Socioeconomic indicators in epidemiologic research: A practical example from the LIFEPATH study

Contextual and individual inequalities in breast cancer screening participation and outcomes in Turin (North-West Italy)

Breast cancer incidence and screening participation exhibit an unequal distribution in the population. This study aims to investigate the impact of socioeconomic position (SEP) on three breast screening indicators (participation, recall, and cancer detection rates) among women aged 50-69 in the city of Turin between 2010 and 2019. The study also aims to determine whether contextual factors (deprivation index) or individual factors (educational level) have a greater influence. The data used in this study are sourced from the Turin Breast Screening Program (TBSP) and the Turin Longitudinal Study (TLS). To test the hypothesis and account for the hierarchical structure of the data, multilevel models were used. Both contextual and individual SEP were found to be associated with screening participation. Participation increased with higher levels of deprivation (odds ratio for most deprived: 1.13; 95% CI 1.11-1.16) and decreased with higher educational levels (OR for low educated: 1.37; 95% CI 1.34-1.40). Contextual SEP did not show any association with recall or cancer detection rates, but individual SEP had an impact. Women with lower educational levels had a statistically significant 19% lower odds of being recalled and a statistically significant 20% lower odds of being diagnosed with cancer. Additionally, immigrant women were less likely to participate in screening, be recalled, or receive a cancer diagnosis. Educational level consistently influenced the analyzed screening indicators, while contextual deprivation appeared to have less importance. It is likely that women living in less deprived areas and with higher education have greater access to opportunistic screening.

Theories, determinants, and intervention models and approaches on inequalities of undernutrition amongst under fives: A literature review

Background and Aims

One of the greatest public health problems of the 21st century is undernutrition in children under the age of 5 years (CAUFY). Globally, over 232 million CUAFY are undernourished and approximately 45% of mortality in this population are undernutrition-induced. This paper reviewed and critically explained the factors perpetuating undernutrition in CUAFY in the global space. It further explained the multi-level determinants that influence health inequalities and consequently exacerbate undernutrition amongst CUAFY globally. It also went further to explain the intervention models and approaches that can be used to tackle undernutrition in CUAFY.

Methods/Literature Search Strategy

Demiris et al.'s approach to narrative review was utilized for this paper. Relevant articles on child nutrition were retrieved from multiple credible databases and websites of foremost health organizations. Using an iterative process, multiple combinations of search terms were done by stringing relevant key terms and their synonyms with Boolean Operators. This process was constantly refined to align search results with the study aim. Database search produced relevant and resourceful publications which were utilized to develop this review.

Results

The global burden of undernutrition remains high, especially in Oceania with the highest prevalence of stunting and wasting (41.4% and 12.5%), with Africa and Asia following closely. Malnutrition eradication is a global health issue of high priority as demonstrated by the "Goal 2" of the Sustainable Development Goals (SDGs), and the United Nations (UN) Decade of Action on Nutrition 2016-2025. The review identified no significant positive outcome from previous interventions due to the endemic health inequalities. Determinants of the multi-level health inequalities associated with undernutrition in CUAFY, and probable solutions are explained with theoretical models of health inequalities. A diagonal intervention approach was proposed as a viable solution to ending undernutrition in CUAFY.

Conclusion

The application of relevant theoretical models and context-specific intervention approaches can be utilized by stakeholders to close the existing inequality gaps, thereby reducing undernutrition amongst CUAFY globally.

Trends in social inequality in mortality in Denmark 1995-2019: the contribution of smoking- and alcohol-related deaths

BACKGROUND

During the past decades, social inequality in mortality has increased in several countries, including Denmark. Modifiable risk factors, such as smoking and harmful alcohol consumption, have been suggested to moderate the association between socioeconomic position and health-related outcomes. The present study aims to investigate the contribution of smoking- and alcohol-related deaths to the trends in educational inequality in mortality in Denmark 1995-2019 among individuals aged 30-74 years.

METHODS

Nationwide data on mortality and highest attained educational level divided into quartiles were derived from administrative registers. Alcohol-related mortality was directly estimated using information on alcohol-related deaths from death certificates. Smoking-related mortality was indirectly estimated using the Peto-Lopez method. The contribution of smoking- and alcohol-related deaths to the social inequality gap in mortality 1995-2019 was calculated.

RESULTS

Alongside a decrease in all-cause mortality in Denmark 1995-2019, absolute differences in the mortality rate (per 100 000 person-year) between the lowest and the highest educational quartile increased from 494 to 607 among men and from 268 to 376 among women. Among both men and women, smoking- and alcohol-related deaths explained around 60% of the social inequality in mortality and around 50% of the increase in mortality inequality.

CONCLUSION

Smoking and harmful alcohol consumption continue to be important risk factors and causes of social inequality in mortality, with around half of the increase in Denmark 1995-2019 being attributable to smoking- and alcohol-related deaths. Future healthcare planning and policy development should aim at reducing social inequality in modifiable health risk behaviours and their negative consequences.

Bayesian multilevel modelling of the association between socio-economic status and stunting among under-five-year children in Tanzania

BACKGROUND

Stunting is associated with socioeconomic status (SES) which is multidimensional. This study aimed to compare different SES indices in predicting stunting.

METHODS

This was the secondary data analysis using Tanzania Demographics and Health Surveys (TDHS). The study used 7492, 6668, and 8790 under-five-year children from TDHS 2004/5, 2010, and 2015/16, respectively. The Household Wealth Index (HWI); Water and Sanitation, Assets, Maternal education and Income (WAMI); Wealth Assets, Education, and Occupation (WEO); and the Multidimensional Poverty Index (MPI) indices were compared. The summated scores, principal component analysis (PCA), and random forest (RF) approaches were used to construct indices. The Bayesian and maximum likelihood multilevel generalized linear mixed models (MGLMM) were constructed to determine the association between each SES index and stunting.

RESULTS

The study revealed that 42.3%, 38.4%, and 32.4% of the studied under-five-year children were stunted in 2004/5, 2010, and 2015/16, respectively. Compared to other indicators of SES, the MPI had a better prediction of stunting for the TDHS 2004/5 and 2015/16, while the WAMI had a better prediction in 2010. For each score increase in WAMI, the odds of stunting were 64% [BPOR = 0.36; 95% CCI 0.3, 0.4] lower in 2010, while for each score increase in MPI there was 1 [BPOR = 1.1; 95% CCI 1.1, 1.2] times higher odds of stunting in 2015/16.

