Longitudinal studies of ageing: from insights to impacts: commentary to accompany themed collection on longitudinal studies

Innovations in pharmacovigilance studies of medicines in older people

Pharmacovigilance is defined by the World Health Organization as "the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other medicine/vaccine related problem". Pharmacovigilance studies are critical for detecting and assessing adverse events of medicines that may not have been observed in clinical trials. This activity is especially important in older people who are often excluded from clinical trials as they have multiple chronic conditions and use multiple medicines for longer durations than the clinical trials. In this narrative review we describe innovative methods in pharmacovigilance studies of medicines in older people that leverage the increasing availability of digital health technologies, electronic health records and real-world health data to identify and quantify medication related harms in older people.

Intrinsic capacity trajectories, predictors and associations with care dependence in community-dwelling older adults: A social determinant of health perspective

AIMS

To identify intrinsic capacity trajectories, predictors of intrinsic capacity trajectories and associations between intrinsic capacity trajectories and care dependence in community-dwelling older adults in China.

METHODS

A retrospective longitudinal study was conducted, and the data were obtained from a five-year national longitudinal cohort study of older adults in China between 2011 and 2015. The social determinants of health framework informed the data analysis and interpretation.

RESULTS

A total of 3893 older adults met the selection criteria and were included in the study. Three intrinsic capacity trajectories were identified: high trajectory (15.7 %), stable trajectory (52.7 %) and declining trajectory (31.6 %). Social determinants contribute to intrinsic capacity decline in older adults. Decreased cognitive function, psychological status, and locomotion at baseline were associated with care dependence.

CONCLUSION

Approximately thirty percent of the older adults in this cohort study experienced a decline in intrinsic capacity within a 5-year period. Social determinants contributed to this decline in older adults.

'Ageing well': Discursive constructions of ageing and health in the public reach of a national longitudinal study on ageing

Established in 2006, the Irish Longitudinal Study on Ageing (TILDA) investigates the health, economic and social circumstances of a nationally-representative sample of people aged fifty years and older in a series of biennial data collection waves. Irish newspapers have been reporting the results of TILDA for over a decade and a half, and their texts represent reports of scientific research distilled through the pen of journalists. In their totality, their texts constitute a public discourse on ageing and health. Using critical discourse analysis, we examined the discourse within the texts of a purposive sample of two national daily newspapers. As sites of public discourse, newspapers reflect social life and are influential in forming and legitimating public attitudes. Like other sites of discourse, their language-in-use is contextually located, is rarely neutral and may employ strategies to discursively construct, sustain and privilege particular social identities, including ageing identities. Discursively constructed as 'ageing well', our analysis of newspaper texts revealed a discernible meta-discourse on ageing and health in which ageing was framed as a life course stage that may be cultivated, diligently self-nurtured and exploited for its positive aspects. When considered in light of literature on health and social inequalities, the consequences of this broadly positive ageing discourse can, somewhat perversely, frame older adults in unintended negative ways, including homogenising them and attributing to them capacities for ageing well that they may not possess. Discursively constructing older adults as a social and economic resource can also impose unrealistic expectations on them and may legitimise exploitation and demonstrate how normative ideologies of ageism and ableism are conveyed through legitimising language. Despite these potentially unintended consequences, the available media resources associated with TILDA may represent one of the most important contributions of the study, in terms of informing positive public attitudes towards ageing.

An Exploration of Methods to Resolve Inconsistent Self-Reporting of Chronic Conditions and Impact on Multimorbidity in the Canadian Longitudinal Study on Aging

OBJECTIVES

To quantify inconsistent self-reporting of chronic conditions between the baseline (2011-2015) and first follow-up surveys (2015-2018) in the Canadian Longitudinal Study on Aging (CLSA), and to explore methods to resolve inconsistent responses and impact on multimorbidity.

METHODS

Community-dwelling adults aged 45-85 years in the baseline and first follow-up surveys were included (n = 45,184). At each survey, participants self-reported whether they ever had a physician diagnosis of 35 chronic conditions. Identifiable inconsistent responses were enumerated.

RESULTS

32-40% of participants had at least one inconsistent response across all conditions. Illness-related information (e.g., taking medication) resolved most inconsistent responses (>93%) while computer-assisted software asking participants to confirm their inconsistent disease status resolved ≤53%. Using these adjudication methods, multimorbidity prevalence at follow-up increased by ≤1.6% compared to the prevalence without resolving inconsistent responses.

DISCUSSION

Inconsistent self-reporting of chronic conditions is common but may not substantially affect multimorbidity prevalence. Future research should validate methods to resolve inconsistencies.

Potential Role for Herpesviruses in Alzheimer's Disease

Across the fields of virology and neuroscience, the role of neurotropic viruses in Alzheimer's disease (AD) has received renewed enthusiasm, with a particular focus on human herpesviruses (HHVs). Recent genomic analyses of brain tissue collections and investigations of the antimicrobial responses of amyloid-β do not exclude a role of HHVs in contributing to or accelerating AD pathogenesis. Due to continued expansion in our aging cohort and the lack of effective treatments for AD, this composition examines a potential neuroviral theory of AD in light of these recent data. Consideration reveals a possible viral "Hit-and-Run" scenario of AD, as well as neurobiological mechanisms (i.e., neuroinflammation, protein quality control, oxidative stress) that may increase risk for AD following neurotropic infection. Although limitations exist, this theoretical framework reveals several novel therapeutic targets that may prove efficacious in AD.

