The Population Education Transition Curve: Education Gradients Across Population Exposure to New Health Risks

The changing relationship between bodyweight and longevity in high- and low-income countries

Standard measures of bodyweight (overweight and obese, for example) fail to reflect differences across populations and technological progress over time. This paper builds on the pioneering work of Hans Waaler (1984) and Robert Fogel (1994) to empirically estimate how the relationship between body mass index (BMI) and longevity varies across high-, middle-, and low-income countries. Importantly, we show that these differences are so profound that the share of national populations above mortality-minimizing bodyweight is not clearly greater in countries with higher overweight and obesity rates (as traditionally defined)-and in fact, relative to current standards, a larger share of low-income countries' populations can be unhealthily heavy.

Effects of education on adult mortality: a global systematic review and meta-analysis

BACKGROUND

The positive effect of education on reducing all-cause adult mortality is known; however, the relative magnitude of this effect has not been systematically quantified. The aim of our study was to estimate the reduction in all-cause adult mortality associated with each year of schooling at a global level.

METHODS

In this systematic review and meta-analysis, we assessed the effect of education on all-cause adult mortality. We searched PubMed, Web of Science, Scopus, Embase, Global Health (CAB), EconLit, and Sociology Source Ultimate databases from Jan 1, 1980, to May 31, 2023. Reviewers (LD, TM, HDV, CW, IG, AG, CD, DS, KB, KE, and AA) assessed each record for individual-level data on educational attainment and mortality. Data were extracted by a single reviewer into a standard template from the Global Burden of Diseases, Injuries, and Risk Factors Study. We excluded studies that relied on case-crossover or ecological study designs to reduce the risk of bias from unlinked data and studies that did not report key measures of interest (all-cause adult mortality). Mixed-effects meta-regression models were implemented to address heterogeneity in referent and exposure measures among studies and to adjust for study-level covariates. This study was registered with PROSPERO (CRD42020183923).

FINDINGS

17 094 unique records were identified, 603 of which were eligible for analysis and included data from 70 locations in 59 countries, producing a final dataset of 10 355 observations. Education showed a dose-response relationship with all-cause adult mortality, with an average reduction in mortality risk of 1·9% (95% uncertainty interval 1·8-2·0) per additional year of education. The effect was greater in younger age groups than in older age groups, with an average reduction in mortality risk of 2·9% (2·8-3·0) associated with each additional year of education for adults aged 18-49 years, compared with a 0·8% (0·6-1·0) reduction for adults older than 70 years. We found no differential effect of education on all-cause mortality by sex or Socio-demographic Index level. We identified publication bias (p<0·0001) and identified and reported estimates of between-study heterogeneity.

INTERPRETATION

To our knowledge, this is the first systematic review and meta-analysis to quantify the importance of years of schooling in reducing adult mortality, the benefits of which extend into older age and are substantial across sexes and economic contexts. This work provides compelling evidence of the importance of education in improving life expectancy and supports calls for increased investment in education as a crucial pathway for reducing global inequities in mortality.

FUNDING

Research Council of Norway and the Bill & Melinda Gates Foundation.

Double burden of malnutrition and its associated factors among women in low and middle income countries: findings from 52 nationally representative data

BACKGROUND

Double burden of malnutrition (DBM) is an emerging global public health problem. The United Nations member states adopted eradicating all forms of malnutrition as an integral component of the global agenda. However, there is evidence of a high burden of undernutrition among women and rising rates of overweight and obesity, especially in low and middle income countries (LMICs). Therefore, this study aimed to investigate the prevalence and associated factors of underweight, overweight, and obesity among women of reproductive age in LMICs.

METHODS

Data for the study were drawn from a recent 52 Demographic and Health Surveys (DHS) conducted in LMICS. We included a sample of 1,099,187 women of reproductive age. A multilevel multinomial logistic regression model was used to identify factors associated with DBM. Adjusted relative risk ratio (RRR) with a 95% Confidence Interval (CI) was reported to show an association.

RESULTS

The prevalence of underweight, overweight, and obesity in LMICs among women of reproductive age was 15.2% (95% CI: 15.1-15.3), 19.0% (95% CI: 18.9- 19.1), and 9.1% (95% CI: 9.0-9.2), respectively. This study found that women aged 24-34 years, aged ≥ 35 years, with primary, secondary, and above educational level, from wealthy households, using modern contraceptives, exposed to media (radio and television), and with high parity (more than one birth) were more likely to have overweight and obesity and less likely to have underweight. Moreover, the risk of having obesity (RRR = 0.59; 95% CI = 0.58-0.60 and overweight (RRR = 0.78; 95% CI = 0.77-0.79) were lower among rural women, while the risk of being underweight was (RRR = 1.13; 95% CI = 1.11-1.15) higher among rural women compared to urban women.

CONCLUSION

The prevalence of underweight, overweight, and obesity was high among women of reproductive age in LMICs. Underweight, overweight, and obesity are influenced by sociodemographic, socioeconomic, and behavioral-related factors. This study shows that, in order to achieve Sustainable Development Goal 2, a multifaceted intervention approach should be considered to prevent both forms of malnutrition in women of reproductive age. This can be achieved by raising awareness and promoting healthy behaviors such as healthy eating and physical activity, especially among educated women, women from wealthy households, and women exposed to the media.

Shifting educational gradients in body mass index trajectories of Indonesians: an age period cohort analysis

Background

Globally, the number of obese adults has increased rapidly in many developing countries. The links between increased educational attainment and lower risks of overweight/obesity have been studied in a number of high-income contexts. However, educational attainment can have a different association with obesity at different levels of economic development and different stages of the nutritional transition, and these associations may vary by period and cohort. This study aims to provide evidence on the shifting of educational gradients in overweight/obesity in Indonesia, a low middle income country.