CONCLUSION

The MPI and WAMI under PCA were the best measures of SES that predict stunting. Because MPI was the best predictor of stunting for two surveys (TDHS 2004/5 and 2015/16), studies dealing with stunting should use MPI as a proxy measure of SES. Use of BE-MGLMM in modelling stunting is encouraged. Strengthened availability of items forming MPI is inevitable for child growth potentials. Further studies should investigate the determinants of stunting using Bayesian spatial models to take into account spatial heterogeneity.

The potential of intervening on childhood adversity to reduce socioeconomic inequities in body mass index and inflammation among Australian and UK children: A causal mediation analysis

BACKGROUND

Lower maternal education is associated with higher body mass index (BMI) and higher chronic inflammation in offspring. Childhood adversity potentially mediates these associations. We examined the extent to which addressing childhood adversity could reduce socioeconomic inequities in these outcomes.

METHODS

We analysed data from two early-life longitudinal cohorts: the Longitudinal Study of Australian Children (LSAC; n=1873) and the UK Avon Longitudinal Study of Parents and Children (ALSPAC; n=7085).

EXPOSURE

low/medium (below university degree) versus high maternal education, as a key indicator of family socioeconomic position (0-1 year).

OUTCOMES

BMI and log-transformed glycoprotein acetyls (GlycA) (LSAC: 11-12 years; ALSPAC: 15.5 years). Mediator: multiple adversities (≥2/<2) indicated by family violence, mental illness, substance abuse and harsh parenting (LSAC: 2-11 years; ALSPAC: 1-12 years). A causal mediation analysis was conducted.

RESULTS

Low/medium maternal education was associated with up to 1.03 kg/m2 higher BMI (95% CI: 0.95 to 1.10) and up to 1.69% higher GlycA (95% CI: 1.68 to 1.71) compared with high maternal education, adjusting for confounders. Causal mediation analysis estimated that decreasing the levels of multiple adversities in children with low/medium maternal education to be like their high maternal education peers could reduce BMI inequalities by up to 1.8% and up to 3.3% in GlycA.

CONCLUSIONS

Our findings in both cohorts suggest that slight reductions in socioeconomic inequities in children's BMI and inflammation could be achieved by addressing childhood adversities. Public health and social policy efforts should help those affected by childhood adversity, but also consider underlying socioeconomic conditions that drive health inequities.

The FLY-project: study protocol for mixed methods research to explore the complex social dynamics of sustainable food-related lifestyles in youth in practical education

BACKGROUND

The present-day food system is a key driver of climate change and biodiversity loss, making it imperative for populations to shift towards more sustainable diets. The involvement of youth in this transition is vital because they are in a formative period where their identities, values, and norms, including their food behaviours, are being shaped. Special attention should be paid to youth in practical education because they are often overlooked in existing studies, yet evidence suggests they may lack the necessary resources to support dietary changes, resulting in lower levels of pro-environmental food-related behaviours. The aim of the FLY (Food-related Lifestyles in Youth) project is to study how sustainable food-related lifestyles and underlying factors develop in early adolescence, particularly in Dutch youth in practical education, how these spread in social networks, and to develop community-level intervention strategies to support youths' transition to sustainable food-related behaviours.

METHODS/DESIGN

The FLY-project adopts a mixed-method approach. First, two literature reviews are conducted. A systematic review assesses how capabilities, opportunities and motivation are associated with sustainable food behaviours in youth, and how these elements interrelate in determining sustainable food-related lifestyles. A scoping review studies community-level interventions that target sustainable and healthy food-related behaviours. Second, focus groups are conducted to explore the barriers and facilitating factors concerning capabilities, opportunities, and motivations that Dutch youth in practical-level education experience to transition to more sustainable food-related lifestyles. Third, a cohort survey study is conducted to track the dynamic interplay between capabilities, opportunities, motivation, and changes in specific sustainable food behaviours over time, and to assess the diffusion of sustainable food-related lifestyles via social (media) networks. Fourth, an experimental research programme tests promising intervention approaches, some of which are co-created with youth, targeting relevant underlying factors.

DISCUSSION

This paper describes the rationale, conceptual framework, design and methods of the FLY-project. The FLY-project contributes to an understanding of underlying factors of sustainable food-related behaviours in adolescence and results in a multi-component intervention toolkit, with a particular focus on youth in practical education programmes.

Socioeconomic changes predict genome-wide DNA methylation in childhood

Childhood socioeconomic position (SEP) is a major determinant of health and well-being across the entire life course. To effectively prevent and reduce health risks related to SEP, it is critical to better understand when and under what circumstances socioeconomic adversity shapes biological processes. DNA methylation (DNAm) is one such mechanism for how early life adversity 'gets under the skin'. In this study, we evaluated the dynamic relationship between SEP and DNAm across childhood using data from 946 mother-child pairs in the Avon Longitudinal Study of Parents and Children. We assessed six SEP indicators spanning financial, occupational and residential domains during very early childhood (ages 0-2), early childhood (ages 3-5) and middle childhood (ages 6-7). Epigenome-wide DNAm was measured at 412 956 cytosine-guanines (CpGs) from peripheral blood at age 7. Using an innovative two-stage structured life-course modeling approach, we tested three life-course hypotheses for how SEP shapes DNAm profiles-accumulation, sensitive period and mobility. We showed that changes in the socioeconomic environment were associated with the greatest differences in DNAm, and that middle childhood may be a potential sensitive period when socioeconomic instability is especially important in shaping DNAm. Top SEP-related DNAm CpGs were overrepresented in genes involved in pathways important for neural development, immune function and metabolic processes. Our findings highlight the importance of socioeconomic stability during childhood and if replicated, may emphasize the need for public programs to help children and families experiencing socioeconomic instability and other forms of socioeconomic adversity.

Mediating Role of Lifestyle Behaviors in the Association between Education and Cancer: Results from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Many studies have shown that socioeconomic position (SEP) is associated with the incidence of malignant tumors at different sites. This study aims to estimate the association between educational level (as proxy for SEP) and cancer incidence and to understand whether the observed associations might be partially explained by lifestyle behaviors.

