Key references on population-level approaches to dementia risk reduction

Population-level interventions for the primary prevention of dementia: a complex evidence review
Walsh S, Wallace L, Kuhn I et al.
Lancet eClinical Medicine, 2024
https://doi.org/10.1016/j.eclinm.2024.102538
Complex, multi-stage, evidence review to identify empirical evidence on population-level interventions for each of the modifiable risk factors identified by the Lancet Commission on dementia (2020). Derives a population-level intervention framework for dementia risk reduction, containing 26 high- and moderate-confidence policy recommendations, supported by relevant information on effect sizes, sources of evidence, contextual information, and implementation guidance.

Benefits of population-level interventions for dementia risk factors: an economic modelling study for England
Mukadam N, Anderson R, Walsh S et al.
The Lancet Healthy Longevity, 2024
https://doi.org/10.1016/S2666-7568(24)00117-X
This paper conducted economic modelling of population level interventions (from Walsh 2024, above) targeting dementia risk factors. We found population-level interventions could help tackle life course dementia risk and save costs with cost savings over indefinite cohorts equating to many hundreds of millions of pounds or even over a billion in some cases.

Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission
Livingston G, Huntley J, Liu K et al.
The Lancet ,2024
https://doi.org/10.1016/S0140-6736(24)01296-0
The most highly cited review series in the dementia prevention field. This Commission of international experts, including PLADRR members identifies 14 potentially modifiable risk factors, for which there is sufficient evidence to support a causal association with dementia. After adjusting for their communality, the global PAF (i.e. the proportion of dementia cases that would be avoided if they were eliminated) for these risk factors is estimated to be 45%. The report also includes a dedicated ‘public health approaches’ section which includes a focus on PLADRR

How many future dementia cases would be missed by a high-risk screening program? A retrospective cohort study in a population-based cohort
Walsh S, Wallace L, Merrick R et al.
Alzheimer’s & Dementia ,2024
https://doi.org/10.1002/alz.14113
Seven out of every ten people who developed dementia during 29 year follow-up of this English population-based sample, would have been classed as ‘normal-risk’ (rather than ‘high risk’) at baseline using the best available dementia risk prediction tools. Eight out of every ten people who were at high risk at baseline did not go on to develop dementia. Even if effective, dementia risk reduction efforts based upon targeted high-risk approaches are therefore unlikely to reduce incidence of disease at the population level.

Universal Prevention of Dementia in Italy: A Document Analysis of the 21 Italian Regional Prevention Plans
Salemme S, Marconi D, Pani S et al.
The Journal of Prevention of Alzheimer’s Disease, 2024
https://doi.org/10.14283/jpad.2024.144
The authors systematically evaluate population-level dementia prevention strategies at the sub-national level in Italy by examining 21 Regional Prevention Plans. This research integrates thorough document analysis with a bespoke quality checklist to categorize 248 interventions based on their direct or indirect focus on the 12 modifiable dementia risk factors identified by the Lancet Commission. While it is notable that all Italian regions tackle physical inactivity, the study points out areas where interventions for dementia-specific risk factors such as traumatic brain injury, hearing loss, and depression can be improved. By uncovering variations between regions and supporting a life-course perspective, this research provides valuable insights, helping to inform and enhance public health strategies and policy frameworks for dementia prevention.

Dementia Prevention and Individual and Socioeconomic Barriers: Avoiding “Lifestyle” Stigma
Wilson, N-A. & Anstey, K.J.
The Gerontologist, 2024
https://doi.org/10.1093/geront/gnad130
Selected as Editor’s Choice, this Forum article discusses the need for greater awareness of individual and socioeconomic barriers to behavior change-oriented dementia risk reduction. Drawing on dementia stigma research and other stigmatized non-communicable diseases, we highlight the potential negative implications from the oversimplification of dementia as a disease caused by poor lifestyle choices. We call for a more balanced approach to dementia health messaging and policy which addresses both individual-level health behaviors and provides more equitable systemic support.

Changes in prevalence and incidence of dementia and risk factors for dementia: an analysis from cohort studies
Mukadam N, Wolters F, Walsh S et al.
The Lancet Public Health, 2024
https://doi.org/10.1016/S2468-2667(24)00120-8
This paper looks at trends in dementia prevalence and incidence as well as trends in dementia risk factors over the same time period. Overall it seems interventions such as compulsory education and reducing rates of smoking through country-level policy changes could be associated with an observed reduction, and therefore future reduction, in the incidence of dementia.

