Demographic Research

Population ageing increases the importance of cognitive capacity for making decisions about retirement and living independently beyond it. We tested whether post-war educational expansion and working-life social mobility eliminate the association between social class of origin and cognition in early old age using the 1958 National Child Development Study. Two outcomes were analysed at age 62: standard episodic memory (immediate + delayed word recall) and long-term episodic memory, capturing accurate half-century recall of childhood household facts (rooms and people at age 11 validated against mothers' responses). Social mobility trajectories derived in prior work were classified into predominantly manual versus non-manual class trajectories. Models were estimated separately for women and men across three specifications: (i) social origin and controls, (ii) adding social mobility, and (iii) adding weighting to address healthy survivor bias. Education was consistently associated with both outcomes. For long-term episodic memory, social origin gradients were clearer than for short-term episodic memory, with men from service/professional origins showing a 13 percentage-point higher probability of accurate half-century recall than men from manual origins. These findings indicate that education expansion and working-life social mobility failed to release the grip of social origin on long-term episodic memory.

Recent progress in mathematical kinship modelling has allowed one to predict the probable numbers of kin for a typical population member. In the models, kin may be structured by age and sex, both in static or time-variant demographies. Knowing the probable numbers of kin in different stages - such as parity, health status, or geographic location - however, remains an open challenge in Kinship Demography. Knowing how population structure delimits kin to distinct stages is an advance - for instance, the probability of having one sister at home and one sister away has different social implications from the probability of having two sisters. We present a novel analytical framework, grounded in branching process theory, that provides kin-number distributions jointly structured by age and stage. Using recursive compositions of probability generating functions (PGFs), we derive the joint age, stage, and age x stage kin-number distributions. All marginal distributions over either dimension naturally emerge. Simple extensions of the PGF approach additionally yield: the joint distribution of an individuals own stage and their kins stage; the probable numbers of kin deaths, both in total and by generation number; and the probabilities of being kinless and/or orphaned. We demonstrate the framework through novel results in an application using UK parity-specific fertility and mortality data. HighlightsO_LIA new method calculates probability generating functions for the number of kin structured by age and stage C_LIO_LIThe model allows predicting the probable numbers of kin organised by age and stage C_LIO_LIRecursive nesting of probability generating functions in branching processes is used C_LIO_LIAn application is presented highlighting the novel results C_LI

This study investigated retirement adjustment in retired police officers in the UK (N = 289), examining how time since leaving the service moderates the relationship between perceived organisational support and retirement adjustment while accounting for resilience. Results indicated a developmental trend: organisational support remains stable initially but becomes increasingly influential in later life. Using Johnson-Neyman analysis, a threshold of 32.07 years was identified, after which the association reaches statistical significance. These findings suggest an organisational legacy effect; for the older generation, the retrospective perception of being valued by the service acts as a durable psychological resource. This study offers a novel conceptualisation of long-term organisational influence by identifying a temporally delayed legacy effect that extends beyond existing models of retirement adjustment. The study advocate for lifelong wellbeing strategies that extend, recognising that the organisational relationship continues to shape adjustment outcomes decades after the conclusion of active duty.

The basic reproduction number of an infectious disease is known to depend on the structure of contacts between individuals in a population. This relationship has been explored mathematically through two well-known models: one which depends on a matrix of contact rates between different demographic groups, and another which depends on the variability of contact rates over the population. Here we introduce a model that combines and generalises these two approaches. We derive a formula for the basic reproduction number and validate it through comparisons to simulated outbreaks. Applying this method to contact survey data collected in Belgium between 2020 and 2022, we find that our model produces higher estimates of the basic reproduction number and larger relative changes over periods when social contact behaviour was changing during the COVID-19 pandemic. Our analysis suggests some practical considerations when using contact data in models of infectious disease transmission.