METHODS

The analyses were performed on data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, globally and by sex. We used Cox proportional hazards models together with mediation analysis to disentangle the total effect (TE) of educational level [measured through the Relative Index of Inequality (RII)] on cancer incidence into pure direct (PDE) and total indirect (TIE) effect, unexplained and explained by mediators, respectively. PDE and TIE were then combined to compute the proportions mediated (PM).

RESULTS

After an average of 14 years of follow-up, 52,422 malignant tumors were ascertained. Low educated participants showed higher risk of developing stomach, lung, kidney (in women), and bladder (in men) cancers, and, conversely, lower risk of melanoma and breast cancer (in post-menopausal women), when compared with more educated participants. Mediation analyses showed that portions of the TE of RII on cancer could be explained by site-specific related lifestyle behaviors for stomach, lung, and breast (in women).

CONCLUSIONS

Cancer incidence in Europe is determined at least in part by a socioeconomically stratified distribution of risk factors.

IMPACT

These observational findings support policies to reduce cancer occurrence by altering mediators, such as lifestyle behaviors, particularly focusing on underprivileged strata of the population.

Determining the spatial distribution of environmental and socio-economic suitability for human leptospirosis in the face of limited epidemiological data

Background

Leptospirosis is among the leading zoonotic causes of morbidity and mortality worldwide. Knowledge about spatial patterns of diseases and their underlying processes have the potential to guide intervention efforts. However, leptospirosis is often an underreported and misdiagnosed disease and consequently, spatial patterns of the disease remain unclear. In the absence of accurate epidemiological data in the urban agglomeration of Santa Fe, we used a knowledge-based index and cluster analysis to identify spatial patterns of environmental and socioeconomic suitability for the disease and potential underlying processes that shape them.

Methods

We geocoded human leptospirosis cases derived from the Argentinian surveillance system during the period 2010 to 2019. Environmental and socioeconomic databases were obtained from satellite images and publicly available platforms on the web. Two sets of human leptospirosis determinants were considered according to the level of their support by the literature and expert knowledge. We used the Zonation algorithm to build a knowledge-based index and a clustering approach to identify distinct potential sets of determinants. Spatial similarity and correlations between index, clusters, and incidence rates were evaluated.

Results

We were able to geocode 56.36% of the human leptospirosis cases reported in the national epidemiological database. The knowledge-based index showed the suitability for human leptospirosis in the UA Santa Fe increased from downtown areas of the largest cities towards peri-urban and suburban areas. Cluster analysis revealed downtown areas were characterized by higher levels of socioeconomic conditions. Peri-urban and suburban areas encompassed two clusters which differed in terms of environmental determinants. The highest incidence rates overlapped areas with the highest suitability scores, the strength of association was low though (CSc r = 0.21, P < 0.001 and ESc r = 0.19, P < 0.001).

Conclusions

We present a method to analyze the environmental and socioeconomic suitability for human leptospirosis based on literature and expert knowledge. The methodology can be thought as an evolutive and perfectible scheme as more studies are performed in the area and novel information regarding determinants of the disease become available. Our approach can be a valuable tool for decision-makers since it can serve as a baseline to plan intervention measures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40249-022-01010-x.

Durability of the Treatment Effects of an 8-Week Self-administered Home-Based Virtual Reality Program for Chronic Low Back Pain: Follow-up Study of a Randomized Clinical Trial

Background

We previously reported the efficacy of an 8-week home-based therapeutic immersive virtual reality (VR) program in a double-blind randomized placebo-controlled study. Community-based adults with self-reported chronic low back pain were randomized 1:1 to receive either (1) a 56-day immersive therapeutic pain relief skills VR program (EaseVRx) or (2) a 56-day sham VR program. Immediate posttreatment results revealed the superiority of therapeutic VR over sham VR for reducing pain intensity; pain-related interference with activity, mood, and stress (but not sleep); physical function; and sleep disturbance. At 3 months posttreatment, therapeutic VR maintained superiority for reducing pain intensity and pain-related interference with activity, stress, and sleep (new finding).

Objective

This study assessed between-group and within-group treatment effects 6 months posttreatment to determine the extended efficacy, magnitude of efficacy, and clinical importance of home-based therapeutic VR.

Methods

E-surveys were deployed at pretreatment, end-of-treatment, and posttreatment months 1, 2, 3, and 6. Self-reported data for 188 participants were analyzed in a mixed-model framework using a marginal model to allow for correlated responses across the repeated measures. Primary outcomes were pain intensity and pain-related interference with activity, mood, stress, and sleep at 6 months posttreatment. Secondary outcomes were Patient-Reported Outcome Measurement Information System (PROMIS) sleep disturbance and physical function.

Results

Therapeutic VR maintained significant and clinically meaningful effects 6 months posttreatment and remained superior to sham VR for reducing pain intensity and pain-related interference with activity, stress, and sleep (d_s=0.44-0.54; P<.003). Between-group comparisons for physical function and sleep disturbance showed superiority of EaseVRx over sham VR (d_s=0.34; P=.02 and d_s=0.46; P<.001, respectively). Participants were encouraged to contact study staff with any problems experienced during treatment; however, no participants contacted study staff to report adverse events of any type, including nausea and motion sickness.

Conclusions

Our 8-week home-based VR pain management program caused important reductions in pain intensity and interference up to 6 months after treatment. Additional studies are needed in diverse samples.

Trial Registration

ClinicalTrials.gov NCT04415177; https://clinicaltrials.gov/ct2/show/NCT04415177

International Registered Report Identifier (IRRID)

RR2-10.2196/25291

Increasing prevalence of chronic non-cancer pain in Denmark from 2000 to 2017: A population-based survey

BACKGROUND

This investigation comprised information from the Danish population to analyse the development of chronic non-cancer pain (CNCP) prevalence according to sex, age, physical job demand and educational level.

METHODS

Data derives from the Danish Health and Morbidity Surveys based on random samples of adults living in Denmark. The analysed samples were composed by 10,457 in 2000 (response rate: 62.7%), 5686 in 2005 (52.1%), 15,165 in 2010 (60.1%), 14,265 in 2013 (57.1%) and 14,022 in 2017 (56.1%). CNCP was defined as pain lasting 6 months or more. Individuals with a self-reported history of cancer were excluded. Calibration weighting was applied to reduce the impact of potential non-response bias. The Relative and the Absolute Concentration Index were calculated to measure educational inequalities.

