Interpreting mutual adjustment for multiple indicators of socioeconomic position without committing mutual adjustment fallacies

Health-related quality of life and impact of socioeconomic status among primary and secondary school students after the third COVID-19 wave in Berlin, Germany

In the earlier phases of the COVID-19 pandemic, studies in Germany and elsewhere found an overall reduction in health-related quality of life (HRQoL) among students. However, there is little evidence on later pandemic stages as well as socioeconomic influencing factors. We aimed to (1) describe HRQoL in a Berlin student cohort at two time points in mid-2021, and to (2) analyze the effects of household income and education. We assessed HRQoL of students from 24 randomly selected primary and secondary schools in Berlin, Germany, with the KIDSCREEN-10 index in June and September 2021. To adjust for non-response bias, inverse probability weighting was applied. The potential effects of both household income and education (lower vs. higher) were estimated in generalized linear mixed models, based on prior assumptions presented in directed acyclic graphs. Our cohort comprised 660 students aged 7-19 years. In June 2021, 11.3% [95% CI = 9.0% - 14.0%] reported low HRQoL, whereas in September 2021, this increased to 13.7% [95% CI = 11.1% - 16.5%], with adolescent girls more frequently reporting low HRQoL at both time points (20% [95% CI = 17.1% - 23.3%] and 29% [95% CI = 25.5% - 32.5%]) compared to boys and younger children. While there was no statistically significant total effect of lower household income on HRQoL, a negative effect of lower household education was statistically significant (β = -2.15, SE 0.95, 95% CI = -4.01 to -0.29, p = 0.024). In summary, students' HRQoL in mid-2021 was better than that documented in other studies conducted at pandemic onset using KIDSCREEN-10. Female adolescents reported low HRQoL more often, and lower household education significantly reduced children's HRQoL. Support strategies for psychosocial wellbeing should consider socioeconomically disadvantaged children as important target groups.

Socioeconomic Position and Health Among Children and Adolescents With CKD Across the Life-Course

Children and adolescents in families of lower socioeconomic position (SEP) experience an inequitable burden of reduced access to healthcare and poorer health. For children living with chronic kidney disease (CKD), disadvantaged SEP may exacerbate their considerable disease burden. Across the life-course, CKD may also compromise the SEP of families and young people, leading to accumulating health and socioeconomic disadvantage. This narrative review summarizes the current evidence on relationships of SEP with kidney care and health among children and adolescents with CKD from a life-course approach, including impacts of family SEP on kidney care and health, and bidirectional impacts of CKD on SEP. It highlights relevant conceptual models from social epidemiology, current evidence, clinical and policy implications, and provides directions for future research. Reflecting the balance of available evidence, we focus primarily on high-income countries (HICs), with an overview of key issues in low- and middle-income countries (LMICs). Overall, a growing body of evidence indicates sobering socioeconomic inequities in health and kidney care among children and adolescents with CKD, and adverse socioeconomic impacts of CKD. Dedicated efforts to tackle inequities are critical to ensuring that all young people with CKD have the opportunity to live long and flourishing lives. To prevent accumulating disadvantage, the global nephrology community must advocate for local government action on upstream social determinants of health; and adopt a life-course approach to kidney care that proactively identifies and addresses unmet social needs, targets intervening factors between SEP and health, and minimizes adverse socioeconomic outcomes across financial, educational and vocational domains.

Changes in maternal psychological symptom profiles from 2 to 6 months postpartum: an application of latent transition analysis

To identify subgroups of postpartum women with different psychological symptom profiles at 2 and 6 months postpartum and to examine how they transition between symptom profiles over time using latent transition analysis (LTA). We used secondary data from the Family Life Project (N = 1,117) and performed LTA based on observed variables (depression, anxiety, somatization, and hostility). We examined transition probabilities and changes in latent status prevalence from 2 to 6 months postpartum. Considering the known influences of social determinants of health on psychological symptoms, bivariate analyses were conducted to describe the characteristics of different transition patterns. A 3-class model with better fit indices, entropy, and interpretability was selected. Based on symptom severity, the identified profiles were Profile 1: Low, Profile 2: Moderate, and Profile 3: High. From 2 to 6 months postpartum, the prevalence of low symptom profile decreased (82 to 78.2%) while the prevalence increased for moderate (15.8 to 17.5%) and high symptom profiles (2.2 to 4.4%). For all profiles, it was most likely for postpartum women to stay in the same profile from 2 to 6 months (low to low, moderate to moderate, and high to high). Those in persistent or worsening transition patterns were significantly younger or had less social support or education. Postpartum women in moderate or high symptom profiles at 2 months were most likely to stay in the same profile at 6 months postpartum, indicating persistent symptom burden. Clinicians should consider providing early, targeted support to prevent persistent symptom burden.

Life course epidemiology and public health

Life course epidemiology aims to study the effect of exposures on health outcomes across the life course from a social, behavioural, and biological perspective. In this Review, we describe how life course epidemiology changes the way the causes of chronic diseases are understood, with the example of hypertension, breast cancer, and dementia, and how it guides prevention strategies. Life course epidemiology uses complex methods for the analysis of longitudinal, ideally population-based, observational data and takes advantage of new approaches for causal inference. It informs primordial prevention, the prevention of exposure to risk factors, from an eco-social and life course perspective in which health and disease are conceived as the results of complex interactions between biological endowment, health behaviours, social networks, family influences, and socioeconomic conditions across the life course. More broadly, life course epidemiology guides population-based and high-risk prevention strategies for chronic diseases from the prenatal period to old age, contributing to evidence-based and data-informed public health actions. In this Review, we assess the contribution of life course epidemiology to public health and reflect on current and future challenges for this field and its integration into policy making.

