Educational inequalities in the impact of chronic diseases on exit from paid employment among older workers: A 7-year prospective study in the Netherlands

Objectives: The study aimed to investigate the relative and absolute risks of early exit from paid employment among older workers with a chronic disease, and to assess whether these risks differ across educational groups. Methods: Data on chronic diseases and demographics from 9160 Dutch workers aged 45-64 years were enriched with monthly information on employment status from Statistics Netherlands. Subdistribution hazard ratios (SHR) and 7-year probabilities among workers with a chronic disease of exit from paid employment through disability benefits, unemployment benefits, early retirement benefits or economic inactivity were estimated using competing risks regression analyses based on Fine and Gray's models. Results: Workers with one chronic disease had a higher r

Effects of changes in early retirement policies on labor force participation: the differential effects for vulnerable groups

Objectives This study investigated the effects of a national early retirement reform, which was implemented in 2006 and penalized early retirement, on paid employment and different exit pathways and examined whether these effects differ by gender, income level and health status. Methods This study included all Dutch individuals in paid employment born six months before (control group) and six months after (intervention group) the cut-off date of the reform (1 January 1950) that fiscally penalized early retirement. A regression discontinuity design combined with restricted mean survival time analysis was applied to evaluate the effect of penalizing early retirement on labor force participation from age 60 until workers reached the retirement age of 65 years, while accounting for secular trends around the threshold. Results The intervention grou

Socio-economic inequalities in the effectiveness of workplace health promotion programmes on body mass index: An individual participant data meta-analysis

This individual participant data meta-analysis assessed the effectiveness of workplace health promotion programmes on body mass index (BMI) across socio-economic groups and whether study and intervention characteristics explained inequalities in effectiveness. Studies were eligible if they assessed the effect of a workplace health promotion programme on BMI in the Netherlands, included workers of at least two different socio-economic positions (SEPs) and had a study design with premeasurement and postmeasurement and control condition. Data of 13 studies presenting 16 interventions (5183 participants) were harmonized. In a two-stage meta-analysis, the interaction between intervention and SEP on BMI was tested with linear mixed models for each study. Subsequently, the interaction terms were pooled. The influence of study and intervention characteristics on the effectiveness of workplace health promotion programmes was evaluated using meta-regression analyses. Compared with control conditions, workplace health promotion programmes overall showed a statistically non-significant 0.12 kg/m2 (95% CI: −0.01, 0.25) decrease in BMI, which did not differ across SEP. Interventions evaluated within randomized controlled trials, agentic interventions, those that focused on high-risk groups, included a counselling component, consisted of more than five sessions, or were offered at the individual level did statistically significantly reduce BMI. No evidence was found for intervention-generated SEP inequalities

Influence of chronic diseases on societal participation in paid work, volunteering and informal caregiving in Europe: A 12-year follow-up study

Background: This study aims to provide insight into (1) the associations between having a chronic disease and participation in paid work, volunteer activities or informal care, (2) the associations between the onset of a chronic disease and these forms of societal participation, and (3) whether these associations differ across educational level and gender. Methods: The study population consisted of n=21 875 respondents of the Survey of Health, Ageing and Retirement in Europe aged between 50 years and the country-specific retirement age. The influence of having and the onset of a chronic disease on societal participation was analysed using a hybrid Poisson regression model, combining fixed and random effects, and presented by relative risks (RRs). Results: Individuals with a chronic disease were less likely to participate in paid work (RR: 0.69; 95% CI 0.67 to 0.71) and volunteer activities (RR: 0.92; 95% CI 0.88 to 0.97), but more likely to give informal care (RR: 1.05; 95% CI 1.01 to 1.08). Onset of a chronic disease was associated with a higher likelihood to quit paid work (RR: 0.91; 95% CI 0.86 to 0.97) and to give informal care (RR: 1.08; 95% CI 1.01 to 1.16). Lower educated individuals with a chronic disease or with the onset of a chronic disease were less likely to have paid work than higher educated individuals. Conclusion: Individuals with a chronic disease were less likely to participate in paid work and volunteer activities, and more likely to provide informal care. Educational inequalities were present for paid work. More insight into which factors hinder societal participation among individuals with a chronic disease is needed

The role of personal characteristics, work environment and context in working beyond retirement: a mixed-methods study

Objective: To investigate the role of personal characteristics, work environment and context in working beyond retirement. Methods: In the current study, a mixed-methods design was applied including quantitative survey data and semi-structured telephone interviews. Respondents (N = 568) were selected from the Study on Transitions in Employment, Ability and Motivation (STREAM). Personal characteristics, work characteristics and contextual factors were measured using a questionnaire at baseline. Concurrently, qualitative data of 30 persons aged over 65 years were gathered. Logistic regression analyses were used to identify quantitative associations and thematic analyses were used for qualitative purposes. Results: Quantitative data revealed that being in good physical health (OR = 1.80), developmental proactivity (OR = 1.38), interesting work (OR = 2.02), appreciation (OR = 1.62) and voluntary work (OR = 1.58) were associated with working beyond the statutory retirement age. Additionally, qualitative findings suggested that working beyond retirement was mainly driven by the desire to contribute to society (e.g., mentor younger co

