To celebrate the achievements of our authors, we have created a free collection of highly cited articles. This collection features papers contributing to our 2021 Impact Factor and more recent papers we feel will promote the journal's future impact.
All of the articles below are free to access until 31 August 2022:
Climate change and population growth will increase vulnerability to natural and human-made disasters or pandemics. Longitudinal research studies may be adversely impacted by a lack of access to study resources, inability to travel around the urban environment, reluctance of sample members to attend appointments, sample members moving residence and potentially also the destruction of research facilities. One of the key advantages of longitudinal research is the ability to assess associations between exposures and outcomes by limiting the influence of sample selection bias. However, ensuring the validity and reliability of findings in longitudinal research requires the recruitment and retention of respondents who are willing and able to be repeatedly assessed over an extended period of time. This study examined recruitment and retention strategies of 11 longitudinal cohort studies operating during the Christchurch, New Zealand earthquake sequence which began in September 2010, including staff perceptions of the major impediments to study operations during/after the earthquakes and respondents’ barriers to participation. Successful strategies to assist recruitment and retention after a natural disaster are discussed. With the current COVID-19 pandemic, longitudinal studies are potentially encountering some of the issues highlighted in this paper including: closure of facilities, restricted movement of research staff and sample members, and reluctance of sample members to attend appointments. It is possible that suggestions in this paper may be implemented so that longitudinal studies can protect the operation of their research programmes.
This article studies to what extent societal processes such as educational expansion, economic modernisation and business cycles have affected the returns to educational certificates of women and men entering the labour market in West Germany. Using longitudinal data, long-term changes in cohort- and period-specific effects on socio-economic status attainment at entry into the labour market are investigated between 1945 and 2008. Analyses demonstrate that the entrants’ average socio-economic prestige scores have clearly risen in the process of modernisation. Despite educational expansion, increasing skill demands for highly qualified graduates resulted in rising rates of returns for the most highly educated entrants across birth cohorts. While educational expansion and economic modernisation have boosted socio-economic returns at entry into the labour market for women from all educational levels, it has not been the case for men with the lowest levels of education. Both educational expansion and rising skill requirements of occupations led to an increasing polarisation of inequality between tertiary educated labour-market entrants and less-qualified school leavers. Educational expansion in West Germany has therefore never exceeded the occupational skill demands at entry into the labour market.
Gaps in language skills by socio-economic status (SES) are already evident before school entry, and these gaps may change over time. After discussing mechanisms of cumulative advantages (‘Matthew effects’) and compensatory effects as well as the relevance of cultural capital and child-related activities in families, this paper tests mechanisms behind changing SES gaps in language skills from age five to nine in Germany. Analysing data from the German National Educational Panel Study with growth curve models, we find widening SES gaps in children’s vocabulary. Children of mothers with low educational attainment show a far below-average increase in skills. The findings are in line with cumulative advantage by status, although initial skills predict their growth over time as well. There are no signs of any type of compensatory effects. Reading aloud to children appears to substantially impact and mediate SES differences in vocabulary progress.
This paper provides an overview of tracking in Israeli upper secondary education and assesses its effect on the attainment of higher education degrees and earnings. Since the early 1970’s, the Israeli education system has gone through three major reforms that profoundly transformed tracking and sorting mechanisms in secondary education. All three aimed at reducing social inequality in educational attainment through structural changes that expanded learning opportunities and replaced rigid top-down sorting mechanisms with concepts of differentiation and choice. Utilising a data set that includes a large representative sample of Israelis born between 1978 and 1981 who were fully affected by the reforms, the analysis shows that there is a clear link between social background and track placement. Track placement, in turn, is associated with attainment of higher education degrees and income. Moreover, tracking mediates a large proportion of the association between parental class and these two adult outcomes. We also show that the low-status academic tracks that replaced the vocational tracks did not improve the life chances of low-achieving students from disadvantaged social groups.
We study the relationship among family background, placements in upper secondary school tracks and labour market outcomes in the comprehensive welfare state of Denmark. We base our study on high-quality data from Danish administrative registers with a focus on the 1986 birth cohort, which allows us to examine very fine-grained measures of track placement in upper secondary schools. Our analyses show three results. First, upper secondary track placement is consequential for labour market outcomes, even after we control for the selection into tracks on pre-track academic performance and family background characteristics. Second, upper secondary track placement appears to affect labour market outcomes even net of higher education attainment. Third, educational tracking appears to play a role in intergenerational social reproduction net of family background-based skill gaps, suggesting that track choice help maintain inequalities across generations. We discuss the implications of our findings for the literature on educational tracking.
Birth cohorts are essential for developing evidence-based policies and advancing knowledge on different aspects of the concept of developmental origins of health and diseases (DOHaD). The Prospective Epidemiological Research Studies in IrAN (PERSIAN) is a multicentre cohort in Iran. It is one of the pioneers of DOHaD research in the Middle East and North Africa (MENA) region. This profile provides a brief overview of this birth cohort, focusing on the objectives and design of the study. The main objective of this birth cohort is to evaluate the associations of socio-economic characteristics, lifestyle, diet, environmental exposures and epigenetic factors with outcomes of: pregnancy; mother and child mental and physical health and well-being; child neurodevelopment; and the establishment of chronic disease risk factors.
