Trends in living arrangements and their impact on the mortality of older adults: Belgium 1991‒2012

Population age and household structures shape transmission dynamics of emerging infectious diseases: a longitudinal microsimulation approach

Host population demographics and patterns of host-to-host interactions are important drivers of heterogeneity in infectious disease transmission. To improve our understanding of how population structures and changes therein influence disease transmission dynamics at the individual and population level, we model a dynamic age- and household-structured population using longitudinal microdata drawn from Belgian census and population registers. At different points in time, we simulate the spread of a close-contact infectious disease and vary the age profiles of infectiousness and susceptibility to reflect specific infections (e.g. influenza and SARS-CoV-2) using a two-level mixing model, which distinguishes between exposure to infection in the household and exposure in the community. We find that the strong relationship between age and household structures, in combination with social mixing patterns and epidemiological parameters, shape the spread of an emerging infection. Disease transmission in the adult population in particular is to a large degree explained by differential household compositions and not just household size. Moreover, we highlight how demographic processes alter population structures in an ageing population and how these in turn affect disease transmission dynamics across population groups.

Exploring the impact of population ageing on the spread of emerging respiratory infections and the associated burden of mortality

BACKGROUND

Increasing life expectancy and persistently low fertility levels have led to old population age structures in most high-income countries, and population ageing is expected to continue or even accelerate in the coming decades. While older adults on average have few interactions that potentially could lead to disease transmission, their morbidity and mortality due to infectious diseases, respiratory infections in particular, remain substantial. We aim to explore how population ageing affects the future transmission dynamics and mortality burden of emerging respiratory infections.

METHODS

Using longitudinal individual-level data from population registers, we model the Belgian population with evolving age and household structures, and explicitly consider long-term care facilities (LTCFs). Three scenarios are presented for the future proportion of older adults living in LTCFs. For each demographic scenario, we simulate outbreaks of SARS-CoV-2 and a novel influenza A virus in 2020, 2030, 2040 and 2050 and distinguish between household and community transmission. We estimate attack rates by age and household size/type, as well as disease-related deaths and the associated quality-adjusted life-years (QALYs) lost.

RESULTS

As the population is ageing, small households and LTCFs become more prevalent. Additionally, families with children become smaller (i.e. low fertility, single-parent families). The overall attack rate slightly decreases as the population is ageing, but to a larger degree for influenza than for SARS-CoV-2 due to differential age-specific attack rates. Nevertheless, the number of deaths and QALY losses per 1,000 people is increasing for both infections and at a speed influenced by the share living in LTCFs.

CONCLUSION

Population ageing is associated with smaller outbreaks of COVID-19 and influenza, but at the same time it is causing a substantially larger burden of mortality, even if the proportion of LTCF residents were to decrease. These relationships are influenced by age patterns in epidemiological parameters. Not only the shift in the age distribution, but also the induced changes in the household structures are important to consider when assessing the potential impact of population ageing on the transmission and burden of emerging respiratory infections.

Marital Status, Living Arrangements and Mortality at Older Ages in Chile, 2004-2016

The risk of mortality in old age is associated with marital status and living arrangements. There is still little knowledge about this in Latin America. Our objectives are to examine the association between marital status, living arrangements and mortality of older adults (>60 years) in Chile, and to test whether this association varies when demographic, socioeconomic and health factors are included. We used data from the Social Protection Survey, and mortality data were linked to the Civil Registry. We estimate a series of Poisson regression models. Our results show a clear association between marriage and longevity, since even controlling for demographic, socioeconomic and health factors, we found that separated or divorced, widowed, and unmarried people showed higher relative mortality compared to married people (IRR1.24, IRR1.33, IRR1.35, respectively). Considering only living arrangements, the results show that living alone, alone with children, with children and other relatives or in other arrangements is associated with higher mortality (IRR1.22, IRR1.27, IRR1.35, IRR1.35, respectively) compared to those living with their partners and children. However, considering marital status and living arrangements together, we find that survival among older adults was strongly associated with marital status. Marital status continues to be a direct measure of living arrangements among older adults in Chile.

Does Living Alone Affect Self-Perceptions of Aging? Findings From Two Waves of the Health and Retirement Study

The current study examined if living alone is associated with self-perceptions of aging (SPA). The study used two-wave longitudinal data, sampled from the Health and Retirement Study (HRS), and collected in 2014 and 2018. In total, 6506 older adults aged 60–99 years at baseline were followed up with a 4-year lag. Results indicated that there was no significant change in SPA at follow-up regardless of changes in living arrangements. However, at follow-up, there was a significant cross-sectional difference in SPA between older adults who remained in partnership and those who transitioned to living alone due to widowhood or separation/divorce over a 4-year period. Findings suggest that SPA is relatively stable over time and is barely affected by living alone.

Trends in survival of older care home residents in England: A 10-year multi-cohort study

Increases in longevity combined with a policy emphasis on caring for older people in their own homes could have widened or narrowed the survival gap between care home and community-dwelling resident older people. Knowledge of pre-COVID-19 trends in this gap is needed to assess the longer-term impacts of the pandemic. We provide evidence for England on recent trends in 1, 2 and 3-year mortality amongst care home residents aged 65+ compared with similar community-dwelling residents. We use the Clinical Practice Research Datalink, a nationally representative primary care database. For each of the ten years from 2006 to 2015, care home and community-dwelling residents aged 65+ were identified and matched in the ratio 1:3, according to age, gender, area deprivation and region. Cox survival analyses were used to estimate mortality risks for care home residents in comparison with similar community-dwelling people, adjusting for age, gender, area deprivation and region. The study sample consisted of ten overlapping cohorts averaging 5495 care home residents per cohort. Adjusted mortality risks increased over the study period for care home residents while decreasing slightly for matched community-dwelling residents. The relative risks (RRs) of mortality associated with care home residence were higher for younger ages and shorter follow-up periods, in all years. Over the decade, the RRs increased, most at younger ages and for shorter follow-up periods (e.g. for the age group 65-74 years, 1-year average RR increased by 61% from 5.4 to 8.8, while for those aged 85-94 years and over, 3-year RR increased by 22% from 1.3 to 1.6). Thus the survival gap between older care home and community-dwelling residents has been widening, especially at younger ages. In due course, it will be possible to establish to what extent the COVID-19 pandemic has resulted in further growth in this gap.