Objectives: Longer lifespans lead to longer time on retirement, despite the efforts to raise the retirement age. Therefore, it is important to study how the retirement years can be spent without diseases. This study examined socioeconomic and sociodemographic differences in healthy years spent on retirement. Methods: We followed a cohort of retired Finnish municipal employees (N=4231, average follow-up 15.4 years) on national administrative registers for major chronic diseases: cancer, coronary heart disease, cerebrovascular disease, diabetes, asthma or chronic obstructive pulmonary disease, dementia, mental disorders, and alcohol-related disorders. Median healthy years on retirement and age at first occurrence of illness (ICD-10 and ATC-based) in each combination of sex, occupational class, and age of retirement were predicted using Royston-Parmar models. Prevalence rates for each diagnostic group were calculated. Results: Most healthy years on retirement were spent by women having worked in semi-professional jobs who retired at age 60-62 (median predicted healthy years 11.6, 95% CI 10.4-12.7). The least healthy years on retirement were spent by men having worked in routine non-manual jobs who retired after age 62 (median predicted healthy years 6.5, 95% CI 4.4-9.5). Diabetes was slightly more common among lower occupational class women, and dementia among manual working women having retired at age 60-62. Discussion: Healthy years on retirement are not enjoyed equally by women and men and those who retire early or later. Policies aiming to increase the retirement age should consider the effects of these gaps on retirees and the equitability of those effects.

Background Childhood socioeconomic position (SEP) is a key determinant of later life health. Understanding the extent to which adult SEP mediates this association into early old age is important for explaining how health inequalities are propagated across generations and how they might be addressed in later life. To our knowledge, no prospective study has examined whether childhood SEP remains associated with health at the threshold of older age and the extent to which any such association is mediated by adult SEP. Methods We used data from the 1958 British Birth Cohort, a prospective study that has followed participants since birth, drawing on earlier data collected at birth and ages 33 and 55 years and newly collected data from the age 62 sweep. Using interventional causal mediation analyses, we assessed whether adult occupational class, education, housing tenure, and income mediate associations between childhood social class (manual vs non manual) and health at age 62 (self rated health, C reactive protein [CRP], cholesterol ratio, Glycated hemoglobin [HbA1c], and N terminal pro B type natriuretic peptide [NT proBNP]). Findings Associations between childhood SEP and self rated health, CRP, cholesterol ratio, and HbA1c persisted after accounting for adult SEP. Mediation was outcome specific and differed by sex. Among men, occupational class mediated 39% of the association with self rated health (indirect effect RR 0.90, 95% CI 0.86,0.95) and education mediated 27% (0.93, 0.90,0.96). Among women, education mediated 10% (0.95, 0.91,0.98) and housing tenure mediated 6% (0.97, 0.94,0.99). Indirect effects for CRP were smaller, and mediation was minimal for cholesterol ratio, HbA1c, and NT proBNP Interpretation Population level improvements in adult SEP could reduce, but are unlikely to eliminate, later life health inequalities associated with childhood SEP. Reducing these inequalities will require policies that address disadvantage in early life and improve adult financial and employment conditions. Funding UK Economic and Social Research Council

Introduction: Frailty is a dynamic condition associated with increased vulnerability to adverse health outcomes in older adults. While previous research has primarily focused on deficit-based mental health factors, such as depression and loneliness, less is known about the role of positive mental health determinants, including well-being, resilience and social connectedness, in the development and progression of frailty. Understanding both risk and protective factors is essential for informing public health strategies aimed at promoting healthy ageing. This study aims to examine the longitudinal relationship between mental health and frailty in a nationally sampled population of adults aged 50 years and older in Slovenia. Methods and analysis: This longitudinal observational study will collect data at four time points over a two-year period (January 2026-March 2028). A stratified random sample of community-dwelling adults aged 50-84 years will be drawn from the national population registry, with 5,000 individuals invited to participate in the first wave. Frailty, mental health and a set of social, psychological, and health-related factors will be assessed. Data will be analyzed using a combination of descriptive, inferential and longitudinal statistical methods to examine associations between frailty and mental health over time. Potential explanatory factors will also be explored within the longitudinal framework, and additional analyses will assess the impact of attrition. Ethics and dissemination: The study has been approved by the Ethics and Deontology Committee of the National Institute of Public Health. Participation is voluntary, and informed consent will be obtained from all participants. Data will be anonymized and handled in accordance with applicable data protection regulations. Findings will be disseminated through peer-reviewed publications, conference presentations and public health reports to inform strategies for promoting healthy ageing.

Childhood socioeconomic position (SEP) can have lifelong effects on health. Many studies have used adult height as a surrogate marker for early-life conditions. In this study, we derived the non-genetic component of height, calculated as the residual from sex-specific standardized height regressed on genetically predicted height, as a surrogate for childhood SEP, using data from the Hispanic Community Healthy Study/Study of Latinos (2008-2011). A positive residual would indicate favorable early-life conditions promoting growth, while a negative residual indicates early-life adversity that may stunt the development. The height residual was associated with early-life variables such as parental education, year of birth, US nativity and age at first migration to the US (50 states/DC), supporting the validity of height residual as a surrogate for early-life conditions. Furthermore, a height residual was positively associated with better cardiovascular health (CVH) and cognitive function among middle-aged and older adults. Interestingly, among <35 years old, the height residual was negatively associated with the "Lifes Essential 8" clinical CVH scores. These results suggest the non-genetic component of height as a surrogate for childhood environment, with predictive value for CVH and cognitive function.