Population attributable fractions of modifiable risk factors for dementia: a systematic review and meta-analysis
Stephan B, Cochrane L, Kafadar A et al.
The Lancet Healthy Longevity, 2024
https://doi.org/10.1016/S2666-7568(24)00061-8
A systematic review and pooled meta-analysis of studies that have estimated PAFs for dementia risk factors. Analyzing data from 74 studies encompassing 61 risk factors, the authors identified that low education, hypertension, hearing loss, physical inactivity, and obesity had the highest pooled population attributable fractions (PAFs) for dementia. Specifically, when considering the combined effect of seven key risk factors—low education, midlife hypertension, midlife obesity, smoking, physical inactivity, depression, and diabetes—the study estimated that up to 55% of dementia cases could be attributed to these factors, with a weighted PAF of 32% after accounting for overlapping risks. This research underscores the significant potential for dementia prevention through public health interventions targeting these modifiable factors. It also highlights the greater impact of such risk factors in low- and middle-income countries, emphasizing the need for tailored prevention strategies that consider regional differences in risk factor prevalence and healthcare infrastructure.

What is a population-level approach to prevention, and how could we apply it to dementia risk reduction?
Walsh S, Wallace L, Mukadam N, Mytton O, Lafortune L, Wills W, Brayne C
Public Health, 2023
https://doi.org/10.1016/j.puhe.2023.09.019
Compares and contrasts key concepts of ‘population-level prevention’ from the literature, explores related theoretical models and policy frameworks, and applies this to dementia risk reduction. Proposes a definition of population-level risk reduction of dementia, which focusses on the need to change societal conditions such that the population is less likely to develop modifiable risk factors known to be associated with dementia, without the need for high-agency behaviour change by individuals

Are Population-Level Approaches to Dementia Risk Reduction Under-Researched? A Rapid Review of the Dementia Prevention Literature
Walsh S, Wallace L, Mytton O, Lafortune L, Wills W, Mukadam N, Brayne C
The Journal of Prevention of Alzheimer’s Disease, 2023
https://link.springer.com/article/10.14283/jpad.2023.57
Rapid review, quantifying the proportion of contributing interventional evidence to the dementia primary prevention literature that is concerned with either approach. Finding that existing systematic reviews of dementia primary prevention include almost exclusively evidence concerning individual-level interventions, and almost no evidence concerning population-level interventions

The Nairobi Declaration—Reducing the burden of dementia in low- and middle-income countries (LMICs): Declaration of the 2022 Symposium on Dementia and Brain Aging in LMICs
Maestre G, Carrillo M, Kalaria R et al.
Alzheimer’s & Dementia, 2023
https://doi.org/10.1002/alz.13025
Position paper from the Symposium on Dementia and Brain Aging in Low- and Middle-Income Countries. Calls for engaging and influence of policymakers and advocacy organisations to encourage implementation and evaluation of population-level dementia risk reduction interventions at a more diverse, global level

Exploring English policymakers’ attitudes towards dementia risk reduction: A qualitative study
Walsh S, Roscoe H, Mattie E, Wallace L, Govia I, Brayne C
International Journal of Geriatric Psychiatry, 2023
https://doi.org/10.1002/gps.6009
Qualitative study involving semi-structured interviews with dementia prevention policymakers to explore their attitudes towards dementia risk reduction, and the balance between individual- and population-level approaches

What would a population-level approach to dementia risk reduction look like, and how would it work?
Walsh S, Govia I, Peters R, Stephan B, Wilson N, Wallace L, Anstey K, Brayne C
Alzheimer’s & Dementia, 2023
https://doi.org/10.1002/alz.12985
Describes what a population-level dementia risk reduction approach could look like, barriers and facilitators to success, and how we should go about achieving it. Includes 10 strategic goals to achieve population-level dementia risk reduction and protection enhancement, targeted at researchers, professionals, funders, science communicators, governments, businesses, and policy makers.

The Potential of Social Policies in Preventing Dementia: An Ecological Study Using Systematic Review and Meta-Analysis
Bodryzlova Y, Mehrabi F, Bosson A et al.
Journal of Aging & Social Policy, 2023
https://doi.org/10.1080/08959420.2023.2245672
In an ecological study with a meta-analysis, the probability of not having clinical dementia despite moderate brain pathology (Braak & Braak stages III-IV) was inversely associated with the Gini index for disposable income, poverty rate, and directly associated with certain public expenditures on healthcare. Not having clinical dementia with advanced AD brain pathology (Braak & Braak stages V-VI) was only associated with public expenditures for long-term care. Thus, social policies may play a role in maintaining and sustaining cognitive health among older people with AD.