Study of Longitudinal Aging in Mice: Presentation of Experimental Techniques

Aging is associated with functional and metabolic decline and is a risk factor for all noncommunicable diseases. Even though mice are routinely used for modeling human aging and aging-related conditions, no comprehensive assessment to date has been conducted on normative mouse aging. To address this gap, the Study of Longitudinal Aging in Mice (SLAM) was designed and implemented by the National Institute on Aging (NIA/NIH) as the mouse counterpart to the Baltimore Longitudinal Study of Aging (BLSA). In this manuscript, we describe the premise, study design, methodologies, and technologies currently employed in SLAM. We also discuss current and future study directions. In this large population mouse study, inbred C57BL/6J and outbred UM-HET3 mice of both sexes are longitudinally evaluated for functional, phenotypic, and biological health, and collection of biospecimens is conducted throughout their life span. Within the longitudinal cohorts, a cross-sectional arm of the study has also been implemented for the well-controlled collection of tissues to generate a biorepository. SLAM and studies stemming from SLAM seek to identify and characterize phenotypic and biological predictors of mouse aging and age-associated conditions, examine the degrees of functional and biomolecular variability that occur within inbred and genetically heterogeneous mouse populations with age, and assess whether these changes are consistent with alterations observed in human aging in BLSA. The findings from these studies will be critical for evaluating the utility of mouse models for studying different aspects of aging, both in terms of interpreting prior findings and designing and implementing future studies.

Non-Invasive Biomarkers of Musculoskeletal Health with High Discriminant Ability for Age and Gender

A novel approach to ageing studies assessed the discriminatory ability of a combination of routine physical function tests and novel measures, notably muscle mechanical properties and thigh composition (ultrasound imaging) to classify healthy individuals according to age and gender. The cross-sectional study included 138 community-dwelling, self-reported healthy males and females (65 young, mean age ± SD = 25.7 ± 4.8 years; 73 older, 74.9 ± 5.9 years). Handgrip strength; quadriceps strength; respiratory peak flow; timed up and go; stair climbing time; anterior thigh tissue thickness; muscle stiffness, tone, elasticity (Myoton technology), and self-reported health related quality of life (SF36) were assessed. Stepwise feature selection using cross-validation with linear discriminant analysis was used to classify cases based on criterion variable derived from known effects of age on physical function. A model was trained and features selected using 126 cases with 0.92 accuracy (95% CI = 0.86–0.96; Kappa = 0.89). The final model included five features (peak flow, timed up and go, biceps brachii elasticity, anterior thigh muscle thickness, and percentage thigh muscle) with high sensitivity (0.82–0.96) and specificity (0.94–0.99). The most sensitive novel biomarkers require no volition, highlighting potentially useful tests for screening and monitoring effects of interventions on musculoskeletal health for vulnerable older people with pain or cognitive impairment.

The Impact of Intrinsic Capacity on Adverse Outcomes in Older Hospitalized Patients: A One-Year Follow-Up Study

BACKGROUND

Intrinsic capacity (IC) is a novel view focusing on healthy aging. The effect of IC on adverse outcomes in older hospitalized Chinese adults is rarely studied.

OBJECTIVES

This study focused on investigating the impact of IC domains on the adverse health outcomes including new activities of daily living (ADL) dependency, new instrumental activities of daily living (IADL) dependency, and mortality over a 1-year follow-up.

METHODS

In a retrospective observational population-based study, a total of 329 older hospitalized patients from Zhejiang Hospital in China were enrolled and completed 1-year follow-up. The 5 domains of IC including cognition, locomotion, sensory, vitality, and psychological capacity were assessed at admission. The IC composite score was calculated based on these domains, and the higher IC composite score indicated the greater amount of functional capacities reserved. Multivariate logistic regression models were used to explore the association between IC at baseline and 1-year adverse outcomes.

RESULTS

During the 1-year follow-up, 69 patients (22.5%) experienced new ADL dependency, 103 patients (33.6%) suffered from new IADL dependency, and 22 patients (6.7%) died. After adjusting for age, sex, education level, comorbidities, and polypharmacy, low Mini-Mental State Examination (MMSE) scores at admission predicted 1-year new ADL dependency (odds ratio [OR] = 2.31, 95% confidence interval [CI]: 1.12-4.78) and new IADL dependency (OR = 2.15, 95% CI: 1.14-4.04) among older hospitalized patients, but no significance was obtained between IC domains and mortality. Higher IC composite score at admission was associated with decreased risks of 1-year new ADL dependency (OR = 0.53, 95% CI: 0.40-0.70) and new IADL dependency (OR = 0.76, 95% CI: 0.61-0.95), and 1-year mortality (OR = 0.48, 95% CI: 0.31-0.74) after adjustment for the possible confounders.

CONCLUSIONS

Loss of ICs at admission predicted adverse health outcomes including new ADL and IADL dependency and mortality 1 year after discharge among older hospitalized patients.