nlm.nih.gov/35074794/)