Social determinants of modifiable dementia risk in Māori and Non-Māori: Results of the New Zealand Health, Work and Retirement study
Rohr S, Gibson R, Alpass F et al.
Alzheimer’s & Dementia, 2023
https://doi.org/10.1002/alz.074406
This study investigates how social determinants of health influence modifiable dementia risk among midlife and early late-life adults in New Zealand. Utilizing the Lifestyle for Brain Health (LIBRA) index—which encompasses factors such as physical inactivity, smoking, and depression—the research reveals that higher dementia risk scores correlate with lower cognitive function across both Māori and Non-Māori populations. Notably, area-based socioeconomic deprivation is significantly associated with increased dementia risk among Māori but not Non-Māori, while factors like employment status and neighborhood safety impact Non-Māori more. These findings underscore the necessity for equity-focused public health strategies that address the distinct social and environmental factors contributing to dementia risk in different ethnic groups.

The challenge of dementia prevention trials and the role of quasi-experimental studies
Lindhout J, Willem van Dalen J, van Gool W et al.
Alzheimer’s & Dementia, 2023
https://doi.org/10.1002/alz.13029
As an alternative to RCTs, rarely feasible in the dementia prevention space, this paper advocates for the use of quasi-experimental study designs, such as natural experiments and instrumental variable analyses, which can leverage real-world data to infer causal relationships between modifiable risk factors and dementia outcomes. This approach aims to bridge the gap between observational studies and RCTs, enhancing the evidence base for effective dementia prevention strategies.

A whole-population approach is required for dementia risk reduction
Walsh S, Govia I, Wallace L, Richard E, Peters R, Anstey K, Brayne C
Lancet Healthy Longevity, 2022
https://www.thelancet.com/journals/lanhl/article/PIIS2666-7568(21)00301-9/fulltext
A summary of the rationale for population-level approaches to dementia risk reduction from the founding members of this research group. Includes direct comparisons of what individual-level and population-level policies against each of the modifiable risk factors can look like.

What do we mean by population-based approaches to dementia risk reduction?
Transcript of the IRNDP Symposium at ADI 2022
Walsh S, Anstey K, Peters R, Wilson N-A, Lin F, Stephan B, Richard E, Govia I, Brayne C
IRNDP symposium at ADI transcript
This is a summary of the key points raised at the symposium sponsored by IRNDP at ADI 2022 entitled: ‘What do we mean by population-based approaches to dementia risk reduction?’, held on the 10th of June 2022.

From Plan to Impact V. WHO Global Action Plan: The Time to Act is Now
Alzheimer’s Disease International, 2022
https://www.alzint.org/u/From-Plan-to-Impact-V.pdf
The chapter on risk reduction (chapter 3), of this major global report on dementia research, opens with an essay from members of the PLADRR research group. The essay explains the importance of population-level approaches to dementia risk reduction, and explores how we might apply such approaches moving forwards.

A systematic review of the cost-effectiveness of population-level and community-level interventions to reduce the modifiable risk factors of dementia
Walsh S, Brain J, Mukadam N, Anderson R, Greene L, Govia I, Kuhn I, Anstey K, Knapp M, Stephan B, Brayne C
Maturitas, 2022
https://www.maturitas.org/article/S0378-5122(22)00197-9/fulltext
A systematic review describing economic evaluations of population-level interventions that reduce dementia’s risk factors

World Alzheimer’s Report 2022, Expert Essay: Population-based approaches to prevention
Walsh S, Wallace L, Brayne C
https://www.alzint.org/resource/world-alzheimer-report-2022/
The chapter on dementia risk reduction (chapter 23), of this major global report on dementia research, includes an expert essay from members of the PLADRR research group. The essay explains the importance of population-level approaches to dementia risk reduction, and explores how we might apply such approaches moving forwards.

The relevance of social and commercial determinants for neurological health
Walsh S*, Merrick R*, Brayne C. *Joint first authors
The Lancet Neurology, 2022
https://doi.org/10.1016/S1474-4422(22)00428-8
Summarises theory and evidence about how social and commercial determinants affect neurological health, including dementia, across the lifecourse

Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies
Bodryzlova Y, Kim A, Michaud X et al.
Scandinavian Journal of Public Health, 2022
https://doi.org/10.1177/14034948221110019
There is a significant association between social class and the risk of dementia, with education and occupation as the most relevant indicators. In contrast, the link between income and dementia risk appears to be insignificant, and the limited number of studies examining neighbourhood factors precluded adjusted analysis. Investigating the relationship between disadvantaged social class and dementia risk may be a promising avenue for reducing dementia incidence over time. However, narrowly defining social class using only education, occupation, and income may limit the ability of such research to inform effective social policy.