Examination of Social Determinants of Health Characteristics Influencing Maternal Postpartum Symptom Experiences

Postpartum women experience multiple, co-occurring postpartum symptoms. It is unknown if social determinants of health (SDOH) influence postpartum symptom typologies. This secondary analysis used the Community and Child Health Network study data. Participants included for analysis varied depending on the availability of the SDOH data (N = 851 to 1784). Bivariate and multiple regression analyses were conducted to examine the association between SDOH and previously identified postpartum symptom typologies. Area under the receiver operating characteristics curve (AUROC) was calculated to examine if adding SDOH variables contributes to predicting postpartum symptom typologies. The adjusted odds (aOR) of being in high symptom severity or occurrence typologies were greater for participants who had less than high school education (aOR = 2.29), experienced healthcare discrimination (aOR = 2.21), used governmental aid (aOR = 2.11), or were food insecure (aOR = 2.04). AUROC improved after adding SDOH. Considering experiences of different social-economic hardships influence postpartum symptom typologies, future practice and research should address SDOH to improve postpartum symptom experiences.

Re: Cillekens B, Huysmans MA, Holtermann A, van Mechelen W, Straker L, Krause N, van der Beek AJ, Coenen P. Physical activity at work may not be health enhancing. A systematic review with meta-analysis on the association between occupational physical activity and cardiovascular disease mortality covering 23 studies with 655 892 participants. Scand J Work Environ Health. 2022;48(2):86-98. doi:10.5271/sjweh.3993

Objectives

Emerging evidence suggests contrasting health effects for leisure-time and occupational physical activity. In this systematic review, we synthesized and described the epidemiological evidence regarding the association between occupational physical activity and cardiovascular disease (CVD) mortality.

Methods

A literature search was performed in PubMed, Embase, CINAHL, PsycINFO and Evidence-Based Medicine Reviews, from database inception to 17 April 2020. Articles were included if they described original observational prospective research, assessing the association between occupational physical activity and CVD mortality among adult workers. Reviews were included if they controlled for age and gender and at least one other relevant variable. We performed meta-analyses on the associations between occupational physical activity and CVD mortality.

Results

We screened 3345 unique articles, and 31 articles (from 23 studies) were described in this review. In the meta-analysis, occupational physical activity showed no significant association with overall CVD mortality for both males [hazard ratio (HR) 0.97, 95% confidence interval (CI) 0.84–1.12] and females (HR 0.97, 95% CI 0.82–1.15). Additional analysis showed that higher levels of occupational physical activity were non-significantly associated with a 9% increase in studies reporting on the outcome ischemic heart disease mortality (HR 1.09, 95% CI 0.82–1.43).

Conclusions

While the beneficial association between leisure-time physical activity and CVD mortality has been widely documented, occupational physical activity was not found to have a beneficial association with CVD mortality. This observation may have implications for our appreciation of the association between physical activity and health for workers in physically demanding jobs, as occupational physical activity may not be health enhancing.

Socioeconomic position and eye health outcomes: identifying inequality in rapid population-based surveys

OBJECTIVE

Monitoring health outcomes disaggregated by socioeconomic position (SEP) is crucial to ensure no one is left behind in efforts to achieve universal health coverage. In eye health planning, rapid population surveys are most commonly implemented; these need an SEP measure that is feasible to collect within the constraints of a streamlined examination protocol. We aimed to assess whether each of four SEP measures identified inequality-an underserved group or socioeconomic gradient-in key eye health outcomes.

DESIGN

Population-based cross-sectional survey.

PARTICIPANTS

A subset of 4020 adults 50 years and older from a nationally representative sample of 9188 adults aged 35 years and older in The Gambia.

OUTCOME MEASURES

Blindness (presenting visual acuity (PVA) <3/60), any vision impairment (VI) (PVA <6/12), cataract surgical coverage (CSC) and effective cataract surgical coverage (eCSC) at two operable cataract thresholds (<6/12 and <6/60) analysed by one objective asset-based measure (EquityTool) and three subjective measures of relative SEP (a self-reported economic ladder question and self-reported household food adequacy and income sufficiency).

RESULTS

Subjective household food adequacy and income sufficiency demonstrated a socioeconomic gradient (queuing pattern) in point estimates of any VI and CSC and eCSC at both operable cataract thresholds. Any VI, CSC <6/60 and eCSC <6/60 were worse among people who reported inadequate household food compared with those with just adequate food. Any VI and CSC <6/60 were worse among people who reported not enough household income compared with those with just enough income. Neither the subjective economic ladder question nor the objective asset-wealth measure demonstrated any socioeconomic gradient or pattern of inequality in any of the eye health outcomes.

CONCLUSION

We recommend pilot-testing self-reported food adequacy and income sufficiency as SEP variables in vision and eye health surveys in other locations, including assessing the acceptability, reliability and repeatability of each question.

Association of Area-Based Socioeconomic Measures with Tuberculosis Incidence in California

We assessed the association of area-based socio-economic status (SES) measures with tuberculosis (TB) incidence in California. We used TB disease data for 2012-2016 (n = 9901), population estimates, and SES measures to calculate incidence rates, rate ratios, and 95% confidence intervals (95% CI) by SES and birth country. SES was measured by census tract and was categorized by quartiles for education, crowding, and the California Healthy Places Index (HPI)and by specific cutoffs for poverty. The lowest SES areas defined by education, crowding, poverty, and HPI had 39%, 40%, 41%, and 33% of TB cases respectively. SES level was inversely associated with TB incidence across all SES measures and birth countries. TB rates were 3.2 (95% CI 3.0-3.4), 2.1 (95% CI 1.9-2.2), 3.6 (95% CI 3.3-3.8), and 2.0 (95% CI 1.9-2.1) times higher in lowest SES areas vs. highest SES areas as defined by education, crowding, poverty and HPI respectively. Area-based SES measures are associated with TB incidence in California. This information could inform TB prevention efforts in terms of materials, partnerships, and prioritization.