RESULTS

CNCP prevalence has increased 8.3 percentage points during 2000-2017 (19.5%-27.8%) and is highest among women (22.1% to 30.8%). Higher CNCP prevalence among men aged 45-64 years exceeded the men aged >65 years in 2017 (31.9% and 29.8%, respectively). There was a continuous increase in CNCP prevalence in individuals with sedentary work or low physical demand at job from 2000 to 2017; among those with moderate or high physical demand at job the prevalence increased sharply from 2000 to 2010 after which the prevalence remained stable. Higher CNCP prevalence persisted among individuals with lower level of education regardless of gender and the inequalities remained stable over time.

CONCLUSION

The Danish prevalence of chronic pain has increased in the last two decades and higher numbers are observed in some sociodemographic groups.

SIGNIFICANCE

This study provides an overview of the development of chronic non-cancer pain in a country and analyses the trends with socioeconomic inequalities. The continuous increasing prevalence may have huge social and economic implications. This study reveals an urgent need for measures to attenuate the increasing prevalence, which should be a priority for public health policy.

Swedish snus use is associated with mortality: a pooled analysis of eight prospective studies

BACKGROUND

The health consequences of the use of Swedish snus, including its relationship with mortality, have not been fully established. We investigated the relationship between snus use and all-cause and cause-specific mortality (death due to cardiovascular diseases, cancer diseases and all other reasons, respectively) in a nationwide collaborative pooling project.

METHODS

We followed 169 103 never-smoking men from eight Swedish cohort studies, recruited in 1978-2010. Shared frailty models with random effects at the study level were used in order to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of mortality associated with snus use.

RESULTS

Exclusive current snus users had an increased risk of all-cause mortality (aHR 1.28, 95% CI 1.20-1.35), cardiovascular mortality (aHR 1.27, 95% CI 1.15-1.41) and other cause mortality (aHR 1.37, 95% CI 1.24-1.52) compared with never-users of tobacco. The risk of cancer mortality was also increased (aHR 1.12, 95% CI 1.00-1.26). These mortality risks increased with duration of snus use, but not with weekly amount.

CONCLUSIONS

Snus use among men is associated with increased all-cause mortality, cardiovascular mortality, with death from other causes and possibly with increased cancer mortality.

Multivariate genome-wide analysis of education, socioeconomic status and brain phenome

Socioeconomic status (SES) and education (EDU) are phenotypically associated with psychiatric disorders and behaviours. It remains unclear how these associations influence genetic risk for psychopathology, psychosocial factors and EDU and/or SES (EDU/SES) individually. Using information from >1 million individuals, we conditioned the genetic risk for psychiatric disorders, personality traits, brain imaging phenotypes and externalizing behaviours with genome-wide data for EDU/SES. Accounting for EDU/SES significantly affected the observed heritability of psychiatric traits, ranging from 2.44% h2 decrease for bipolar disorder to 14.2% h2 decrease for Tourette syndrome. Neuroticism h2 significantly increased by 20.23% after conditioning with SES. After EDU/SES conditioning, neuronal cell types were identified for risky behaviour (excitatory), major depression (inhibitory), schizophrenia (excitatory and γ-aminobutyric acid (GABA) mediated) and bipolar disorder (excitatory). Conditioning with EDU/SES also revealed unidirectional causality between brain morphology, psychopathology and psychosocial factors. Our results indicate that genetic discoveries related to psychopathology and psychosocial factors may be limited by genetic overlap with EDU/SES.

Reducing socio-economic inequalities in all-cause mortality: a counterfactual mediation approach

Background

Socio-economic inequalities in mortality are well established, yet the contribution of intermediate risk factors that may underlie these relationships remains unclear. We evaluated the role of multiple modifiable intermediate risk factors underlying socio-economic-associated mortality and quantified the potential impact of reducing early all-cause mortality by hypothetically altering socio-economic risk factors.

Methods

Data were from seven cohort studies participating in the LIFEPATH Consortium (total n = 179 090). Using both socio-economic position (SEP) (based on occupation) and education, we estimated the natural direct effect on all-cause mortality and the natural indirect effect via the joint mediating role of smoking, alcohol intake, dietary patterns, physical activity, body mass index, hypertension, diabetes and coronary artery disease. Hazard ratios (HRs) were estimated, using counterfactual natural effect models under different hypothetical actions of either lower or higher SEP or education.

Results

Lower SEP and education were associated with an increase in all-cause mortality within an average follow-up time of 17.5 years. Mortality was reduced via modelled hypothetical actions of increasing SEP or education. Through higher education, the HR was 0.85 [95% confidence interval (CI) 0.84, 0.86] for women and 0.71 (95% CI 0.70, 0.74) for men, compared with lower education. In addition, 34% and 38% of the effect was jointly mediated for women and men, respectively. The benefits from altering SEP were slightly more modest.

Conclusions

These observational findings support policies to reduce mortality both through improving socio-economic circumstances and increasing education, and by altering intermediaries, such as lifestyle behaviours and morbidities.

The impact of lifecourse socio-economic position and individual social mobility on breast cancer risk

BACKGROUND

Women with an advantaged socioeconomic position (SEP) have a higher risk of developing breast cancer (BC). The reasons for this association do not seem to be limited to reproductive factors and remain to be understood. We aimed to investigate the impact of lifecourse SEP from childhood and social mobility on the risk of BC considering a broad set of potential mediators.

METHODS

We used a discovery-replication strategy in two European prospective cohorts, E3N (N = 83,436) and EPIC-Italy (N = 20,530). In E3N, 7877 women were diagnosed with BC during a median 24.4 years of follow-up, while in EPIC-Italy, 893 BC cases were diagnosed within 15.1 years. Hazard ratios (HR) were estimated using Cox proportional hazard models on imputed data.

RESULTS

In E3N, women with higher education had a higher risk of BC (HR [95%CI] = 1.21 [1.12, 1.30]). This association was attenuated by adjusting for reproductive factors, in particular age at first childbirth (HR[95%CI] = 1.13 [1.04, 1.22]). Health behaviours, anthropometric variables, and BC screening had a weaker effect on the association. Women who remained in a stable advantaged SEP had a higher risk of BC (HR [95%CI] = 1.24 [1.07; 1.43]) attenuated after adjustment for potential mediators (HR [95%CI] = 1.13 [0.98; 1.31]). These results were replicated in EPIC-Italy.

