Are stress-related pathways of social status differentiation more important determinants of health inequities in countries with higher levels of income inequality?

We explored socioeconomic gradients in self-rated overall health (SROH) using indicators of materialist (educational attainment and perceived income adequacy) and psychosocial perspectives (subjective social status (SSS)) among adults living in countries with varying levels of income inequality, and the importance of psychosocial stress in mediating these associations. If psychosocial processes at the individual and societal levels correspond, associations between SSS and SROH should be higher among adults in countries with higher income inequality, and psychosocial stress should be a more important mediator of these associations. We used multigroup structural equation models to analyse cross-sectional data from the International Food Policy Study of adults (n = 22,824) in Australia, Canada, Mexico, the UK and the United States. Associations between SSS and SROH were not higher in more unequal countries, nor was psychosocial stress a more important mediator of these associations. Inequities in SROH in more unequal countries may not predominantly reflect stress-related pathways of social status differentiation.

Healthy food prescription incentive programme for adults with type 2 diabetes who are experiencing food insecurity: protocol for a randomised controlled trial, modelling and implementation studies.

INTRODUCTION: The high cost of many healthy foods poses a challenge to maintaining optimal blood glucose levels for adults with type 2 diabetes mellitus who are experiencing food insecurity, leading to diabetes complications and excess acute care usage and costs. Healthy food prescription programmes may reduce food insecurity and support patients to improve their diet quality, prevent diabetes complications and avoid acute care use. We will use a type 2 hybrid-effectiveness design to examine the reach, effectiveness, adoption, implementation and maintenance (RE-AIM) of a healthy food prescription incentive programme for adults experiencing food insecurity and persistent hyperglycaemia. A randomised controlled trial (RCT) will investigate programme effectiveness via impact on glycosylated haemoglobin (primary outcome), food insecurity, diet quality and other clinical and patient-reported outcomes. A modelling study will estimate longer-term programme effectiveness in reducing diabetes-related complications, resource use and costs. An implementation study will examine all RE-AIM domains to understand determinants of effective implementation and reasons behind programme successes and failures. METHODS AND ANALYSIS: 594 adults who are experiencing food insecurity and persistent hyperglycaemia will be randomised to a healthy food prescription incentive (n=297) or a healthy food prescription comparison group (n=297). Both groups will receive a healthy food prescription. The incentive group will additionally receive a weekly incentive (CDN$10.50/household member) to purchase healthy foods in supermarkets for 6 months. Outcomes will be assessed at baseline and follow-up (6 months) in the RCT and analysed using mixed-effects regression. Longer-term outcomes will be modelled using the UK Prospective Diabetes Study outcomes simulation model-2. Implementation processes and outcomes will be continuously measured via quantitative and qualitative data. ETHICS AND DISSEMINATION: Ethical approval was obtained from the University of Calgary and the University of Alberta. Findings will be disseminated through reports, lay summaries, policy briefs, academic publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT04725630. PROTOCOL VERSION: Version 1.1; February 2022.

Stress-Related Poor Diet Quality Does Not Explain Socioeconomic Inequities in Health: A Structural Equation Mediation Analysis of Gender-Specific Pathways.

BACKGROUND: Psychosocial stress and diet quality individually mediate associations between socioeconomic position (SEP) and health; however, it is not known whether they jointly mediate these associations. This is an important question because stress-related unhealthy eating is often invoked as an explanation for diet-related health inequities, particularly among women, seemingly with no empirical justification. OBJECTIVE: This study examined whether psychosocial stress and diet quality jointly mediated associations between SEP and self-rated health in women and men. DESIGN: Multiple mediating pathways were modeled using data from the cross-sectional International Food Policy Study. PARTICIPANTS AND SETTING: Data were collected from 5,645 adults (aged 18 years or older) in Canada during 2018 and 2019. MAIN OUTCOME MEASURES: Participants reported SEP using indicators of materialist (educational attainment and perceived income adequacy) and psychosocial pathways (subjective social status), along with psychosocial stress, dietary intake (to assess overall diet quality via Healthy Eating Index-2015 scores), and self-rated health. STATISTICAL ANALYSES PERFORMED: Structural equation modeling modeled pathways linking SEP (ie, educational attainment, perceived income adequacy, and subjective social status) with self-rated health mediated by psychosocial stress and diet quality, stratified by gender. RESULTS: There was no evidence that psychosocial stress and diet quality jointly mediated associations between SEP and self-rated health in women or men. Diet quality mediated associations between educational attainment and self-rated health in women and men, with some evidence that it mediated associations between subjective social status and self-rated health in men (P = 0.051). Psychosocial stress mediated associations between perceived income adequacy and self-rated health in women and men, and between subjective social status and self-rated health in women. CONCLUSIONS: Although often invoked as an explanation for diet-related health inequities, stress-related poor diet quality did not mediate associations between SEP and self-rated health in women or men. Psychosocial stress and diet quality individually mediated some of these associations, with some differences by gender.