The association between socioeconomic status and the 90-day risk of cardiovascular events after total hip arthroplasty - registry-based study of 103,286 patients

BACKGROUND AND PURPOSE

Patients receiving a total hip arthroplasty (THA) are subsequently at an increased risk of cardiovascular disease (CVD). Further, socioeconomic status (SES) has an effect on CVD. We evaluated whether low SES is associated with a higher risk of readmission due to CVD after THA within 90 days in a setting with universal tax-supported healthcare.

PATIENTS AND METHODS

We performed a nationwide population-based cohort study using Danish health registries from 1995 to 2017. Individual-based information on SES markers (cohabitation, education, income, and liquid assets) was obtained for all participants. The outcome was any hospital-treated CVD. The data was transformed using the pseudo-observation method to enable an estimation of the adjusted risk ratios (RRs) with 95% confidence intervals (CI) for each marker using generalized linear regression.

RESULTS

Among 103,286 THA patients, 452 were hospitalized with CVD within 90 days after surgery. Low SES seemed to be associated with a small increased risk of CVD, as the RRs for any CVD were 1.1 (95% CI 0.7-1.7) for patients living alone vs. cohabiting, 1.3 (CI 0.7- .3) for low education vs. high, 1.4 (CI 0.8-2.6) for low income vs. high, and 1.3 (CI 0.8-2.1) for low liquid assets vs. high.

CONCLUSION

Living alone, low education, low income, and low liquid assets seem to be associated with a small increased risk of readmission due to CVD 90 days after THA. Wide confidence intervals in risk should be considered when interpreting the study results.

Intergenerational Social Mobility and Allostatic Load in Midlife and Older Ages: A Diagonal Reference Modeling Approach

OBJECTIVES

This study aims to understand the association of life-course intergenerational social mobility with allostatic load (AL) burden in midlife and older ages in Ireland.

METHODS

The study involved biological data for 3,987 older adults participating in The Irish Longitudinal Study on Ageing (TILDA). Intergenerational social mobility was characterized using the cross-classification of origin socioeconomic position (SEP; i.e., father's occupation) and destination SEP (i.e., own occupation). AL was operationalized using 12 biomarkers tapping cardiovascular, metabolic, renal, and immune system dysregulation. Diagonal reference modeling (DRM) and ordinary least square regression techniques were applied to explore the effect of social mobility on AL burden.

RESULTS

A total of 55.5% experienced intergenerational mobility: 37.5% were upwardly mobile, 18.0% were downwardly mobile. A social gradient in AL was observed among the socially non-mobile. Destination SEP (b = 0.74, 95% CI = 0.57, 0.92) predominated in influence over origin, although both life stages exerted significant influence on later-life AL. Social mobility in either direction was not associated with AL burden. Mobility coefficients were substantially small across a large variety of model specifications.

DISCUSSION

Findings provide evidence for an accumulation model of social inequalities in which disparities in health are diluted rather than increased by social mobility (i.e., gradient constraint), with the socially mobile having an AL score that is intermediate between their origin class and destination class. This implies that the effects of origin SEP on health are not immutable, but are instead responsive to changing socioeconomic circumstances across the life course.

Avoiding overadjustment bias in social epidemiology through appropriate covariate selection: a primer

Obtaining accurate estimates of the causal effects of socioeconomic position (SEP) on health is important for public health interventions. To do this, researchers must identify and adjust for all potential confounding variables while avoiding inappropriate adjustment for mediator variables on a causal pathway between the exposure and outcome. Unfortunately, 'overadjustment bias' remains a common and under-recognised problem in social epidemiology. This paper offers an introduction to selecting appropriate variables for adjustment when examining effects of SEP on health, with a focus on overadjustment bias. We discuss the challenges of estimating different causal effects including overadjustment bias, provide guidance on overcoming them, and consider specific issues including the timing of variables across the life-course, mutual adjustment for socioeconomic indicators, and conducting systematic reviews. We recommend three key steps to select the most appropriate variables for adjustment. First, researchers should be clear about their research question and causal effect of interest. Second, using expert knowledge and theory, researchers should draw causal diagrams representing their assumptions about the interrelationships between their variables of interest. Third, based on their causal diagram(s) and causal effect(s) of interest, researchers should select most appropriate set of variables, which maximises adjustment for confounding while minimising adjustment for mediators.

Physical activity at work may not be health enhancing. A systematic review with meta-analysis on the association between occupational physical activity and cardiovascular disease mortality covering 23 studies with 655 892 participants

OBJECTIVES

Emerging evidence suggests contrasting health effects for leisure-time and occupational physical activity. In this systematic review, we synthesized and described the epidemiological evidence regarding the association between occupational physical activity and cardiovascular disease (CVD) mortality.

METHODS

A literature search was performed in PubMed, Embase, CINAHL, PsycINFO and Evidence-Based Medicine Reviews, from database inception to 17 April 2020. Articles were included if they described original observational prospective research, assessing the association between occupational physical activity and CVD mortality among adult workers. Reviews were included if they controlled for age and gender and at least one other relevant variable. We performed meta-analyses on the associations between occupational physical activity and CVD mortality.