Abstract Background: Resilience is acknowledged to be an important component for successful aging in older adults, but there is scant evidence with which to inform public health interventions for this age group. The aim of this study is to determine whether the public health intervention, mindfulness for later life is both feasible and acceptable to older adults. Methods: Participants were recruited from September 2021 to June 2022 through older adult organisations and charities, such as the University of the Third Age, Age UK, and Age Concern, and by adverts distributed through village newsletters and support organisations. Participants were offered six weekly sessions of mindfulness therapy, the program was based on the mindfulness-based stress reduction program, each session was two hours long with 10-15 participants per program. The following two pre-defined indicators of success needed to be met for the program to be deemed feasible: successful uptake (recruitment of 30 participants over nine months) and initial engagement. Results: Thirty-three potential participants were screened for eligibility over nine months, 31 of whom were recruited to the study (103% of the target sample). Of these, 28 participants (90%) completed four or more online sessions. Thus, predefined indicators of feasibility were met. Conclusions: This study supports the feasibility of delivering the mindfulness for later life program as a public health intervention, including recruitment and treatment completion. A full-scale trial to assess the clinical- and cost-effectiveness of the intervention including its long-term effects is warranted.

Timeliness of therapy initiation is a fundamental determinant of outcomes for many medical conditions, most importantly, cancer. Yet, existing inefficiencies in healthcare systems mean that delays between diagnosis and treatment frequently adversely affect the clinical outcome for cancer patients. Although estimates of effects of lag time to therapy would be informative to policymakers considering resource allocation to minimize delays in oncology, causal methods are seldom explicitly discussed in epidemiologic analyses of these lag times. Here, we propose causal estimands for such studies, and outline the protocol of a target trial that could be emulated with observational data on lag times. To illustrate the application of this approach, we simulate studies of lag time to treatment under two scenarios: one in which indication bias (Waiting Time Paradox) is present and another in which it is absent. Although our discussion focuses on oncologic outcomes, components of the proposed target trial could be adapted to study delays for other medical conditions. We believe that the clarity with which causal questions are posed under the target trial emulation framework would lead to improved quantification of the effects of lag times in oncology, and hence to better informed policy decisions.

Background Diverse epigenetic clocks are known to capture health risks associated with increased adiposity, but their estimates have never been combined to represent a holistic estimate of biological age acceleration (BAA). There is also a gap in research using epigenetic clocks to study adiposity in lower-middle income Asian countries. Methods and Findings Data from 1,745 participants (21.7{+/-}0.3 years old, 45% female) of the Cebu (Philippines) Longitudinal Health and Nutrition Survey were analyzed. BAA was calculated using PCHorvath 2, PCHannum, PCPhenoAge, PCGrimAge, PCDNAmTL, and DunedinPACE. After ascertaining suitability for factor analysis (Kaiser-Meyer-Olkin 0.81), factor analysis was used to create PCFactorAge. Analogously, FactorAge was created using Horvath, Hannum, PhenoAge, GrimAge, DNAmTL, and DunedinPACE. BMI, waist circumference (WC), and waist-to-height ratio (WHtR) were used to represent adiposity. Linear regression was used to test the association of each adiposity measure with each BAA measure. BMI, WC, and WHtR were positively associated with both BAA combinations: 5 kg/m2 higher BMI corresponded to 0.097 (p=0.015) standard deviation (SD) increase in FactorAge and 0.099 (p=0.004) SD increase in PCFactorAge; 10 cm increase in WC--with 0.091 (p=0.005) SD increase in FactorAge and 0.094 (p<0.001) SD increase in PCFactorAge; 0.1 increase in WHtR--with 0.164 (p=0.001) SD increase in FactorAge and 0.163 (p<0.001) SD increase in PCFactorAge. Additionally, WHtR was associated with meaningful increases in PhenoAge, PCPhenoAge, PCHorvath 2, PCHannum, PCGrimAge, and DunedinPACE. WC was positively associated with PCHorvath 2, PCHannum, PCPhenoAge, and DunedinPACE. BMI was positively associated with PCHannum, PCPhenoAge, and DunedinPACE. Conclusions Our study presents a novel approach to creating a BAA estimate using multiple epigenetic clocks and shows that adiposity measures predict this factor in a young Filipino cohort.

