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.

Incorporating human dynamic populations in models of infectious disease transmission: a systematic review.

BACKGROUND: An increasing number of infectious disease models consider demographic change in the host population, but the demographic methods and assumptions vary considerably. We carry out a systematic review of the methods and assumptions used to incorporate dynamic populations in infectious disease models. METHODS: We systematically searched PubMed and Web of Science for articles on infectious disease transmission in dynamic host populations. We screened the articles and extracted data in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: We identified 46 articles containing 53 infectious disease models with dynamic populations. Population dynamics were modelled explicitly in 71% of the disease transmission models using cohort-component-based models (CCBMs) or individual-based models (IBMs), while 29% used population prospects as an external input. Fertility and mortality were in most cases age- or age-sex-specific, but several models used crude fertility rates (40%). Households were incorporated in 15% of the models, which were IBMs except for one model using external population prospects. Finally, 17% of the infectious disease models included demographic sensitivity analyses. CONCLUSIONS: We find that most studies model fertility, mortality and migration explicitly. Moreover, population-level modelling was more common than IBMs. Demographic characteristics beyond age and sex are cumbersome to implement in population-level models and were for that reason only incorporated in IBMs. Several IBMs included households and networks, but the granularity of the underlying demographic processes was often similar to that of CCBMs. We describe the implications of the most common assumptions and discuss possible extensions.

Employment After Parenthood: Women of Migrant Origin and Natives Compared.

Motherhood negatively affects female employment in majority populations across Europe. Although employment levels are particularly low among women of migrant origin, little is known about the motherhood-employment link in migrant populations. This paper investigates whether family formation differentially affects the labour market position of migrant women and their descendants compared to natives. Using longitudinal microdata from the Belgian social security registers, 12,167 women are followed from 12 months before until 48 months after the birth of their first child for the period 1999-2010. Levels of activity (versus inactivity), employment (versus unemployment) and full-time employment (versus part-time employment) are compared between natives and first- and second-generation women of Southern European, Eastern European, Turkish and Moroccan origin. We find that activity and employment levels decrease to a larger extent following the transition to parenthood among women of migrant origin than among natives. With respect to activity levels, differences between second-generation women and natives are largely explained by socio-demographic and pre-birth job characteristics, while differences between first-generation women and natives are not, suggesting that other factors such as tied migration patterns determine labour market attachment among first-generation mothers. With respect to employment levels, unemployment is increasing more among women of migrant origin of both generations than among natives, also when controlling for background characteristics, which signals differential access to stable job positions as well as to family policies. In sum, the results draw attention to the challenge that parenthood creates for mothers of migrant origin in terms of retaining and gaining employment, but also to the role of labour market entry and early career positions.

Educational differentials in cohabitors' marriage intentions at different childbearing stages in seven European countries.

Several studies have looked into the socio-economic gradients of cohabitation and non-marital fertility. According to the theory of the Second Demographic Transition, highly educated individuals can be considered as forerunners in the Western European spread of non-marital family forms after the 1970s. In Central and Eastern Europe (CEE), however, research has provided evidence for a Pattern of Disadvantage where those with the lowest education have been the most likely to adopt such family forms. Hitherto, few studies have considered the educational gradient of the intentions underlying these behaviors. This contribution uses information on marriage and fertility intentions from the Generations and Gender Surveys for seven European countries to assess educational differentials. In Western Europe we observe no strong educational gradients in marriage intentions at any childbearing stage (before, during or following). In CEE countries, however, less educated cohabitors more frequently choose for cohabitation during childbearing.

Reconsidering inequalities in preventive health care: an application of cultural health capital theory and the life-course perspective to the take-up of mammography screening.

While there are abundant descriptions of socioeconomic inequalities in preventive health care, knowledge about the true mechanisms is still lacking. Recently, the role of cultural health capital in preventive health-care inequalities has been discussed theoretically. Given substantial analogies, we explore how our understanding of cultural health capital and preventive health-care inequalities can be advanced by applying the theoretical principles and methodology of the life-course perspective. By means of event history analysis and retrospective data from the Survey of Health Ageing and Retirement, we examine the role of cultural capital and cultural health capital during childhood on the timely initiation of mammography screening in Belgium (N = 1348). In line with cumulative disadvantage theory, the results show that childhood cultural conditions are independently associated with mammography screening, even after childhood and adulthood socioeconomic position and health are controlled for. Lingering effects from childhood are suggested by the accumulation of cultural health capital that starts early in life. Inequalities in the take-up of screening are manifested as a lower probability of ever having a mammogram, rather than in the late initiation of screening.