RESULTS

We screened 3345 unique articles, and 31 articles (from 23 studies) were described in this review. In the meta-analysis, occupational physical activity showed no significant association with overall CVD mortality for both males [hazard ratio (HR) 1.00, 95% confidence interval (CI) 0.87-1.15] and females (HR 0.95, 95% CI 0.82-1.09). Additional analysis showed that higher levels of occupational physical activity were non-significantly associated with a 15% increase in studies reporting on the outcome ischemic heart disease mortality (HR 1.15, 95% CI 0.88-1.49).

CONCLUSIONS

While the beneficial association between leisure-time physical activity and CVD mortality has been widely documented, occupational physical activity was not found to have a beneficial association with CVD mortality. This observation may have implications for our appreciation of the association between physical activity and health for workers in physically demanding jobs, as occupational physical activity may not be health enhancing.

The association between socioeconomic status and the 30- and 90-day risk of infection after total hip arthroplasty : a registry-based cohort study of 103,901 patients with osteoarthritis

AIMS

The aim of this study was to examine whether socioeconomic status (SES) is associated with a higher risk of infections following total hip arthroplasty (THA) at 30 and 90 days.

METHODS

We obtained individual-based information on SES markers (cohabitation, education, income, and savings) on 103,901 THA patients from Danish health registries between 1 January 1995 and 31 December 2017. The primary outcome measure was any hospital-treated infection (i.e. all infections). The secondary outcomes were further specified to specific hospital-treated infections (pneumonia, urinary tract infection, and periprosthetic joint infection). The primary timepoint was within 90 days. In addition, the outcomes were further evaluated within 30 days. We calculated the cumulative incidence, and used the pseudo-observation method and generalized linear regression to estimate adjusted risk ratios (RRs) with 95% confidence intervals (CIs) for each marker.

RESULTS

The cumulative incidence of any infection at 90 days was highest in patients who lived alone (1.5% (95% CI 1.3 to 1.6)) versus cohabitant (0.7% (95% CI 0.7 to 0.8)), had the lowest educational achievement (1.1% (95% CI 1.0 to 1.2)) versus highest (0.7% (95% CI 0.5 to 0.8)), had the lowest income (1.6% (95% CI 1.5 to 1.70)) versus highest (0.4% (95% CI 0.3 to 0.5)), or had lowest savings (1.3% (95% CI 1.2 to 1.4)) versus highest (0.7% (95% CI 0.6 to 0.8)). Within 90 days, the RRs for any infection were 1.3 (95% CI 1.2 to 1.4) for patients living alone versus cohabiting, 1.2 (95% CI 1.0 to 1.3) for low education achievement versus high, 1.7 (95% CI 1.4 to 2.1) for low income versus high income, and 1.5 (95% CI 1.4 to 1.8) for low savings versus high savings. The same trends were also seen for any infections within the first 30 days.

CONCLUSION

Our study provides evidence that socioeconomic inequality adversely influences the risk of infection after THA, thus contributing to healthcare disparities and inequalities. We found that living alone, low educational achievement, low income, or low savings were associated with higher risks of infections within the first 30 and 90 days after THA. Therefore, the development of targeted intervention strategies with the aim of increasing awareness of patients identified as being at greatest risk is needed to mitigate the impact of SES on the risk of infections following THA. Cite this article: Bone Joint J 2022;104-B(2):221-226.

Female reproductive factors and risk of joint replacement arthroplasty of the knee and hip due to osteoarthritis in postmenopausal women: a nationwide cohort study of 1.13 million women

OBJECTIVES

Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women.

METHODS

We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model.

RESULTS

During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects.

CONCLUSION

We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

Exploring equity in accessing diabetes management treatment: A healthcare gap analysis

Healthcare inequities are often investigated empirically as associations between socio-economic characteristics and differences between observed healthcare utilisation and estimates of needs-based utilisation. However, the concept of 'need' is tricky to operationalise and utilisation may be contingent on inequities arising at an earlier stage. In this study, we apply a unique combination of register and survey data collected in 2019 to assess equity in opportunities to access treatment for patients with recently diagnosed type 2 diabetes. In the study of this population (N = 1864) we escape the challenge of estimating needs by arguing that need can be approximated from treatment guidelines within a nationwide framework of disease management programmes. Furthermore, instead of observed utilisation we use patient reports on whether they have been offered treatment as a measure of opportunities to access multiple components of care, that is, we focus on possible inequalities arising prior to possible utilisation inequalities. 'Healthcare gaps' are computed as the discrepancy between an index of guideline recommended treatments and patients' perceived offers of treatments, thus providing a novel take on the 'healthcare deprivation profiles' approach to the study of healthcare inequalities. Using this method, we explore and document inequalities along multiple dimensions of familiar socio-economic factors (income, education, occupation) as well as self-reported barriers to access. We also provide supporting evidence that healthcare gaps, as measured in our study, are associated with poorer quality of care, and that those who experience large gaps are more likely to be disadvantaged in terms of self-reported difficulties in relation to key self-care aspects. We conclude that even in a health system with comprehensive universal coverage, healthcare inequity can arise already at the stage of offering access to preventive treatment. The results warrant further research into the causes, consequences and remedies of such inequities.