Background: The two-child benefit cap, implemented in April 2017, restricted Universal Credit and Child Tax Credit to the first two children in households with three or more children. We evaluate the impact of the two-child benefit cap on parental mental, general, and financial health, as well as investigate how this may differ in particular sociodemographic and economic subgroups based on sex, ethnicity and income. Methods: Data was obtained from parents (youngest child aged 5 or under) in the UK Household Longitudinal Survey from 2009 to 2023. Outcomes included parental mental health (psychological distress and life satisfaction), general health (health-related quality of life (HRQoL), self-rated health and health satisfaction), and financial health (current financial situation and financial outlook). We used complementary policy evaluation methods with different strengths and assumptions to triangulate evidence and strengthen inference: interrupted time series (ITS), difference-in-differences (DiD) and controlled time series analysis (CITS). Subgroup analyses were stratified by sex, ethnicity, and income. Findings: Across methods, findings consistently indicate that the policy worsened life satisfaction, self-rated health, health satisfaction, and financial health for parents of 3+ children. Findings were less consistent across methods for psychological distress and HRQoL. For instance, for psychological distress ITS and CITS indicate adverse impacts of the policy; however, one DiD model did not support this conclusion due to greater average worsening in the control group between the pre- and post-periods. Subgroup analyses indicate greater mental health and general health impacts in lower income, male and ethnic minority parents; while financial health was negatively impacted in all subgroups examined. Conclusions: Using repeated cross-sectional panel data and triangulating across causal inference methods, we conclude that the two-child benefit cap in the UK had a measurable adverse impact on most health outcomes examined, with worse outcomes for male, lower income and ethnic minority parents.

Although the built environment has been identified as a risk factor for depressive symptoms, it is unclear whether these associations are driven by specific environmental features and whether they remain stable over time. In 10,310 ALSPAC women living in Bristol city, we conducted preregistered network analyses to investigate cross-sectional and longitudinal associations between built environment features (e.g., population density, green space and walkability) and depressive symptoms (at ages 28, 32 and 48 years). Contrary to our hypotheses, associations between individual built environment variables and depressive symptoms were consistently weak. Exploratory factor analyses indicated a built environment factor associated with depressive symptoms at baseline ({beta} = 0.148, p < .001) and 4-year follow-up ({beta} = 0.114, p = .011), but not at 18-year follow-up ({beta} = -0.005, p = .950). These findings suggest the combined influence of built environment features may explain depressive outcomes better than individual built environment measures alone.

ObjectiveThe study aimed to understand the perspectives of professionals from multi-agencies working with individuals experiencing homelessness with complex health and social circumstances (PHECHS), specifically focusing on how they define and contextualise the concept of "complex needs". Methodsixteen qualitative interviews with multi-agencies working with people experiencing homelessness were analysed using Heideggers interpretive phenomenological analysis (IPA), theories of socioeconomic determinants and international and national policy analysis were utilised to analyse data collected by MM on the multi-agency approach to individuals experiencing homelessness with complex health and social needs (PHECHS). FindingsThe analysis of a multi-agency approach aimed at supporting PHECHS revealed that complex needs arise gradually during childhood and can continue into adulthood. A range of factors contribute to both homelessness and these complex needs. Deconstructing the social and economic factors that underpin this continuum is essential to effectively addressing these challenges. This study conceptualises the complex needs of PHECHS into two key themes: deconstructing the PHECHS and attritional approach to PHECHS. ConclusionHomelessness is a grave human rights violation, depriving people of essentials like housing, food, health, education, and social participation. Governments have a moral and legal duty to end homelessness. Real progress demands comprehensive, sustained, and rights-based strategies that tackle root causes--poverty, trauma, and social exclusion. Homelessness also stems from gaps in vital life skills: job seeking, financial management, accessing services, and self-care. These barriers make it even harder to secure stable housing. Lasting reductions in homelessness result from a strong legislative framework, national guidelines, and sustained financial investment. Strengths and limitations of this study1. Employing qualitative methods and analysing data through the lens of socioeconomic determinants of health inequalities enabled the development of a model that clarifies the structural causes of homelessness and highlights key opportunities for preventive policy interventions. 2. Examining the data through the lens of socioeconomic health determinants reveals how systemic and structural factors, such as housing policy and service access, drive complex needs beyond individual circumstances. 3. The study was conducted in an affluent, demographically homogenous city, resulting in the underrepresentation of individuals from ethnic minority backgrounds, women, and young people. 4. Future research should investigate the experiences of people experiencing homelessness using an asset-based perspective, leveraging frameworks that emphasise resourcefulness to promote their meaningful engagement and inclusion in society.