Evaluation of occupational health interventions using a randomized controlled trial: Challenges and alternative research designs

Occupational health researchers regularly conduct evaluative intervention research for which a randomized controlled trial (RCT) may not be the most appropriate design (eg, effects of policy measures, organizational interventions on work schedules). This article demonstrates the appropriateness of alternative designs for the evaluation of occupational health interventions, which permit causal inferences, formulated along two study design approaches: experimental (stepped-wedge) and observational (propensity scores, instrumental variables, multiple baseline design, interrupted time series, difference-in-difference, and regression discontinuity). For each design, the unique characteristics are presented including the advantages and disadvantages compared to the RCT, illustrated by empirical examples in occupational health. This overview shows that several appropriate alternatives for the RCT design are feasible and available, which may provide sufficiently strong evidence to guide decisions on implementation of interventions in workplaces. Researchers are encouraged to continue exploring these designs and thus contribute to evidence-based occupational health

Chitinases and arabinogalactan proteins in somatic embryogenesis

In vitro cultured carrot suspension cells can function as starting material for the generation of somatic embryos. Compounds secreted by suspension cells can influence the process of somatic embryogenesis. One class of such compounds, the secreted EP3 endochitinases, was found to lift the developmental arrest of somatic embryos formed in the temperature sensitive carrot cell line ts11 , when cultured at restrictive temperatures. In addition, this chitinase was able to increase the number of ts11 somatic embryos as observed at the restrictive temperatures. The bacterial lipochitooligosaccharide (LCO) NodRlv-V(Ac, C18:4) was able to mimick the effects of EP3 endochitinases on ts11 somatic embryogenesis. The major goal of the study presented in this thesis was to identify plant produced compounds that contain an endochitinase cleavage site. Such compounds could then lead to the discovery of possible plant LCO analogues.In Chapter 1 an introduction concerning the roles and effects of compounds that influence embryogenesis is given. Besides a description of zygotic and somatic embryogenesis, this overview presents a number of classical and non-classical growth regulators that function in embryogenesis. It is discussed what role carbohydrates and proteoglycans can play in the initiation of embryogenesis.In Chapter 2 experiments are presented that identify suspension cells and plant tissues expressing EP3 endochitinase genes. In addition, the localisation of EP3 proteins in suspension cells and in seeds was determined. EP3 genes were only expressed in cells that were in the vicinity of zygotic or somatic embryos, but not in embryos themselves. The localisation of the secreted EP3 enzymes in the culture medium and in the endosperm suggested a "nursing" function for EP3 endochitinases during embryogenesis.In Chapter 3 the production of catalytically active carrot and Arabidopsis EP3 endochitinases in insect cells infected with recombinant baculoviruses is reported. Characterization of individual carrot EP3 endochitinase isozymes showed that all baculovirus produced carrot chitinases are able to cleave chitin as well as chitosan. Furthermore, the occurrence of the Arabidopsis chitinase AtEP3 in the medium of embryogenic Arabidopsis suspension cultures and its absence in non-embryogenic cultures identified AtEP3 as a good marker for the capability of such cultures to form somatic embryos.In Chapter 4 evidence is presented for the occurrence of N-acetylglucosamine (GlcNAc) in arabinogalactan proteins (AGPs) present in the medium of carrot embryogenic suspension cultures. AGPs isolated from immature carrot seeds, were found to contain endochitinase cleavage sites. The identification of these cleavage sites and the differences in the total population of AGPs isolated from carrot seeds at different stages of seed development suggested a substantial amount of processing of AGPs in carrot seeds.In Chapter 5 experiments are described that demonstrate that both EP3 endochitinases as well as AGPs can promote the formation of protoplast derived wild type somatic embryos. Pre-treatment of immature seed AGPs with chitinases before addition to carrot protoplasts was shown to increase the embryo-promoting effect.In chapter 6 the role of GlcNAc containing molecules in plant and animal development is discussed, with a special emphasis on the role of GlcNAc containing AGPs as the natural substrate for endochitinases in plant embryogenesis

A relationship between seed development, Arabinogalactan-proteins (AGPs) and the AGP mediated promotion of somatic embryogenesis

Arabinogalactan-protein (AGP) epitopes are known to display developmentally regulated patterns of expression in several plant tissues. Therefore, AGPs have been suggested to play a role in plant development. Somatic embryogenesis is regulated by AGPs as well as by EP3 endochitinases. Using four different methods we have analysed the composition of AGPs in immature carrot seeds. The results obtained show that: (1) the native electrophoretic mobility of such AGPs changes during development; (2) AGP epitopes in immature seeds are developmentally regulated; (3) enzymatically released fragments of AGPs show that the composition of these molecules changes as a function of development; and (4) the biological activity of AGPs on the formation of somatic embryos changes depending on the age of the seeds. Our results suggest that degradation of maternally derived AGPs occurs after fertilization, while cellularization of the endosperm leads to synthesis of a new set of AGPs. The presence of an endochitinase cleavage site as well as the capacity to increase somatic embryogenesis only occurred in AGPs that were isolated from seeds in which the endosperm had been cellularized. Apparently, both EP3 endochitinases and somatic embryogenesis-promoting AGPs are developmentally regulated in immature carrot seeds