Impact of socioeconomic status on the 90- and 365-day rate of revision and mortality after primary total hip arthroplasty: a cohort study based on 103,901 patients with osteoarthritis from national databases in Denmark

Background and purpose - Socioeconomic inequality in health is recognized as an important public health issue. We examined whether socioeconomic status (SES) is associated with revision and mortality rates after total hip arthroplasty (THA) within 90 and 365 days.Patients and methods - We obtained SES markers (cohabitation, education, income, and liquid assets) on 103,901 THA patients from Danish health registers (year 1995-2017). The outcomes were any revision (all revisions), specified revision (due to infection, fracture, or dislocation), and mortality. We used Cox regression analysis to estimate adjusted hazard ratio (aHR) of each outcome with 95% confidence interval (CI) for each SES marker.Results - Within 90 days, the aHR for any revision was 1.3 (95% CI 1.1-1.4) for patients living alone vs. cohabiting. The aHR was 2.0 (CI 1.4-2.6) for low-income vs. high-income among patients < 65 years. The aHR was 1.2 (CI 0.9-1.7) for low liquid assets among patients > 65 years. Results were consistent for any revision within 365 days as well as for revisions due to infection, fracture, and dislocation. The aHR for mortality was 1.4 (CI 1.2-1.6) within 90 days and 1.3 (CI 1.2-1.5) within 365 days for patients living alone vs. cohabiting. Low education, low income, and low liquid assets were associated with increased mortality rate within both 90 and 365 days.Interpretation - Our results suggest that living alone, low income, and low liquid assets were associated with increased revision and mortality up to 365 days after THA surgery. Optimizing medical conditions prior to surgery and implementing different post-THA support strategies with a focus on vulnerable patients may reduce complications associated with inequality.

Socioeconomic position and prognosis in premenopausal breast cancer: a population-based cohort study in Denmark

BACKGROUND

To investigate how socioeconomic position (SEP) influences the effectiveness of cancer-directed treatment in premenopausal breast cancer patients in terms of breast cancer recurrence and mortality.

METHODS

We conducted a cohort study nested in the ProBeCaRe (Predictors of Breast Cancer Recurrence) cohort (n = 5959). We identified all premenopausal women aged 18-55 years diagnosed with non-metastatic breast cancer and prescribed docetaxel-based chemotherapy in Denmark during 2007-2011. Population-based administrative registries provided data on SEP: marital status (married including registered partnership or single including divorced or widowed), cohabitation (cohabiting or living alone), education (low, intermediate, or high), income (low, medium, or high), and employment status (employed, unemployed, or health-related absenteeism). For each SEP measure, we computed incidence rates, cumulative incidence proportions (CIPs), and used Poisson regression to compute incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of recurrence and death. We stratified on estrogen receptor (ER) status/tamoxifen to evaluate interaction.

RESULTS

Our study cohort included 2616 women; 286 (CIP 13%) experienced recurrence and 223 (CIP 11%) died during follow-up (median 6.6 and 7.2 years, respectively). Single women had both increased 5-year risks of recurrence (IRR 1.45, 95% CI 1.11-1.89) and mortality (IRR 1.83, 95% CI 1.32-2.52). Furthermore, we observed increased 5-year mortality in women with low education (IRR 1.49, 95% CI 0.95-2.33), low income (IRR 1.37, 95% CI 0.83-2.28), unemployment (IRR 1.61, 95% CI 0.83-3.13), or health-related work absenteeism (IRR 1.80, 95% CI 1.14-2.82), but smaller or no increased risk of recurrence. These findings were especially evident among women with ER+ tumors prescribed tamoxifen. Overall analyses (follow-up max. 10 years) provided similar results.

CONCLUSIONS

Low SEP in premenopausal women with non-metastatic breast cancer was associated with increased mortality, but not always recurrence. This suggests underdetection of recurrences in certain groups. Poor prognosis in women with low SEP, especially single women, may partly be explained by tamoxifen adherence.

Socio-economic distribution of e-cigarette use among recent former regular smokers and current smokers at ages 25-26 in England

BACKGROUND AND AIMS

E-cigarettes may potentially help young adult smokers to quit smoking, yet little is known about differences among socio-economic groups. We examined associations between key socio-economic characteristics and e-cigarette use among recent former smokers and current smokers in a sample of young adults in England.

DESIGN, SETTING, PARTICIPANTS AND MEASUREMENTS

We used data on 346 recent former regular (daily for 12+ months) smokers and 1913 current smokers from the ages 25-26 wave of the Next Steps cohort study (2015-2016). In multinomial logistic regression, we estimated relative risk ratios (RRR) of e-cigarette use (never, former, non-daily, daily) by educational attainment, social class [using the National Statistics Socio-economic classification (NS-SEC)] and employment status [full-time, part-time, unemployed and other 'inactivity' (e.g. stay-at-home parents and permanantly disabled)], adjusting for sex.

FINDINGS

Among recent former regular smokers, there were no patterns of association between socio-economic characteristics and e-cigarette use. Among current smokers: (1) compared with higher occupation (NS-SEC I/II), intermediate occupation (NS-SEC III/IV) was positively associated with non-daily e-cigarette use [RRR = 1.77, 95% confidence interval (CI) = 1.03-3.03]; (2) compared with full-time employment, unemployment was negatively associated with non-daily and daily e-cigarette use (RRR = 0.38, 95% CI = 0.18-0.81; RRR = 0.12, 95% CI = 0.02-0.56) and other economic inactivity was negatively associated with daily e-cigarette use (RRR = 0.39, 95% CI = 0.16-0.93).

CONCLUSIONS

Among young adult smokers in England, lower-status occupational groups were more likely to use e-cigarettes on a non-daily basis than to have never used compared with higher status occupational groups. Compared with people in full-time employment, those without employment were less likely to use e-cigarettes daily than to have never used.