CONCLUSIONS

These results confirm the important role of reproductive factors in the social gradient in BC risk, which does not appear to be fully explained by the large set of potential mediators, including cancer screening, suggesting that further research is needed to identify additional mechanisms.

Lifetime Duration of Exposure to Biomechanical Factors at Work as a Mediator of the Relationship Between Socioeconomic Position and Walking Speed

The study aimed to assess the proportion mediated by the duration of exposure to ergonomic factors at work on the relationship between socioeconomic position (SEP) and low walking speed. This cross-sectional study was performed on data collected at baseline on 19,704 men and 20,273 women 45-70 years old, currently or previously employed, enrolled in the Constances cohort. SEP was assigned through current or last occupation, categorized in three classes, based on the European Socioeconomic Classification. Walking speed was assessed through one measurement of normal walking for 3 m and dichotomized at the lowest quintile of the sex- and age- (5-year) specific distribution. Self-reported workplace exposure throughout working life to repetitive work, intense physical work, and lifting/carrying heavy loads was used to assess the duration of exposure to each factor, categorized in four classes. Through Poisson regression models, adjusted for BMI, smoking, alcohol intake, hypertension, physical activity, diabetes, cardiovascular diseases, and a cognitive score, the attenuation in the prevalence ratio (PR) of low walking speed by SEP produced by the inclusion of duration of exposure to each factor was evaluated. The mediating effect of work ergonomic exposures on the relationship between SEP and low walking speed was assessed using the weighted method by Vanderweele. In the fully adjusted model without ergonomic exposures, both men and women in the middle and the lowest SEP had a significantly increased risk of low walking speed compared with those in the highest SEP (men: PR = 1.30 and PR = 1.46, respectively; women: PR = 1.24 and PR = 1.45, respectively). The inclusion in separate regression models of exposure duration to repetitive work, intense physical work, and handling of heavy loads produced modest risk attenuations in both men and women, all smaller or around 10%. Mediation analysis revealed in both sexes significant mediation effects for most ergonomic exposures considered, although also with low mediation effects. Significant differences in walking speed by SEP were observed in this large sample, but the proportion of such differences explained by the duration of exposure to ergonomic factors at work was low using either the risk attenuation or the mediation analysis methods.

Patterning of educational attainment across inflammatory markers: Findings from a multi-cohort study

BACKGROUND

Evidence suggests that the inflammatory reaction, an adaptive response triggered by a variety of harmful stimuli and conditions involved in the risk and development of many chronic diseases, is a potential pathway through which the socioeconomic environment is biologically embedded. Difficulty in interpreting the role of the inflammatory system in the embodiment dynamic arises because of heterogeneity across studies that use a limited but varied number of inflammatory markers. There is no consensus in the literature as to which inflammatory markers beyond the C-reactive protein and to a lesser extent interleukin 6 are related to the social environment. Accordingly, we aimed to investigate the association between educational attainment, and several markers of inflammation - C-reactive protein, fibrinogen, interleukin 6, interleukin 1β and tumor necrosis factor α- in 6 European cohort studies.

METHODS

Up to 17,470 participants from six European cohort studies with data on educational attainment, health behaviors and lifestyle factors, and at least two different inflammatory markers. Four sub-datasets were drawn with varying numbers of participants to allow pairwise comparison of the social patterning of C-reactive protein and any other inflammatory markers. To evaluate within each sub-dataset the importance of the context and cohort specificities, linear regression-based analyses were performed separately for each cohort and combined in a random effect meta-analysis to determine the relationship between educational attainment and inflammation.

RESULTS

We found that the magnitude of the relationship between educational attainment and five inflammatory biomarkers (C-reactive protein, fibrinogen, interleukin 6 and 1β and tumor necrosis factor α) was variable. By far the most socially patterned biomarker was C-reactive protein, followed by fibrinogen and to lesser extent interleukin 6, where a low educational attainment was associated with higher inflammation even after adjusting for health behaviours and body mass index. No association was found with interleukin 1β and tumor necrosis factor α.

CONCLUSIONS

Our study suggests different educational patterning of inflammatory biomarkers. Further large-scale research is needed to explore social differences in the inflammatory cascade in greater detail and the extent to which these differences contribute to social inequalities in health.

Adherence to the Mediterranean diet partially mediates socioeconomic differences in leukocyte LINE-1 methylation: evidence from a cross-sectional study in Italian women

Although previous research demonstrated that socioeconomic status (SES) might affect DNA methylation, social inequalities alone do not completely explain this relationship. We conducted a cross-sectional study on 349 women (Catania, Italy) to investigate whether behaviors might mediate the association between SES and long interspersed nuclear elements (LINE-1) methylation, a surrogate marker of global DNA methylation. Educational level, used as an indicator of SES, and data on behaviors (i.e. diet, smoking habits, physical activity, and weight status) were collected using structured questionnaires. Adherence to Mediterranean diet (MD) was assessed by the Mediterranean Diet Score (MDS). Leukocyte LINE-1 methylation was assessed by pyrosequencing. Mediation analysis was conducted using the procedure described by Preacher and Hayes. Women with high educational level exhibited higher MDS (β = 0.669; 95%CI 0.173-1.165; p < 0.01) and LINE-1 methylation level (β = 0.033; 95%CI 0.022-0.043; p < 0.001) than their less educated counterpart. In line with this, mediation analysis demonstrated a significant indirect effect of high educational level on LINE-1 methylation through the adherence to MD (β = 0.003; 95%CI 0.001-0.006). Specifically, the mediator could account for 9.5% of the total effect. To our knowledge, this is the first study demonstrating the mediating effect of diet in the relationship between SES and DNA methylation. Although these findings should be confirmed by prospective research, they add value to the promotion of healthy dietary habits in social disadvantaged people.