Differences in the potential for dementia prevention between major ethnic groups within one country: A cross sectional analysis of population attributable fraction of potentially modifiable risk factors in New Zealand
Ma’u E, Cullum S, Cheung G et al.
The Lancet Regional Health Western Pacific, 2021
https://doi.org/10.1016/j.lanwpc.2021.100191
This study used national health/administrative datasets from New Zealand to assess how modifiable risk factors for dementia vary across New Zealand’s major ethnic groups. It found that Māori and Pacific peoples have higher potential for dementia prevention (51.4% and 50.8% respectively) compared to Europeans (47.6%) and Asians (40.8%), primarily due to higher rates of obesity and hearing loss, highlighting the need for culturally tailored public health strategies.

How can urban environments support dementia risk reduction? A qualitative study
Rohr S, Rodriguez F, Siemensmeyer R et al.
International Journal of Geriatric Psychiatry, 2021
https://doi.org/10.1002/gps.5626
This qualitative paper explores how features of urban environments can be designed or modified to help reduce the risk of dementia. Through interviews and focus groups, the study identifies key supportive factors such as accessible green spaces, walkability, social connectivity, and age-friendly infrastructure that promote physical activity, cognitive engagement, and social inclusion.

Twenty-seven-year time trends in dementia incidence in Europe and the United States
Wolters F, Chibnik L, Waziry R et al.
Neurology, 2020
https://n.neurology.org/content/neurology/95/5/e519.full.pdf
This pooled analysis of several cohorts across Europe and the USA shows that dementia incidence rate declined by 13% over the preceding 25 years. This is a key finding that indicates dementia risk can be reduced at a population level.

Using natural experiments to evaluate population health and health system interventions: new framework for producers and users of evidence
Craig P, Campbell M, Deidda M et al.
The BMJ, 2025
https://doi.org/10.1136/bmj-2024-080505
This paper presents an updated framework developed by the UK Medical Research Council and the National Institute for Health and Care Research. This framework offers comprehensive guidance on designing, conducting, and interpreting natural experimental evaluations, emphasising the integration of mixed methods, stakeholder involvement, and the use of routinely collected data to assess the impact of population health interventions.

Estimating Dementia Risk Using Multifactorial Prediction Models
Kivimaki M, Livingston G, Singh-Manoux A et al.
JAMA Network Open, 2023
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2805965
Examines the performance of four dementia risk prediction models in the UK Biobank Cohort. Finds that, at a 5% false-positive rate, 84%-91% of incident dementia cases occurring over the next 10 years were missed by the models.

The structural and social determinants of Alzheimer’s disease related dementias
Adkins-Jackson, George K, Besser L.
Alzheimer’s & Dementia, 2023
https://doi.org/10.1002/alz.13027
Employ Bronfenbrenner’s ecological systems theory as a framework to posit how social determinants impact dementia risk and outcomes

A blueprint for dementia research
World Health Organization, 2022
https://iris.who.int/bitstream/handle/10665/363341/9789240058248-eng.pdf?sequence=1
This strategy document from WHO calls explicitly for more evidence into population-level dementia risk reduction research, citing work from PLADRR. It also sets out a strategic goal: “By 2030, to have established evidence of efficient interventions on health, environmental and social determinants that reduce the risk for dementia throughout the life course.”

Optimising brain health across the life course: WHO Position Paper
World Health Organization, 2022
https://iris.who.int/bitstream/handle/10665/361251/9789240054561-eng.pdf?sequence=1
This position paper from WHO outlines key determinants of brain health across the lifecourse, such as healthy environments, which are recognised social determinants of health that would require population-level interventions to address.

Tackling NCDs: ‘best buys’ and other recommended interventions for the prevention and control of noncommunicable diseases
The World Health Organization, 2017
https://apps.who.int/iris/handle/10665/259232
In this document, the World Health Organization summarise the interventions which have the best evidence for being cost-effective for the protection of non-communicable diseases. Though dementia itself is not a direct target of this work, several of the proposed modifiable risk factors from the Lancet Commission (including: obesity, physical inactivity, smoking, excess alcohol, diabetes, and hypertension) are directly considered here. The majority of the interventions labelled as ‘best buys’ are population-level interventions.

The Principles of Population-Level Approaches to Dementia Risk Reduction (PLADRR) – The Auckland Consensus
Estimated publication date, 2025/26

A scoping review of dementia primary prevention policies in England – do they balance reach and agency?
Estimated publication date, 2025

A systematic review of the association between lifecourse socio-economic status and dementia
Estimated publication date, 2025

A scoping review of social determinants of dementia
Estimated publication date, 2025