Trends in socioeconomic inequalities in premature and avoidable mortality in Canada, 1991-2016

BACKGROUND

Recent epidemiologic findings suggest that socioeconomic inequalities in health may be widening over time. We examined trends in socioeconomic inequalities in premature and avoidable mortality in Canada.

METHODS

We conducted a population-based repeated cohort study using the 1991, 1996, 2001, 2006 and 2011 Canadian Census Health and Environment Cohorts. We linked individual-level Census records for adults aged 25-74 years to register-based mortality data. We defined premature mortality as death before age 75 years. For each census cohort, we estimated age-standardized rates, risk differences and risk ratios for premature and avoidable mortality by level of household income and education.

RESULTS

We identified 16 284 045 Census records. Between 1991 and 2016, premature mortality rates declined in all socioeconomic groups except for women without a high school diploma. Absolute income-related inequalities narrowed among men (from 2478 to 1915 deaths per 100 000) and widened among women (from 1008 to 1085 deaths per 100 000). Absolute education-related inequalities widened among men and women. Relative socioeconomic inequalities in premature mortality widened progressively over the study period. For example, the relative risk of premature mortality associated with the lowest income quintile increased from 2.10 (95% confidence interval [CI] 2.02-2.17) to 2.79 (95% CI 2.66-2.91) among men and from 1.72 (95% CI 1.63- 1.81) to 2.50 (95% CI 2.36-2.64) among women. Similar overall trends were observed for avoidable mortality.

INTERPRETATION

Socioeconomically disadvantaged groups have not benefited equally from recent declines in premature and avoidable mortality in Canada. Efforts to reduce socioeconomic inequalities and associated patterns of disadvantage are necessary to prevent this pattern of widening health inequalities from persisting or worsening over time.

Factors Explaining Socio-Economic Inequalities in Cancer Survival: A Systematic Review

BACKGROUND

There is strong and well-documented evidence that socio-economic inequality in cancer survival exists within and between countries, but the underlying causes of these differences are not well understood.

METHODS

We systematically searched the Ovid Medline, EMBASE, and CINAHL databases up to 31 May 2020. Observational studies exploring pathways by which socio-economic position (SEP) might causally influence cancer survival were included.

RESULTS

We found 74 eligible articles published between 2005 and 2020. Cancer stage, other tumor characteristics, health-related lifestyle behaviors, co-morbidities and treatment were reported as key contributing factors, although the potential mediating effect of these factors varied across cancer sites. For common cancers such as breast and prostate cancer, stage of disease was generally cited as the primary explanatory factor, while co-morbid conditions and treatment were also reported to contribute to lower survival for more disadvantaged cases. In contrast, for colorectal cancer, most studies found that stage did not explain the observed differences in survival by SEP. For lung cancer, inequalities in survival appear to be partly explained by receipt of treatment and co-morbidities.

CONCLUSIONS

Most studies compared regression models with and without adjusting for potential mediators; this method has several limitations in the presence of multiple mediators that could result in biased estimates of mediating effects and invalid conclusions. It is therefore essential that future studies apply modern methods of causal mediation analysis to accurately estimate the contribution of potential explanatory factors for these inequalities, which may translate into effective interventions to improve survival for disadvantaged cancer patients.

Influence of Chinese New Year overlapping COVID-19 lockdown on HONO sources in Shijiazhuang

Nitrous acid (HONO) is an important precursor of hydroxyl radical (OH) in the atmosphere. It is also toxic to human health. In this work, HONO concentrations were measured in Shijiazhuang using a Monitor for AeRosols and Gases in ambient Air (MARGA) from December 15, 2019 to March 15, 2020, which covered the heavy air pollution season, the Chinese New Year (CNY) vocation and the Corona Virus Disease-19 (COVID-19) lockdown period. During & after CNY overlapping COVID-19 lockdown, the air quality was significantly improved because of both the emission reduction and the increase in diffusion ability of air masses. The mean HONO concentration was 2.43 ± 1.08 ppbv before CNY, while it decreased to 1.53 ± 1.16 ppbv during CNY and 0.97 ± 0.76 ppbv after CNY. The lockdown during & after CNY reduced ~31% of ambient HONO along with ~62% of NO and ~36% of NO2 compared with those before CNY after the improvement of diffusion ability had been taken into consideration. Heterogeneous reaction of NO2 on ground surface dominated the nocturnal HONO sources, followed by heterogeneous reaction on aerosol surface, vehicle emission, reaction between NO and OH and emission from soil on pollution days throughout the observation. Except for elevated soil emission, other nighttime HONO sources and sinks decreased significantly during & after CNY. The relative importance of heterogeneous reaction of NO2 on surfaces further increased because of both the decrease in vehicle emission and the increase in the heterogeneous conversion kinetics from NO2 to HONO during & after CNY.

Modifiable and non-modifiable risk factors for COVID-19, and comparison to risk factors for influenza and pneumonia: results from a UK Biobank prospective cohort study

OBJECTIVES

We aimed to investigate demographic, lifestyle, socioeconomic and clinical risk factors for COVID-19, and compared them to risk factors for pneumonia and influenza in UK Biobank.

DESIGN

Cohort study.

SETTING

UK Biobank.

PARTICIPANTS

49-83 year olds (in 2020) from a general population study.

MAIN OUTCOME MEASURES

Confirmed COVID-19 infection (positive SARS-CoV-2 test). Incident influenza and pneumonia were obtained from primary care data. Poisson regression was used to study the association of exposure variables with outcomes.