Socioeconomic inequities in diet quality among a nationally representative sample of adults living in Canada: an analysis of trends between 2004 and 2015.

BACKGROUND: Socioeconomic inequities in diet quality are stable or widening in the United States; however, these trends have not been well characterized in other nations. Moreover, purpose-developed indices of inequities that can provide a more comprehensive and precise perspective of trends in absolute and relative dietary gaps and gradients using multiple indicators of socioeconomic position (SEP) have not yet been used, and can inform strategies to narrow dietary inequities. OBJECTIVES: We quantified nationally representative trends in absolute and relative gaps and gradients in diet quality between 2004 and 2015 according to 3 indicators of SEP among adults in Canada. METHODS: Adults (≥18 y old) who participated in the nationally representative, cross-sectional Canadian Community Health Survey-Nutrition in 2004 (n = 20,880) or 2015 (n = 13,970) were included. SEP was classified using household income (quintiles), education (5 categories), and neighborhood deprivation (quintiles). Dietary intake data from 24-h recalls were used to derive Healthy Eating Index-2015 (HEI-2015) scores. Dietary inequities were quantified using absolute and relative gaps (between the most and least disadvantaged) and absolute [Slope Index of Inequality (SII)] and relative gradients (Relative Index of Inequality). Overall and sex-stratified multivariable linear regression and generalized linear models examined trends in HEI-2015 scores between 2004 and 2015. RESULTS: Mean HEI-2015 scores improved from 55.3 to 59.0 (maximum: 100); however, these trends were not consistently equitable. Whereas inequities in HEI-2015 scores were stable in the total population and in females, the absolute gap [from 1.60 (95% CI: 0.09, 3.10) to 4.27 (95% CI: 2.20, 6.34)] and gradient [from SII = 2.09 (95% CI: 0.45, 3.73) to SII = 4.84 (95% CI: 2.49, 7.20)] in HEI-2015 scores for household income, and the absolute gradient for education [from SII = 8.06 (95% CI: 6.41, 9.71) to SII = 10.52 (95% CI: 8.73, 12.31)], increased in males. CONCLUSIONS: Absolute and relative gaps and gradients in overall diet quality remained stable or widened between 2004 and 2015 among adults in Canada.

Trends in Socioeconomic Inequities in Diet Quality between 2004 and 2015 among a Nationally Representative Sample of Children in Canada.

BACKGROUND: Dietary inequities in childhood may shape dietary and health inequities across the life course. Quantifying the magnitude and direction of trends in absolute and relative gaps and gradients in diet quality according to multiple indicators of socioeconomic position (SEP) can inform strategies to narrow these inequities. OBJECTIVES: We examined trends in absolute and relative gaps and gradients in diet quality between 2004 and 2015 according to 3 indicators of SEP among a nationally representative sample of children in Canada. METHODS: Data from children (aged 2-17 y; n = 18,670) who participated in the cross-sectional Canadian Community Health Survey-Nutrition in 2004 or 2015 were analyzed. SEP was based on total household income, household educational attainment, and neighborhood deprivation. Dietary intake data from 1 interviewer-administered 24-h dietary recall were used to derive a Healthy Eating Index-2015 (HEI-2015) score for each participant as a measure of diet quality. Inequities in diet quality were quantified using 4 indices: absolute and relative gaps (between highest and lowest SEP) and absolute (Slope Index of Inequality) and relative gradients (Relative Index of Inequality). Overall and age-stratified multivariable linear regression and generalized linear models examined trends in HEI-2015 scores between 2004 and 2015. RESULTS: Although mean HEI-2015 total scores improved from 52.3 to 57.3 (maximum 100 points; P < 0.001), absolute and relative gaps and gradients in diet quality remained mostly stable for all 3 SEP indicators. However, among children aged 6-11 y, absolute and relative gradients in diet quality according to household educational attainment and neighborhood deprivation widened. CONCLUSIONS: The diet quality of children in Canada was poor and inequitably patterned in 2004 and 2015. Although mean diet quality improved between 2004 and 2015, absolute and relative gaps and gradients in diet quality persisted, with some evidence of widening absolute and relative gradients among 6- to 11-y-olds.