Introduction: Economic opportunity is a core pillar of the American Dream but is not distributed equally across communities. Substantial evidence has identified economic opportunity as an independent social determinant of health, but relatively little is known about opportunity's relationship with other socioeconomic characteristics such as income. Here we address this gap in the literature to examine how area-level economic opportunity modifies the income-health gradient. Methods: We used multivariable ordinary least squares models to estimate the association between self-reported health and economic opportunity across household income levels for working age adults (ages 25-64). Our measures of income and health come from the 2010-2019 Current Population Survey Annual Social and Economic Supplements. Our measure of economic opportunity was drawn from Opportunity Insights and represents the county-averaged national income percentile rank attained in adulthood for individuals born to parents at the 25th percentile of the income distribution. We adjusted for a wide range of individual- and county-level demographic and socioeconomic characteristics. Results: We find that county-level economic opportunity modified the gradient in self-reported health and household income among working-age adults. Effects were particularly pronounced in the lowest income deciles -- an interdecile increase in economic opportunity was associated with closing almost 33% of the gap in health between the lowest and highest income deciles. The results were robust to sensitivity analyses. Conclusion: We show that local area economic opportunity flattens the relationship between household income and health, with lower-income individuals benefitting the most from living in high opportunity areas.

BackgroundPopulation ageing is accelerating, with the fastest growth occurring in low-and middle-income countries. Adequate nutrition is central to healthy ageing, yet little is known about the factors shaping dietary behaviours among older adults in rural African settings, where structural constraints may strongly influence dietary choice. This study explored the facilitators and barriers influencing the dietary choices among older adults aged 60 years and above living in rural communities of Edo Central, Nigeria. MethodsThis exploratory qualitative study was guided by the Socio-Ecological Model (SEM). Semi-structured, in-depth interviews were conducted with 22 older adults. Interview transcripts were analysed thematically using NVivo 14, with findings mapped across individual, environmental, community, and policy/system levels of the SEM. ResultsFourteen subthemes were identified and organised into four overacting SEM domains. Individual drivers identified included a deep knowledge of nutrient-rich diets and a preference for natural, minimally processed foods, as well as community drivers, including cultural and traditional norms and market access, which were the facilitators. Environmental drivers, including physical and economic access, and policy/system drivers, including government policies/subsidies, food prices and inflation, were identified as the main barriers. ConclusionDietary choices among older adults in rural Nigeria are shaped predominantly by structural and food-system constraints rather than by individual knowledge alone. Policies aimed at improving nutrition in ageing populations should prioritise strengthening rural food systems, supporting smallholder agriculture, stabilising food prices, and developing targeted social protection programmes for older adults.

Background Prenatal exposure to pesticides and psychosocial factors often co-occurs, particularly in low- and middle-income settings, yet their joint effects on epigenetic age acceleration (EAA) in early life remain unknown. We investigated the joint associations of prenatal pesticides metabolites and psychosocial factors on EAA in the first five years of life in the South African Drakenstein Child Health Study. Methods In 643 mothers, we measured 11 urinary pesticide metabolites and seven psychosocial factors during the second trimester of pregnancy. Child DNA methylation was measured in whole blood at ages 1, 3, and 5 years. EAA was estimated using the Horvath, Skin & Blood Horvath (skinHorvath), and Wu epigenetic clocks. Longitudinal associations were estimated using generalized estimating equations, adjusted for confounders. Joint mixture associations were evaluated using weighted quantile sum regression (WQS) and quantile g-computation (QGCOMP). Results The joint prenatal exposure mixture was positively associated with Wu ({beta} per one quintile increase in the mixture [95% CI]: 0.41 years [0.15, 0.80]), skinHorvath (0.11 years [0.06, 0.16]), and Horvath EAA (0.31 years [0.20, 0.46]) over time using WQS. Psychosocial factors, particularly food insecurity, physical interpersonal violence, and stress biomarkers, contributed most to the total mixture effect for all clocks. Pyrethroid metabolites PBA and TDCCA were top pesticide contributors to Wu EAA. Pathway enrichment analyses of clock-specific CpGs revealed distinct biological architectures, with the Wu clock enriched for neurodevelopmental and immune pathways, and metabolic pathways for the Horvath clock. Discussion Joint prenatal exposure to pesticides and psychosocial factors was associated with increased EAA across early childhood, with psychosocial factors contributing the most to the total effect. These findings highlight the importance of assessing chemical and non-chemical stressors jointly and clock-specific biological interpretation in epigenetic aging research.