The contribution of sleep to social inequalities in cardiovascular disorders: a multi-cohort study

AIMS

Sleep disturbances exhibit a strong social patterning, and inadequate sleep has been associated with adverse health outcomes, including cardiovascular disorders (CVD). However, the contribution of sleep to socioeconomic inequalities in CVD is unclear. This study pools data from eight European cohorts to investigate the role of sleep duration in the association between life-course socioeconomic status (SES) and CVD.

METHODS AND RESULTS

We used cross-sectional data from eight European cohorts, totalling 111 205 participants. Life-course SES was assessed using father's and adult occupational position. Self-reported sleep duration was categorized into recommended (6-8.5 h/night), long (>8.5 h/night), and short (<6 h/night). We examined two cardiovascular outcomes: coronary heart disease (CHD) and stroke. Main analyses were conducted using pooled data and examined the association between life-course SES and CVD, and the contribution of sleep duration to this gradient using counterfactual mediation. Low father's occupational position was associated with an increased risk of CHD (men: OR = 1.19, 95% CI [1.04; 1.37]; women: OR = 1.25, 95% CI [1.02; 1.54]), with marginal decrease of the gradient after accounting for adult occupational position (men: OR = 1.17, 95% CI [1.02; 1.35]; women: OR = 1.22, 95% CI [0.99; 1.52]), and no mediating effect by short sleep duration. Low adult occupational position was associated with an increased risk of CHD in both men and women (men: OR = 1.48, 95% CI [1.14; 1.92]; women: OR = 1.53, 95% CI [1.04; 2.21]). Short sleep duration meaningfully contributed to the association between adult occupational position and CHD in men, with 13.4% mediation. Stroke did not exhibit a social patterning with any of the variables examined.

CONCLUSION

This study suggests that inadequate sleep accounts to a meaningful proportion of the association between adult occupational position and CHD, at least in men. With sleep increasingly being considered an important cardiovascular risk factor in its own terms, our study additionally points to its potential role in social inequalities in cardiovascular disease.

Affordable, Social, and Substandard Housing and Mortality: The EPIPorto Cohort Study, 1999-2019

Objectives. To examine the association between residence in different housing typologies and all-cause and cause-specific mortality, and to compare with the 25 × 25 risk factors defined by the World Health Organization.Methods. We used data from EPIPorto cohort (Porto, Portugal; n = 2485). We georeferenced and matched participants to a housing type-conventional, affordable, social, or substandard housing (locally called ilhas). We used Poisson regression models to estimate mortality rates and associations.Results. Age- and sex-adjusted mortality rates (per 100 000 person-years) were 713 (95% confidence interval [CI] = 584, 863) for individuals residing in conventional housing, and 1019 (95% CI = 637, 1551), 1200 (95% CI = 916, 1551), and 1239 (95% CI = 839, 1772) for individuals residing in affordable housing, social housing, and ilhas, respectively. After further adjustment, the associations between mortality and residence in social housing (rate ratio [RR] = 1.59; 95% CI = 1.22, 2.06) and in ilhas (RR = 1.64; 95% CI = 1.12, 2.33) remained. The association between disadvantaged housing and mortality was stronger than that observed for well-established risk factors such as hypertension, sedentariness, heavy drinking, manual occupation, or obesity.Conclusions. Disadvantaged housing is a major risk factor for mortality that should be accounted for by health policies and surveillance systems.

Special Report: The Biology of Inequalities in Health: The Lifepath Consortium

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the efficacy of selected policies, and the general implications of our findings for theories and policies. The project adopted a life-course and comparative approach, considering lifetime effects from childhood and adulthood, and pooled data on up to 1.7 million participants of longitudinal cohort studies from Europe, USA, and Australia. These data showed that socioeconomic circumstances predicted mortality and functional decline as strongly as established risk factors currently targeted by global prevention programmes. Analyses also looked at socioeconomically patterned biological markers, allostatic load, and DNA methylation using richly phenotyped cohorts, unraveling their association with aging processes across the life-course. Lifepath studies suggest that socioeconomic circumstances are embedded in our biology from the outset-i.e., disadvantage influences biological systems from molecules to organs. Our findings have important implications for policy, suggesting that (a) intervening on unfavorable socioeconomic conditions is complementary and as important as targeting well-known risk factors, such as tobacco and alcohol consumption, low fruit and vegetable intake, obesity and a sedentary lifestyle, and that (b) effects of preventive interventions in early life integrate interventions in adulthood. The report has an executive summary that refers to the different sections of the main paper.

Measuring Child Socio-Economic Position in Birth Cohort Research: The Development of a Novel Standardized Household Income Indicator

The assessment of early life socioeconomic position (SEP) is essential to the tackling of social inequalities in health. Although different indicators capture different SEP dimensions, maternal education is often used as the only indicator in birth cohort research, especially in multi-cohort analyses. Household income, as a direct measure of material resources, is one of the most important indicators, but one that is underused because it is difficult to measure through questionnaires. We propose a method to construct a standardized, cross-cohort comparable income indicator, the “Equivalized Household Income Indicator (EHII)”, which measures the equivalized disposable household income, using external data from the pan-European Union Statistics on Income and Living Conditions (EUSILC) surveys, and data from the cohorts. We apply this method to four studies, Piccolipiù and NINFEA from Italy and ELFE and EDEN from France, comparing the distribution of EHII with other SEP-related variables available in the cohorts, and estimating the association between EHII and child body mass index (BMI). We found that basic parental and household characteristics may be used, with a fairly good performance, to predict the household income. We observed a strong correlation between EHII and both the self-reported income, whenever available, and other individual socioeconomic-related variables, and an inverse association with child BMI. EHII could contribute to improving research on social inequalities in health, in particular in the context of European birth cohort collaborative studies.

Special Report: The Biology of Inequalities in Health: The Lifepath Consortium

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the efficacy of selected policies, and the general implications of our findings for theories and policies. The project adopted a life-course and comparative approach, considering lifetime effects from childhood and adulthood, and pooled data on up to 1.7 million participants of longitudinal cohort studies from Europe, USA, and Australia. These data showed that socioeconomic circumstances predicted mortality and functional decline as strongly as established risk factors currently targeted by global prevention programmes. Analyses also looked at socioeconomically patterned biological markers, allostatic load, and DNA methylation using richly phenotyped cohorts, unraveling their association with aging processes across the life-course. Lifepath studies suggest that socioeconomic circumstances are embedded in our biology from the outset-i.e., disadvantage influences biological systems from molecules to organs. Our findings have important implications for policy, suggesting that (a) intervening on unfavorable socioeconomic conditions is complementary and as important as targeting well-known risk factors, such as tobacco and alcohol consumption, low fruit and vegetable intake, obesity and a sedentary lifestyle, and that (b) effects of preventive interventions in early life integrate interventions in adulthood. The report has an executive summary that refers to the different sections of the main paper.

