We identified fifty studies (N=1,548,754). 5 key findings →
Design: meta-analysis Participants: 1,548,754 Evidence: high
Full summary, score breakdown and related studies → Original source
Research
27,380 Alzheimer's and dementia studies in plain English, each scored out of 100.
Fourteen cohorts including 726,900 participants were analyzed. 5 key findings →
Design: meta-analysis Participants: 726,900 Evidence: high
Full summary, score breakdown and related studies → Original source
86/100
The meta-analysis showed that hearing impairment is associated with a higher risk of mild cognitive impairment and dementia among older adults. 4 key findings →
Design: meta-analysis Participants: 15,521 Evidence: high
Full summary, score breakdown and related studies → Original source
Electrophysiological and behavioral tests demonstrated strong correlation and accurate hearing impairment detection compared to PTA. 3 key findings →
Design: systematic review Participants: 1,071 Evidence: high
Full summary, score breakdown and related studies → Original source
ACHIEVE-P sets the stage for the full-scale ACHIEVE trial (N = 850, recruitment beginning November 2017), the first randomized trial to determine efficacy of a best practices hearing (vs. successful aging) intervention on reducing cognitive decline in older adults with HL. 1 key finding →
Design: randomized controlled trial Participants: 850 Evidence: high
Full summary, score breakdown and related studies → Original source
77/100
Subjects experiencing multisensory impairments concurrent with visual impairment demonstrated a negative association with cognitive function. 5 key findings →
Design: cohort study Participants: 500,000 Evidence: moderate
Full summary, score breakdown and related studies → Original source
In this cohort study of US Medicare beneficiaries, dual sensory impairment was prevalent in older adults and associated with increased risk of dementia. 5 key findings →
Design: cohort study Participants: 7,562 Evidence: moderate
Full summary, score breakdown and related studies → Original source
76/100
Observational studies suggested an association between hearing impairment and cognitive disorders. 3 key findings →
Design: systematic review Participants: 7,461 Evidence: high
Full summary, score breakdown and related studies → Original source
Impaired odor identification, particularly in the anosmic range, is associated with increased mortality in older adults even after controlling for dementia and medical comorbidity. 3 key findings →
Evidence: moderate
Full summary, score breakdown and related studies → Original source
In this study, hearing loss was positively associated with a risk of dementia, especially in patients aged 45 to 64 years. 5 key findings →
Design: cohort study Participants: 8,135 Evidence: moderate
Full summary, score breakdown and related studies → Original source
72/100
Older adults with hearing loss are at greater risk of dementia than those with normal hearing. 3 key findings →
Design: cohort study Participants: 7,865 Evidence: moderate
Full summary, score breakdown and related studies → Original source
When completed in 2022, Aging and Cognitive Health Evaluation in Elders study should provide definitive evidence of the effect of hearing treatment versus education control on cognitive decline in community-dwelling older adults with mild-to-moderate hearing impairment. 3 key findings →
Design: randomized controlled trial Evidence: high
Full summary, score breakdown and related studies → Original source
Recent research has revealed an association between hearing impairment and dementia. 4 key findings →
Design: longitudinal study Participants: 154,783 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Age-related hearing loss is linked to loneliness and poorer cognitive health, but it remains unclear whether loneliness helps explain associations between hearing difficulties and cognitive performance or dementia, and whether these patterns reflect causal pathways or shared underlying liability. 4 key findings →
Design: longitudinal study Participants: 10,375 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Apparent cognitive deficits based on MMSE scores obtained in test conditions in which audibility is reduced could result in incorrectly identified cognitive loss if clinicians are not alert to hearing loss when patients are evaluated. 2 key findings →
Evidence: high
Full summary, score breakdown and related studies → Original source
71/100
Both HL and depression are independent risk factors for eventual conversion to dementia. 2 key findings →
Design: longitudinal study Participants: 8,529 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Hearing loss is highly prevalent in dementia; however, people with dementia are less likely to use hearing aids consistently than people with intact cognition are. 2 key findings →
Design: randomized controlled trial Evidence: high
Full summary, score breakdown and related studies → Original source
71/100