Economic Cycles and Entry into Parenthood: Is the Association Changing and Does it Affect Macro-Level Trends? Micro-Level Hazard and Simulation Models of Belgian Fertility Trends, 1960-2010.

The association between economic cycles-typically measured in terms of GDP growth or swings in unemployment-and macro-level fertility trends has received ample attention in the literature. Compared to studies that consider macro-level fertility, individual-based models can address the association between economic cycles and specific stages of family formation (e.g. entry into parenthood) more precisely while allowing for structural factors that contribute to fertility postponement. Using population-wide longitudinal microdata from the Belgian censuses we combine discrete-time hazard models of entry into parenthood for the period 1960 to 2010 with microsimulation models to assess whether economic cycles in tandem with educational expansion can account for year-to-year variation in the proportion of women entering parenthood and variation in the pace of fertility postponement at the macro-level. Results indicate that educational expansion has been a structural driver of fertility postponement, whereas the procyclical effect of economic cycles accounts for accelerations and decelerations of fertility postponement throughout the period considered. Microsimulation of macro-level fertility trends indicates that individual-based models predict the annual proportion of women entering parenthood and the mean age at first birth with average errors of prediction below 1 per cent and 3 months, respectively, while also showing strong correlations between first differences of observed and simulated time-series. Because the extended observation window encompasses several severe recessions, we test whether the association between economic cycles and entry into parenthood has changed over time and how this affected macro-level trends, discussing several mechanisms that may account for such temporal variation.

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.

Does birth history account for educational differences in breast cancer mortality? A comparison of premenopausal and postmenopausal women in Belgium.

This study investigates the impact of reproductive factors on the association between education and breast cancer mortality in Belgium. The role of reproductive factors has been investigated in several studies, with mixed results. Reproductive factors are either completely or partially responsible for the association between education and breast cancer mortality. The data consist of the 1991 census linked to registration data on cause-specific mortality during the period 1991-1995, including all breast cancer deaths in Belgium during the observation period. The study population includes all women aged 35-79 at time of the census. Age-standardized mortality rates and mortality rate ratios (Poisson regression) are computed for educational groups with and without control for reproductive factors. The population is stratified according to age (women aged 35-49 and 50-79) and according to nulliparity. The relationship between education and breast cancer is significant among postmenopausal women. Breast cancer mortality is higher among the higher educated women. These results are consistent with international findings, the gradient not being negative as in most other causes of death, but positive. Statistical control for parity and age at first birth reduces the association largely. In addition, among nonparous women, differences in breast cancer mortality by education are not consistent and generally not significant. Reproductive factors are largely responsible for the positive association between education and breast cancer mortality among postmenopausal women in Belgium. Among premenopausal women, the relation is not significant, a pattern consistent with international studies.

The gender division of paid work over family formation: Variation by couples' migration background.

Although the gender gap in labour force participation has narrowed considerably in many European countries, life course scholars have shown that the transition to parenthood exacerbates gender inequality in couples' division of paid work. Hitherto, variation by migration background has received limited attention in research on the effect of parenthood on couples' gender division of paid work. This is remarkable given that such heterogeneity is theoretically informative on differential interconnectedness of life course events, but may also inform policy makers on the life course transitions that induce migrant-native differentials in women's labour force participation. This study adopts a life course perspective and uses longitudinal microdata from Belgian social security registers to examine variation in couples' gender division of paid work around family formation by migration background. Taking into account couples' migration background - by considering the origin group and migrant generation of both partners - we identify four patterns of gender dynamics around family formation in couples where at least one partner is of migrant origin. These four patterns emerge from (dis)similarities with native couples with respect to their pre-birth division of paid work on the one hand and their changes in this division around family formation on the other hand. These results highlight that combining an account of couples' division of paid work prior to the birth of a first child with a perspective focussing on how the division of paid work changes around family formation is necessary for a thorough understanding of variation by migration background.

Contextualizing ethnic educational inequality: the role of stability and quality of neighborhoods and ethnic density in second-generation attainment.

This study examines the joint impact of neighborhood structure and ethnic density on the educational attainment of the second generation. Using second-generation samples and a majority reference sample from the Belgian Census, multi-level analysis yields the expected positive effects of neighborhood stability and quality and ethnic density on second-generation school completion. Reflecting the ethnic stratification of the Belgian housing market, majority residential concentration tends to coincide with high neighborhood stability and quality and high completion rates, whereas Moroccan concentrations overlap with low neighborhood quality, and low completion rates. For the Turkish and Italian second generation, neighborhood structure moderates ethnic density effects on school completion, in line with segmented assimilation. Our findings suggest distinct Moroccan, Turkish and Italian incorporation modes which reflect differential access to, and investments in ethnic versus mainstream social networks.