Neighbour noise annoyance is associated with various mental and physical health symptoms: results from a nationwide study among individuals living in multi-storey housing

Background

Noise exposure is considered a stressor that may potentially exert negative health effects among the exposed individuals. On a population basis, the most prevalent and immediate response to noise is annoyance, which is an individually experienced phenomenon that may activate physiological stress-responses and result in both physical and mental symptoms. Health implications of traffic noise have been investigated thoroughly, but not of neighbour noise. The aim of the present study was to examine the associations between neighbour noise annoyance and eight different physical and mental health symptoms.

Methods

Cross-sectional data from the Danish Health and Morbidity Survey 2017 were used. The present study included a random sample of 3893 adults living in multi-storey housing. Information on neighbour noise annoyance and various health symptoms (e.g. pain in various body parts, headache, sleeping problems, depression, and anxiety) during the past two weeks was obtained by self-administered questionnaires. The question on neighbour noise annoyance and health symptoms, respectively, had three possible response options: ‘Yes, very annoyed/bothered’, ‘Yes, slightly annoyed/bothered’, ‘No’. The associations between neighbour noise annoyance and very bothering physical and mental health symptoms were investigated using multiple logistic regression models.

Results

Being very annoyed by neighbour noise was significantly associated with higher odds of being very bothered by all eight health symptoms (adjusted OR = 1.73–3.32, all p-values < 0.05) compared to individuals not annoyed by noise from neighbours. Statistically significant interactions were observed between sex and two of the eight health symptoms. Among women, a strong association was observed between neighbour noise annoyance and being very bothered by pain or discomfort in the shoulder or neck, and in the arms, hands, legs, knees, hips or joints. Among men, no associations were observed.

Conclusions

Based on the findings from this study, neighbour noise annoyance is strongly associated with eight different physical and mental health symptoms. Future studies are encouraged to 1) determine the direction of causality using a longitudinal design, 2) explore the biological mechanisms explaining the sex-specific impact of neighbour noise annoyance on symptoms of musculoskeletal pain or discomfort and the other outcomes as well.

Is the association between precarious employment and mental health mediated by economic difficulties in males? Results from two Italian studies

BACKGROUND

Flexible employment is increasing across Europe and recent studies show an association with poor mental health. The goal of the current study is to examine this association in the Italian population to assess the possible mediating role of financial strain.

METHODS

Data were obtained by two Italian cross-sectional studies (PASSI and HIS) aimed at monitoring the general population health status, health behaviours and determinants. Mental health status was assessed using alternatively two validated questionnaires (the PHQ-2 and the MCS-12 score) and Poisson regression models were performed to assess if precarious work was associated with poor mental health. A formal mediation analysis was conducted to evaluate if the association between precarious work and mental health was mediated by financial strain.

RESULTS

The analyses were performed on 31,948 subjects in PASSI and on 21,894 subjects in HIS. A nearly two-fold risk of depression and poor mental health was found among precarious workers, compared to workers with a permanent contract, which was strongly mediated by financial strain.

CONCLUSIONS

Even with the limitations of a cross-sectional design, this research supports that precarious employment contributes through financial strain to reduce the mental health related quality of life and to increase mental disorders such as symptoms of depression or dysthymia. This suggests that when stability in work cannot be guaranteed, it would be appropriate to intervene on the wages of precarious jobs and to provide social safety nets for ensuring adequate income.

Neighbourhood socioeconomic deprivation and allostatic load: a multi-cohort study

Living in deprived neighbourhoods may have biological consequences, but few studies have assessed this empirically. We examined the association between neighbourhood deprivation and allostatic load, a biological marker of wear and tear, taking into account individual's socioeconomic position. We analysed data from three cohort studies (CoLaus-Switzerland; EPIPorto-Portugal; Whitehall II-UK) comprising 16,364 participants. We defined allostatic load using ten biomarkers of dysregulated metabolic, cardiovascular, and inflammatory systems (body mass index; waist circumference; total, high and low density lipoprotein cholesterol; triglycerides; glucose; systolic and diastolic blood pressure; C-reactive protein). Mixed Poisson regression models were fitted to examine associations with neighbourhood deprivation (in quintiles, Q1-least deprived as reference). After adjustment for confounding variables, participants living in the most deprived quintile had 1.13 times higher allostatic load than those living in the least deprived quintile (Relative Risk, RR, for Q2 RR = 1.06, 95% CI 1.03-1.09; Q3 = 1.06, 1.03-1.10; Q4 = 1.09, 1.06-1.12; Q5 = 1.13, 1.09-1.16). This association was partially modified by individual's socioeconomic position, such that the relative risk was higher in participants with low socioeconomic position (Q5 vs Q1 1.16, 1.11-1.22) than those with high socioeconomic position (Q5 vs Q1 1.07, 1.01-1.13). Neighbourhood deprivation is associated with biological wear and tear, suggesting that neighbourhood-level interventions may yield health gains.

Adulthood Socioeconomic Position and Type 2 Diabetes Mellitus-A Comparison of Education, Occupation, Income, and Material Deprivation: The Maastricht Study

In an effort to better quantify the impact of adulthood socioeconomic circumstances on prediabetes and type 2 diabetes (T2DM), we set out to examine the relative importance of four adulthood socioeconomic indicators. Using cross-sectional data from The Maastricht Study on 2011 middle-aged older men and women, our findings indicate that low educational level (OR = 1.81, 95% CI = 1.24-2.64), low occupational level (OR = 1.42, 95% CI = 0.98-2.05), and material deprivation (OR = 1.78, 95% CI = 1.33-2.38) were independently associated with T2DM. Low income (OR = 1.28, 95% CI = 0.88-1.87) was the strongest, albeit not significant, SEP (socioeconomic position) correlate of prediabetes. This association confirms SEP as a multifaceted concept and indicates the need to measure SEP accordingly. In order to tackle the social gradient in prediabetes and T2DM, one should, therefore, address multiple SEP indicators and their possible pathways.