HI and VI at baseline were reported by 30.3% and 16.6% of individuals, respectively. 5 key findings →
Design: cohort study Participants: 3,497 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Of 1,164 participants (mean age 73.5 years, 64% women), 580 (49.8%) had mild hearing impairment and 196 (16.8%) had moderate/severe hearing impairment. 5 key findings →
Design: longitudinal study Participants: 1,164 Evidence: moderate
Full summary, score breakdown and related studies → Original source
The combinations of hearing and proprioceptive impairment and hearing, vision, and proprioceptive impairment, were positively correlated with cDVR (β = 0.087 and p = 0.036, β = 0.110 and p = 0.018, respectively). 3 key findings →
Design: longitudinal study Participants: 174 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Overall, 7124 participants representative of Medicare beneficiaries 65 years or older were included. 5 key findings →
Design: cross-sectional Participants: 7,124 Evidence: moderate
Full summary, score breakdown and related studies → Original source
Where “Free full text” comes from
Free full text links and the Full text may need a subscription label come from Unpaywall, Europe PMC and OpenAlex records of free copies, checked 10 Oct 2026. A study with neither is unknown, not paywalled. Show only studies that are free to read
How the 0–100 score works — and why some entries are capped
This is alzhub's own score. It is not an official metric, not an impact factor, and no journal, publisher or ranking body endorses it. We built it so that a reader who is not a scientist can tell a landmark trial from a conference abstract without having to already know the difference. Every point comes from one of 20 components, all of them printed on the study itself, so you can disagree with our arithmetic rather than having to trust the total.
- Journal tier up to 10 pts
- Journal's citation record up to 4 pts
- Study design up to 12 pts
- Strength of evidence up to 5 pts
- Peer-review validation up to 10 pts
- How recent up to 5 pts
- Sample size up to 4 pts
- Effect reported up to 3 pts
- Studied in people up to 3 pts
- Randomised / blinded up to 2 pts
- Times cited up to 7 pts
- Citations per year up to 5 pts
- Impact for its field and year up to 6 pts
- Cited by studies here up to 6 pts
- Still being cited up to 4 pts
- Senior author's track record up to 4 pts
- Institution's track record up to 3 pts
- Multi-centre collaboration up to 3 pts
- Indexed in PubMed up to 2 pts
- Free to read up to 2 pts
Journals are placed in ordered tiers, never given a numeric impact factor — we could not verify current impact factors from a source we control, and an invented one would be worse than none. Tier 1 is the top-tier general journals (NEJM, The Lancet, JAMA, Nature, Science, Nature Medicine); tier 2 is the leading specialty journals; tier 3 is every other peer-reviewed journal. A separate part scores how much the journal's own papers are cited, which tells the tier-3 journals apart.
Two rules we don't bend. First, we never fill in a missing value: if a record does not state a sample size or a design, that component scores zero, and if we simply have no data for a part, such as a citation count, that part is left out and the study is scored on the parts we could check. The study card says which. Second, anything that is not a peer-reviewed article is capped at 16/100 and carries a warning chip — so a conference abstract or a company press release can never outrank a peer-reviewed paper, no matter how good it looks.
We rank a rigorous null result — a good trial showing that something does not work — above an early positive finding. Someone deciding whether to buy a supplement is served by that, and the rigour is already counted by the design and journal components.
The score is computed from the published data alone and is reproducible: the same file always yields the same numbers.
See the whole rubric drawn out → — four charts covering all 27,380 studies: how the scores are spread and where the cap bites, which of the 20 components the library is strong and weak on, which subjects rest on stronger evidence, and what kinds of study each subject is actually built from.
What this library is — and isn't
This is a large sample of the Alzheimer's literature, not an exhaustive index of it. It holds 27,380 records, built mostly from automated pulls of Europe PMC (60.6% of the library) and OpenAlex (18.6%), plus smaller pulls from PubMed, Crossref and medRxiv. If a study, a drug, or a finding isn't here, that is not evidence it doesn't exist in the literature — it may simply not have been pulled in yet.
1,032 records (3.8% of the library) are not peer-reviewed — 962 of those are preprints posted before any journal review, and the rest are conference abstracts, regulatory notices and reports. Every study card on this page states its status plainly, and the score above is capped for anything that isn't a peer-reviewed article.
See the full, machine-readable breakdown of this library's coverage →