Educational Differences in Cohort Fertility Across Sub-national Regions in Europe.

Educational differences in female cohort fertility vary strongly across high-income countries and over time, but knowledge about how educational fertility differentials play out at the sub-national regional level is limited. Examining these sub-national regional patterns might improve our understanding of national patterns, as regionally varying contextual conditions may affect fertility. This study provides for the first time for a large number of European countries a comprehensive account of educational differences in the cohort fertility rate (CFR) at the sub-national regional level. We harmonise data from population registers, censuses, and large-sample surveys for 15 countries to measure women's completed fertility by educational level and region of residence at the end of the reproductive lifespan. In order to explore associations between educational differences in CFRs and levels of economic development, we link our data to regional GDP per capita. Empirical Bayesian estimation is used to reduce uncertainty in the regional fertility estimates. We document an overall negative gradient between the CFR and level of education, and notable regional variation in the gradient. The steepness of the gradient is inversely related to the economic development level. It is steepest in the least developed regions and close to zero in the most developed regions. This tendency is observed within countries as well as across all regions of all countries. Our findings underline the variability of educational gradients in women's fertility, suggest that higher levels of development may be associated with less negative gradients, and call for more in-depth sub-national-level fertility analyses by education.

Local Childcare Availability and Dual-Earner Fertility: Variation in Childcare Coverage and Birth Hazards Over Place and Time.

The theoretically well-grounded hypothesis that the availability of formal childcare has a positive impact on childbearing in the developed world has been part of the population literature for a long time. Whereas the participation of women in the labour force created a tension between work and family life, the increasing availability of formal childcare in many developed countries is assumed to reconcile these two life domains due to lower opportunity costs and compatible mother and worker roles. However, previous empirical studies on the association between childcare availability and fertility exhibit ambiguous results and considerable variation in the methods applied. This study assesses the childcare-fertility hypothesis for Belgium, a consistently top-ranked country concerning formal childcare coverage that also exhibits considerable variation within the country. Using detailed longitudinal census and register data for the 2000s combined with childcare coverage rates for 588 municipalities and allowing for the endogenous nature of formal childcare and selective migration, our findings indicate clear and substantial positive effects of local formal childcare provision on birth hazards, especially when considering the transition to parenthood. In addition, this article quantifies the impact of local formal childcare availability on fertility at the aggregate level and shows that in the context of low and lowest-low fertility levels in the developed world, the continued extension of formal childcare services can be a fruitful tool to stimulate childbearing among dual-earner couples.

Interpersonal violence against children in sport in the Netherlands and Belgium.

The current article reports on the first large-scale prevalence study on interpersonal violence against children in sport in the Netherlands and Belgium. Using a dedicated online questionnaire, over 4,000 adults prescreened on having participated in organized sport before the age of 18 were surveyed with respect to their experiences with childhood psychological, physical, and sexual violence while playing sports. Being the first of its kind in the Netherlands and Belgium, our study has a sufficiently large sample taken from the general population, with a balanced gender ratio and wide variety in socio-demographic characteristics. The survey showed that 38% of all respondents reported experiences with psychological violence, 11% with physical violence, and 14% with sexual violence. Ethnic minority, lesbian/gay/bisexual (LGB) and disabled athletes, and those competing at the international level report significantly more experiences of interpersonal violence in sport. The results are consistent with rates obtained outside sport, underscoring the need for more research on interventions and systematic follow-ups, to minimize these negative experiences in youth sport.

Economic recession and first births in Europe: recession-induced postponement and recuperation of fertility in 14 European countries between 1970 and 2005.

OBJECTIVES: The economic crisis that emerged after 2008 caused speculation about further postponement of fertility and a recession-induced baby-bust in countries affected by the economic downturn. This paper aims to disentangle short-term and long-term effects of economic context on entry into parenthood and explores variation of postponement and recuperation by age, gender, educational level and welfare state context. METHODS: Random-effects complementary log-log models including macro-level indicators are used to analyse longitudinal microdata on 12,121 first births to 20,736 individuals observed between 1970 and 2005. RESULTS: Adverse economic conditions and high unemployment significantly reduce first birth hazards among men and women below age 30, particularly among the higher educated. After age 30 economic context continues to affect first birth hazards of men, but not for women. Recuperation of fertility is further associated with access to labour markets and entry into cohabiting unions. CONCLUSIONS: The continuing postponement of first births has clear medical consequences and implications for health policies. Preventive policies should take access to labour markets for younger generations into account as an important factor driving postponement.