Multi-cohort study identifies social determinants of systemic inflammation over the life course

Chronic inflammation has been proposed as having a prominent role in the construction of social inequalities in health. Disentangling the effects of early life and adulthood social disadvantage on inflammation is key in elucidating biological mechanisms underlying socioeconomic disparities. Here we explore the relationship between socioeconomic position (SEP) across the life course and inflammation (as measured by CRP levels) in up to 23,008 participants from six European cohort studies from three countries conducted between 1958 and 2013. We find a consistent inverse association between SEP and CRP across cohorts, where participants with a less advantaged SEP have higher levels of inflammation. Educational attainment is most strongly related to inflammation, after adjusting for health behaviours, body mass index and later-in-life SEP. These findings suggest socioeconomic disadvantage in young adulthood is independently associated with later life inflammation calling for further studies of the pathways operating through educational processes.

Here, the authors explore the relationship between socioeconomic position (SEP) across the life course and inflammation in a multi-cohort study and show that educational attainment is most strongly related to inflammation, suggesting that socioeconomic disadvantage in young adulthood is independently associated with later life inflammation.

Mortality by occupation-based social class in Italy from 2012 to 2014

OBJECTIVES

Evaluating socio-economic inequality in cause-specific mortality among the working population requires large cohort studies. Through this census-based study, we aimed to quantify disparities in mortality across occupation-based social classes in Italy.

METHODS

We conducted a historical cohort study on a sample of more than 16 million workers. We estimated the mortality rate ratios for each social class, considering upper non-manual workers as reference.

RESULTS

Non-skilled manual workers showed an increased mortality from upper aero-digestive tract, stomach and liver cancers, and from diseases of the circulatory system, transport accidents and suicides in both sexes, and from infectious diseases, diabetes, lung and bladder cancers only in men. Among women, an excess mortality emerged for cervical cancer, whereas mortality from breast and ovarian cancers was lower. When education was taken into account, the excess mortality decreased in men while was no longer significant in women.

CONCLUSIONS

There are remarkable disparities across occupation-based social classes in the Italian working population that favour the upper non-manual workers. Our data could be useful in planning policies for a more effective health and social security system.

Do conceptualisations of health differ across social strata? A concept mapping study among lay people

OBJECTIVES

The legitimacy of policies that aim at tackling socioeconomic inequalities in health can be challenged if they do not reflect the conceptualisations of health that are valued in all strata. Therefore, this study analyses how different socioeconomic groups formulate their own answers regarding: what does health mean to you?

DESIGN

Concept mapping procedures were performed in three groups that differ in educational level. All procedures followed exactly the same design.

SETTING

Area of the city of Utrecht, the Netherlands.

PARTICIPANTS

Lay persons with a lower, intermediate and higher educational level (±15/group).

RESULTS

The concept maps for the three groups consisted of nine, eight and seven clusters each, respectively. Four clusters occurred in all groups: absence of disease/disabilities, health-related behaviours, social life, attitude towards life. The content of some of these differed between groups, for example, behaviours were interpreted as having opportunities to behave healthily in the lower education group, and in terms of their impact on health in the higher education group. Other clusters appeared to be specific for particular groups, such as autonomy (intermediate/higher education group). Finally, ranking ranged from a higher ranking of the positively formulated aspects in the higher education group (eg, lust for life) to that of the negatively formulated aspects in the lower education group (eg, having no chronic disease).

CONCLUSION

Our results provide indications to suggest that people in lower socioeconomic groups are more likely to show a conceptualisation of health that refers to (1) the absence of health threats (vs positive aspects), (2) a person within his/her circumstances (vs quality of own body/mind), (3) the value of functional (vs hedonistic) notions and (4) an accepting (vs active) attitude towards life.

Socioeconomic status, non-communicable disease risk factors, and walking speed in older adults: multi-cohort population based study

OBJECTIVE

To assess the association of low socioeconomic status and risk factors for non-communicable diseases (diabetes, high alcohol intake, high blood pressure, obesity, physical inactivity, smoking) with loss of physical functioning at older ages.

DESIGN

Multi-cohort population based study.

SETTING

37 cohort studies from 24 countries in Europe, the United States, Latin America, Africa, and Asia, 1990-2017.

PARTICIPANTS

109 107 men and women aged 45-90 years.

MAIN OUTCOME MEASURE

Physical functioning assessed using the walking speed test, a valid index of overall functional capacity. Years of functioning lost was computed as a metric to quantify the difference in walking speed between those exposed and unexposed to low socioeconomic status and risk factors.

RESULTS

According to mixed model estimations, men aged 60 and of low socioeconomic status had the same walking speed as men aged 66.6 of high socioeconomic status (years of functioning lost 6.6 years, 95% confidence interval 5.0 to 9.4). The years of functioning lost for women were 4.6 (3.6 to 6.2). In men and women, respectively, 5.7 (4.4 to 8.1) and 5.4 (4.3 to 7.3) years of functioning were lost by age 60 due to insufficient physical activity, 5.1 (3.9 to 7.0) and 7.5 (6.1 to 9.5) due to obesity, 2.3 (1.6 to 3.4) and 3.0 (2.3 to 4.0) due to hypertension, 5.6 (4.2 to 8.0) and 6.3 (4.9 to 8.4) due to diabetes, and 3.0 (2.2 to 4.3) and 0.7 (0.1 to 1.5) due to tobacco use. In analyses restricted to high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was 8.0 (5.7 to 13.1) for men and 5.4 (4.0 to 8.0) for women, whereas in low and middle income countries it was 2.6 (0.2 to 6.8) for men and 2.7 (1.0 to 5.5) for women. Within high income countries, the number of years of functioning lost attributable to low socioeconomic status by age 60 was greater in the United States than in Europe. Physical functioning continued to decline as a function of unfavourable risk factors between ages 60 and 85. Years of functioning lost were greater than years of life lost due to low socioeconomic status and non-communicable disease risk factors.

CONCLUSIONS

The independent association between socioeconomic status and physical functioning in old age is comparable in strength and consistency with those for established non-communicable disease risk factors. The results of this study suggest that tackling all these risk factors might substantially increase life years spent in good physical functioning.