RESULTS

Among 235 928 participants, 397 had confirmed COVID-19. After multivariable adjustment, modifiable risk factors were higher body mass index and higher glycated haemoglobin (HbA1C) (RR 1.28 and RR 1.14 per SD increase, respectively), smoking (RR 1.39), slow walking pace as a proxy for physical fitness (RR 1.53), and use of blood pressure medications as a proxy for hypertension (RR 1.33). Higher forced expiratory volume in 1 s (FEV1) and high-density lipoprotein (HDL) cholesterol were both associated with lower risk (RR 0.84 and RR 0.83 per SD increase, respectively). Non-modifiable risk factors included male sex (RR 1.72), black ethnicity (RR 2.00), socioeconomic deprivation (RR 1.17 per SD increase in Townsend Index), and high cystatin C (RR 1.13 per SD increase). The risk factors overlapped with pneumonia somewhat, less so for influenza. The associations with modifiable risk factors were generally stronger for COVID-19, than pneumonia or influenza.

CONCLUSION

These findings suggest that modification of lifestyle may help to reduce the risk of COVID-19 and could be a useful adjunct to other interventions, such as social distancing and shielding of high risk.

Testing sampling bias in estimates of adolescent social competence and behavioral control

In 5 of the 6 large Dutch developmental cohorts investigated here, lower SES adolescents are underrepresented and higher SES adolescents overrepresented. With former studies clearly revealing differences between SES strata in adolescent social competence and behavioral control, this misrepresentation may contribute to an overestimation of normative adolescent competence. Using a raking procedure, we used national census statistics to weigh the cohorts to be more representative of the Dutch population. Contrary to our expectations, in all cohorts, little to no differences between SES strata were found in the two outcomes. Accordingly, no differences between weighted and unweighted mean scores were observed across all cohorts. Furthermore, no clear change in correlations between social competence and behavioral control was found. These findings are most probably explained by the fact that measures of SES in the samples were quite limited, and the low SES participants in the cohorts could not be considered as representative of the low SES groups in the general population. Developmental outcomes associated with SES may be affected by a raking procedure in other cohorts that have a sufficient number and sufficient variation of low SES adolescents.

Highways to Ageing - Linking life course SEP to multivariate trajectories of health outcomes in older adults

OBJECTIVES

Ageing is a temporal, multi-faceted process subject to interacting factors. In this study, we used life course and multidimensional approaches to elucidate the association between socioeconomic forces across a lifetime and the developmental origins in health and disease of the Mexican elderly.

METHODS

Data stemmed from the Mexican Health and Ageing Study, constituting a sample of older adults (N= 5169, ≥50 years). With retrospective information on early, intermediary and contemporaneous socioeconomic indicators, life course typologies of socioeconomic position were identified using Latent Class Analysis. Based on prospective data of functional mobility, number of chronic conditions and self-rated health, multivariate trajectories of health outcomes were uncovered with Group Based Trajectory Model. Links between the extracted SEP and multivariate health latent constructs were explored with multinomial logistic regression.

RESULTS

Life course SEP classes were heterogeneous, yet a large proportion of subjects was characterized by persistent socioeconomic adversity throughout life. The health outcomes' patterns of co-evolution were diverse too, shedding light on the nature of their developmental links, while revealing variable synchronicity in their temporal decline. A graded association was observed between the life course SEP classes and ageing trajectories.

CONCLUSION

The results primarily backed the cumulative advantage/disadvantage life course framework, while finding some indication for age as a leveller hypothesis. Variability in patterns of dynamic co-action among the health outcomes depicts ageing as a naturally variable process of interconnected changes. Life course evidence for the ways socio-economic forces are differentially linked to distinct developmental profiles of ageing is provided.

Social inequalities in the burden of care: a dyadic analysis in the caregiving partners of persons with a physical disability

BACKGROUND

Socioeconomic position (SEP) is an important contextual factor in the Stress Process Model of caregiving. However, the basic assumption that low SEP is associated with greater caregiver burden has so far lacked empirical support. The objective of this study was to investigate social inequalities in the caregiver burden among caregiving partners of persons with a physical disability, i.e., spinal cord injury (SCI), applying a dyadic approach. More specifically, we investigated 1) the association of the caregivers' SEP with caregiver burden ('actor effect'); 2) the association of the care-receivers' SEP with caregiver burden ('partner effect'), and 3) potential mediators of the association between SEP and caregiver burden.

METHODS

Cross-sectional survey data from 118 couples of persons with SCI and their partners living in Switzerland was used. We firstly employed logistic regression to investigate the actor and partner effects of SEP on objective (hours of caregiving) and subjective caregiver burden (Zarit Burden Interview). We additionally used structural equation modelling to explore whether unfulfilled support needs, psychosocial resources and the care-receivers health status mediated the association between SEP and caregiver burden. SEP was operationalized by household income, education, subjective social position, financial strain and home ownership.

RESULTS

We observed a consistent trend towards higher objective and subjective burden in lower SEP groups. Caregivers with higher subjective social positon and home ownership indicated lower subjective burden, and caregivers with higher education and absence of financial strain reported lower objective burden. Further evidence suggested a partner effect of SEP on caregiver burden, whereby objective caregiver burden was reduced in couples where the care-receiver had a higher educational level. The negative association between SEP and subjective burden was partially mediated by the unfulfilled support needs and deprived psychological resources of the caregiver, and the poor health status of the care-receiver. Similar mediation effects were not supported for objective burden.

CONCLUSIONS

Our study, in the context of SCI, provides support for the contextual role of SEP in the Stress Process Model of caregiving. To reduce subjective caregiver burden, policy programs may target the strengthening of psychosocial resources, or the improvement of access to support services for caregivers with low SEP.