The enrolment of PERSIAN Birth Cohort participants is currently ongoing in five Iranian cities (Isfahan, Yazd, Semnan, Sari and Rafsanjan). We plan to recruit 15,000 mother–offspring pairs, and to follow them for at least ten years. Data collection consists of three consecutive phases: (1) periconception until birth; (2) infancy (0–2 years); and (3) childhood (3–11 years). We are collecting data on both ‘determinants of health’ and ‘health outcomes’. In addition to questionnaires and physical examination, various biological samples, including blood, urine, hair, nail, cord blood and breastmilk are being collected. Growth and neurodevelopment of children will be monitored. Appropriate data analysis schemes will be employed to assess the role of early life factors in health and disease that would facilitate international comparisons.
This article brings together methodological insight from two policy-focused studies centrally concerned with understanding experiences of, and responses to, rapidly expanding welfare conditionality (that is, making claimants’ eligibility to social welfare rights dependent on engagement with mandatory behavioural responsibilities under threat of sanction for non-compliance), in the UK context. Qualitative longitudinal approaches are ideally suited to seeking a better understanding of the efficacy and consequences of welfare conditionality and enabling an exploration of how the policy assumptions underpinning this approach intersect with (and often contradict) lived experiences. In this article, we detail the approaches we have taken in employing qualitative longitudinal methodologies and explore the similarities and distinctive features of two policy studies with which the authors were involved (; ). Drawing on data from our two studies, we highlight how a focus on time can deepen our understanding of policy changes and their impact on people’s past, present and future lives. We consider the difference in scale of the two studies and the respective possibilities and challenges in working with quite small and very large sample sizes, including the analytical challenge particular to qualitative longitudinal research. Further, we highlight the value of qualitative longitudinal methods for research that seeks to comprehend the varied effects of welfare conditionality on the lives and behaviour of social security benefit recipients over time. Finally, we reflect on the merits of qualitative longitudinal studies for social policy research more broadly.
Mainstream life course studies often draw on a conventional understanding of time as a unidirectional clock-based entity, which proceeds in a uniform and linear manner. This paper argues that, in order to understand the social, relational and psychological processes of change and continuity that characterise life course processes, we need to adopt a more comprehensive and explicit conceptualisation of time – a conceptualisation that goes beyond an absolute (linear, chronological, uniform) definition – to incorporate the notion of relative time. Drawing on insights from narrative and biographical research, discussions of the temporal embeddedness of human agency and multidisciplinary research on time perceptions and time perspectives, we propose a definition of relative time based on three main characteristics: its multidirectional, elastic and telescopic nature. The paper promotes the integration of absolute and relative time in the study of life course processes, and the important role of prospective qualitative research in this respect, and outlines future avenues for research in this direction.
Childhood maltreatment types (neglect and psychological, physical or sexual abuse) are associated with many poor outcomes in adulthood. Yet, research mainly focuses on the cumulative adversity burden rather than specificities and commonalities of associations with adult outcomes and intervening pathways. This overview therefore summarises evidence from several research studies using the 1958 British Birth Cohort on specific maltreatment types, child development trajectories, adult intermediaries and outcomes. About one in five participants were identified as neglected or abused in childhood. Neglect was associated with key dimensions of development: slower height growth, delayed maturation, faster BMI gain, and poorer emotional and cognitive development. Associated adulthood outcomes included harmful behaviours (notably smoking), poorer physical health (shorter height, excess BMI, poorer blood lipids and glucose, poor-rated health and physical functioning), worse mental health, lower socio-economic circumstances (e.g. poorer living conditions) and elevated mortality in mid-adulthood. Childhood abuse associations were less widespread and were often only for specific types: most were unrelated to childhood height and cognitive abilities, but all were associated with poorer child emotional development, adult mental health, smoking, blood lipids and self-rated health. Additionally, physical abuse was associated with faster BMI gain, higher adult BMI, blood glucose, inflammation and mortality in mid-adulthood; sexual abuse with faster BMI gain, higher adult BMI, poor physical functioning at 50y and higher mortality in mid-adulthood. Adult health measures associated with child maltreatment are key predictors of serious disease, disability and death. Therefore, child maltreatment associations with these measures represent an important burden for individuals and society.
Comparisons between cohort studies and nationally representative ‘real-world’ samples are limited. The NCDS (1958 British birth cohort) follows those born in Britain in a single week in March 1958 (n=18,558); and the ONS Longitudinal Study (LS) contains linked census data and life events for a 1% sample of the population of England and Wales (> 1 million records; allowing for sub-samples by age, ethnicity, or other socio-demographic factors). Common country-and age-matched socio-demographic variables were extracted from the closest corresponding time-points, NCDS 55-year survey in 2013 (n=8107) and LS respondents aged 55 in 2011 (n=7052). Longitudinal associations between socio-demographic exposures (from the NCDS 46-survey in 2004 and LS respondents aged 45 in 2001) and long-term limiting illness (from NCDS 2013 and LS respondents 2011, aged 55) were assessed using logistic regression. The NCDS 55-year sample had similar characteristics to LS respondents aged 55 for sex and marital status, but the NCDS sample had lower levels of long-term limiting illness (19.7% vs 22.8%), non-white ethnicity (2.1% vs 11.7%) and living in South England (46.9% vs 50.1%), and higher levels of full-time employment (61.2% vs 55.2%), working in professional/higher managerial occupations (35.7% vs 29.2%), and living with a spouse (69.1% vs 64.9%), all p<0.001. Nevertheless, longitudinal associations between socio-demographic exposures and long-term limiting illness were similar in the NCDS and LS samples (all tests of between-study heterogeneity in mutually adjusted models p>0.09) suggesting these NCDS findings are largely generalisable to the population of England and Wales.