Quantifying the contribution of modifiable risk factors to socio-economic inequities in cancer morbidity and mortality: a nationally representative population-based cohort study.

BACKGROUND: Compared with those with a higher socio-economic position (SEP), individuals with a lower SEP have higher cancer morbidity and mortality. However, the contribution of modifiable risk factors to these inequities is not known. This study aimed to quantify the mediating effects of modifiable risk factors to associations between SEP and cancer morbidity and mortality. METHODS: This study used a prospective observational cohort design. We combined eight cycles of the Canadian Community Health Survey (2000/2001-2011) as baseline data to identify a cohort of adults (≥35 years) without cancer at the time of survey administration (n = 309 800). The cohort was linked to the Discharge Abstract Database and the Canadian Mortality Database for cancer morbidity and mortality ascertainment. Individuals were followed from the date they completed the Canadian Community Health Survey until 31 March 2013. Dates of individual first hospitalizations for cancer and deaths due to cancer were captured during this time period. SEP was operationalized using a latent variable combining measures of education and household income. Self-reported modifiable risk factors, including smoking, excess alcohol consumption, low fruit-and-vegetable intake, physical inactivity and obesity, were considered as potential mediators. Generalized structural equation modelling was used to estimate the mediating effects of modifiable risk factors in associations between low SEP and cancer morbidity and mortality in the total population and stratified by sex. RESULTS: Modifiable risk factors together explained 45.6% of associations between low SEP and overall cancer morbidity and mortality. Smoking was the most important mediator in the total population and for males, accounting for 15.5% and 40.2% of the total effect, respectively. For females, obesity was the most important mediator. CONCLUSIONS: Modifiable risk factors are important mediators of socio-economic inequities in cancer morbidity and mortality. Nevertheless, more than half of the variance in these associations remained unexplained. Midstream interventions that target modifiable risk factors may help to alleviate inequities in cancer risk in the short term. However, ultimately, upstream interventions that target structural determinants of health are needed to reduce overall socio-economic inequities in cancer morbidity and mortality.

National and sub-national burden of chronic diseases attributable to lifestyle risk factors in Iran 1990 - 2013; study protocol.

BACKGROUND: Non-communicable diseases, as the major public health problem, are caused by different risk factors. The main leading lifestyle risk factors for most diseases burden in Iran are unhealthy diet, physical inactivity, and smoking. The aim of this study is to provide data collection and methodology processes for estimating the trends of exposures to the selected lifestyle risk factors and their attributed burden at national and sub-national levels. METHODS: Systematic review will be performed through PubMed/MEDLINE, Scopus and ISI/Web of Science as well as Iranian databases such as IranMedex, Irandoc and Scientific Information Database (SID). In addition, hand searching of unpublished data sources will be used to identify relevant population-based studies. The searched studies will be included only if it is reasonably population-based and representative, and exposure data has been reported or could be plausibly obtained from the study. For risk factors with no surveys identified, other sources of potential data will be considered. The target population is healthy Iranian adult population living within Iran from 1990 to 2013. Other data sources include national censuses, national registration systems, and national and sub-national surveys. Spatio-temporal Bayesian hierarchical model and Bayesian multilevel autoregressive model will be used to overcome the problem of data gaps in provinces, and in some age or sex groups or in urban/rural areas. The problem of misaligned areal units will be also addressed in these models. CONCLUSION: National and sub-national assessment of major lifestyle risk factors such as unhealthy diet, physical inactivity, and smoking is necessary for priority setting and policy making in different regions of Iran.