Potential for non-combustible nicotine products to reduce socioeconomic inequalities in smoking: a systematic review and synthesis of best available evidence

BACKGROUND

While some experts have emphasised the potential for e-cigarettes to facilitate cessation among smokers with low socioeconomic status (SES), there is limited evidence of their likely equity impact. We assessed the potential for electronic cigarettes and other non-combustible nicotine-containing products (NCNPs) to reduce inequalities in smoking by systematically reviewing evidence on their use by SES in countries at stage IV of the cigarette epidemic.

METHODS

Ten electronic databases were searched in February 2017 using terms relating to e-cigarettes, smokeless tobacco and nicotine replacement therapy (NRT); and SES. We included studies published since 1980 that were available in English and examined product use by SES indicators such as income and education. Data synthesis was based on those studies judged to be of medium- to high-quality using guidelines adapted from the Critical Appraisal Skills Programme.

RESULTS

We identified 54 studies describing NCNP use by SES across 12 countries, of which 27 were judged of sufficient quality to include in data synthesis. We found mixed patterns of e-cigarette current use by SES, with evidence of higher use among low-income adults but unclear or mixed findings by education and occupation. In contrast, smokeless tobacco current use was consistently higher among low SES adults. There was very limited evidence on the SES distribution of NRT in adults and of all NCNPs in young people.

CONCLUSIONS

The only NCNP for which there are clear patterns of use by SES is smokeless tobacco, where prevalence is higher among low SES groups. While this suggests a potentially positive impact on inequalities in smoking (if NCNP use displaces smoked tobacco use), this has not been seen in practice. These findings do not support the suggestion that e-cigarettes have the potential to reduce social inequalities in smoking, since i) current evidence does not show a clear trend of higher e-cigarette use in population groups with higher tobacco consumption, and ii) the experience of smokeless tobacco suggests that - even where NCNP use is higher among low SES groups - this does not necessarily replace smoked tobacco use in these groups.

Socioeconomic and ethnic differences in children's vigorous intensity physical activity: a cross-sectional analysis of the UK Millennium Cohort Study

OBJECTIVE

To investigate if daily vigorous physical activity (VPA), adjusted for minutes of moderate physical activity (MPA) performed, differs by socioeconomic position or ethnicity in a large sample of UK children with objectively measured physical activity.

DESIGN

Nationally representative prospective cohort study.

SETTING

UK children born between 2000 and 2002.

PARTICIPANTS

5172 children aged 7-8 with valid accelerometer data for ≥10 hour on ≥3 days, including 1 weekend day.

MAIN OUTCOME MEASURES

Time spent in VPA (>3841 counts per min).

EXPLANATORY MEASURES

Maternal education, annual household Organisation for Economic Co-Operation and Development equivalised income, ethnicity.

RESULTS

Multivariable linear regression models fitted to explore differences in average daily minutes of VPA (adjusted for MPA, mean accelerometer wear time, season of measurement, age and sex), revealed significantly higher amounts of VPA accumulated as a child's socioeconomic position increased (highest vs lowest level of maternal education: β: 2.96, p: 0.00; annual household equivalised income: β: 0.58, p: 0.00, per £10 000 annual increase). Additionally, children from certain minority ethnicities (Bangladeshi and Pakistani: β: -3.34, p: 0.00; other ethnic groups: β:-2.27, p: 0.02) accrued less daily VPA compared with their white British counterparts.

CONCLUSIONS

The socioeconomic and ethnic patterning of vigorous activity observed in this study mirrors parallel inequalities in rates of childhood obesity. Given the stronger association of VPA with adiposity than of MPA, intensity specific differences may be contributing to widening inequalities in obesity. Accordingly, these findings suggest that the current global focus on overall moderate-to-vigorous intensity activity may mask important behavioural inequalities.

Socioeconomic inequalities in survival of children with acute lymphoblastic leukemia insured by social security in Mexico: a study of the 2007-2009 cohorts

BACKGROUND

Although acute lymphoblastic leukemia (ALL) 5 years survival in minors has reached 90%, socioeconomic differences have been reported among and within countries. Within countries, the difference has been related to the socioeconomic status of the parents, even in the context of public health services with universal coverage. In Mexico, differences in the mortality of children with cancer have been reported among sociodemographic zones. The Instituto Mexicano del Seguro Social (IMSS), the country's main social security institution, has reported socioeconomic differences in life expectancy within its affiliated population. Here, the socioeconomic inequalities in the survival of children (< 15 years old) enrolled in the IMSS were analyzed.

METHODS

Five-year survival data were analyzed in cohorts of patients diagnosed with ALL during the period 2007-2009 in the two IMSS networks of medical services that serve 7 states of the central region of Mexico. A Cox proportional risk model was developed and adjusted for the socioeconomic characteristics of family, community of residence and for the clinical characteristics of the children. The slope of socioeconomic inequality of the probability of dying within five years after the diagnosis of ALL was estimated.

RESULTS

For the 294 patients studied, the 5 years survival rate was 53.7%; the median survival was 4.06 years (4.9 years for standard-risk diagnosis; 2.5 years for high-risk diagnosis). The attrition rate was 12%. The Cox model showed that children who had been IMSS-insured for less than half their lives had more than double the risk of dying than those who had been insured for their entire lives.

CONCLUSIONS

We did not find evidence of socioeconomic inequalities in the survival of children with ALL associated with family income, educational and occupational level of parents. However, we found a relevant gradient related social security protection: the longer children's life insured by social security, the higher their probability of surviving ALL was. These results add evidence of the effectiveness of social security, as a mechanism of wealth redistribution and a promoter of social mobility. Extending these social security benefits to the entire Mexican population could promote better health outcomes.