Loneliness--the perceived discrepancy between desired and actual social connection--is a common and aversive psychological state associated with a range of adverse health outcomes. Several theoretical models suggest that these associations may operate partly through health behaviors. In this preregistered study, we used data from the All of Us Research Program to evaluate associations of loneliness and functional rurality (FR), a study-specific contextual index of reduced neighborhood accessibility, with Fitbit-derived physical activity and sleep outcomes. Final samples included 16,912 participants for physical activity analyses and 13,937 for sleep analyses. In adjusted models, higher FR was associated with greater loneliness ({beta} = 0.061, 95% CI [0.045, 0.077], p = 9.63 x 10-14). FR and loneliness were independently associated with fewer daily steps and lower moderate-to-vigorous physical activity. Loneliness was also associated with shorter sleep duration, greater sleep duration variability, higher odds of short sleep, and higher odds of low sleep efficiency. FR was not associated with sleep duration or sleep duration variability but showed a small positive association with mean sleep efficiency and lower odds of low sleep efficiency. Interaction analyses provided little evidence that FR modified the associations of loneliness with most outcomes, although the FR x loneliness interaction was significant for sleep duration variability, indicating that loneliness was more strongly associated with irregular sleep duration in higher-FR contexts. Sensitivity analyses using stricter valid-day thresholds, winsorization, quartile-based exposure coding, and a backward 30-day window yielded directionally similar findings. These results suggest that FR and loneliness are independently associated with lower physical activity, whereas loneliness shows a more consistent relationship with adverse sleep patterns.

Background: Loneliness is common and deleterious to health. Yet little is known about its population burden and health correlates in the US. We aimed to determine the prevalence of loneliness and characterize its health and social functioning correlates among US adults. Methods: With data from the National Health Interview Study (2024), we used survey-weighted Poisson regression to estimate relative risks (RR) and 95% confidence intervals (CI) for frequent loneliness by levels of self-reported general health, social/emotional support, social functioning, and healthcare utilization, adjusted for age, sex, race/ethnicity, number of people in household, marital status, and psychological distress. Results: 12 million US adults reported usually or always feeling lonely, which was associated with worse general health and social/emotional support, work and social participation limitations, and healthcare disengagement. Conclusions: Loneliness affects millions of US adults, with substantial health and social functioning burden.

Background/Objective: Common measures of physical activity (PA) based on duration and intensity do not fully capture its complexity. Adding additional PA components of muscle strength, mechanical strain, and turning actions, can provide a more complete view of activity behavior. Furthermore, PA behaviors differ between men and women. Therefore, the goal of this study is to identify and cluster similar long-term PA patterns over time for each PA component, examined separately for men and women. Methods: We used data from 4963 participants (52% women; mean age 66 years, SD = 8.6) of the Longitudinal Aging Study Amsterdam (1992 to 2019). PA component scores were assigned to self-reported activities, and Sequence Analysis with Optimal Matching was used to identify and cluster similar activity patterns over a period of 10 years, separately for each component and stratified by sex. Results: PA components varied by sex and displayed a unique mix of trajectories, including predominately low, medium, or high activity, increasing or decreasing patterns, and trajectories characterized by early or late mortality. Importantly, trajectories remained independent, indicating that changes in one PA component were not linked to changes in others. Conclusion: Older men and women follow distinct and independent long term PA trajectories across components, underscoring that PA behaviour cannot be described by a single dimension. Significance/Implications: The observed independence and heterogeneity of trajectories suggest that muscle strength, mechanical strain, and turning actions capture meaningful and distinct aspects of PA that are not reflected by traditional measures alone. Future PA-strategies could incorporate these dimensions and acknowledge sex-specific patterns to better reflect natural movement. The independence of components suggests that future interventions should target multiple dimensions, as changes in one component may not translate to others. Such an approach may support more tailored and sustainable PA interventions in later life.