Methods

Using five waves of Indonesian Family Life Survey (IFLS), this study examines the Body Mass Index (BMI) trajectories of 14,810 individuals from 1993 to 2014. This study analyses how educational gradients in BMI have shifted over time and across cohorts using a hierarchical age-period-cohort (HAPC) model to account for the effects of age and the changes in historical periods (social and environmental contexts).

Results

In older generations, higher educational attainment is associated with higher BMI, but the gap between educational groups shrinks in more recently-born cohorts. The BMI of lower educational groups is catching up with that of the tertiary educated, leading to an increased risk of overweight/obesity among low educated individuals. Having tertiary education lowers the risk of weight gain (-0.04 point) among recently-born cohort of women, but it still increases the risk (+ 0.04 point) for men.

Conclusion

Changes in access to education and the ongoing nutritional transition in Indonesia are leading to a shifting of educational gradients in overweight/obesity over time. The rising trends in BMI among low-educated and younger individuals are of substantial concern for Indonesian public health due to their implications for the risk of communicable and non-communicable diseases in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13379-3.

Prevalence and socio-demographic associations of diet and physical activity risk-factors for cardiovascular disease in Bo, Sierra Leone

BACKGROUND

Little is known about modifiable dietary and physical activity risk factors for cardiovascular diseases (CVDs) in Sierra Leone. This information is critical to the development of health improvement interventions to reduce the prevalence of these diseases. This cross-sectional study investigated the prevalence and socio-demographic correlates of dietary and physical activity risk behaviours amongst adults in Bo District, Sierra Leone.

METHODS

Adults aged 40+ were recruited from 10 urban and 30 rural sub-districts in Bo. We examined risk factors including: ≤150 min of moderate or vigorous-intensity physical activity (MVPA) weekly, physical inactivity for ≥3 h daily, ≤5 daily portions of fruit and vegetables, and salt consumption (during cooking, at the table, and in salty snacks). We used logistic regression to investigate the relationship between these outcomes and participants' socio-demographic characteristics.

RESULTS

1978 eligible participants (39.1% urban, 55.6% female) were included in the study. The prevalence of behavioural risk factors was 83.6% for ≤5 daily portions of fruit and vegetables; 41.4 and 91.6% for adding salt at the table or during cooking, respectively and 31.1% for eating salty snacks; 26.1% for MVPA ≤150 min weekly, and 45.6% for being physically inactive ≥3 h daily. Most MVPA was accrued at work (nearly 24 h weekly). Multivariable analysis showed that urban individuals were more likely than rural individuals to consume ≤5 daily portions of fruit and vegetables (Odds Ratio (OR) 1.09, 95% Confidence Interval (1.04-1.15)), add salt at the Table (OR 1.88 (1.82-1.94)), eat salty snacks (OR 2.00 (1.94-2.07)), and do MVPA ≤150 min weekly (OR 1.16 (1.12-1.21)). Male individuals were more likely to add salt at the Table (OR 1.23 (1.20-1.27)) or consume salty snacks (OR 1.35 (1.31-1.40)) than female individuals but were less likely to report the other behavioural risk-factors examined. Generally, people in lower wealth quintiles had lower odds of each risk factor than those in the higher wealth quintiles.

CONCLUSION

Dietary risk factors for CVD are highly prevalent, particularly among urban residents, of Bo District, Sierra Leone. Our findings highlight that forthcoming policies in Sierra Leone need to consider modifiable risk factors for CVD in the context of urbanisation.

Medical innovations can reduce social inequalities in health: an analysis of blood pressure and medication in the HUNT study

This paper examines whether the use of blood pressure medication has an influence on social inequalities in blood pressure levels. In Norway, cardiovascular disease has for decades been associated with high mortality and social inequalities. High blood pressure is an important risk factor in this aspect, and prescription drugs have been established as a standard treatment of hypertension. We have seen population blood pressure levels fall, blood pressure inequality levels remaining stabile, and medication use increase. The paper uses panel data from the Nord-Trøndelag Health Study linked with registry data on education and income. Results from fixed effects regression analyses indicate that blood pressure medication overall has a levelling effect. The traditional social gradient is mainly found among non-users of medication. With blood pressure medication being plausibly at a late stage of its diffusion, these findings give some support to the hierarchical diffusion model, while they also imply the need for equal access to sufficient blood pressure treatment.

Objective and subjective childhood socioeconomic disadvantage and incident depression in adulthood: a longitudinal analysis in the Sister Study

Understanding of the role of objective versus subjective childhood socioeconomic disadvantage (SD) in depression onset in adulthood among women, independent of later life SD, and across birth cohorts, is limited. We examined the association between objective (i.e., household education level) and subjective (i.e., rank of family income and report of not enough food to eat) SD during childhood and diagnosis of clinical depression after age 30 among 47,055 women in the Sister Study. We used Cox proportional hazard models adjusting for women's race/ethnicity, childhood household composition, mother's age at her birth adulthood educational attainment, and calendar year of birth. Analyses were repeated stratified by 10-year birth group. A total of 8036 (17.1%) women were diagnosed with clinical depression over a mean follow-up of 24.0 (± 9.9) years. Those reporting being poor (versus well-off) or not having enough food to eat in childhood had a 1.28 (95% confidence interval (CI) 1.13, 1.44) and 1.30 (95% CI 1.21, 1.41) times higher rate of depression diagnosis, respectively, with consistent associations observed across birth year groups. An inverse association between low household education level and incident depression was observed at baseline (i.e., age 30) becoming positive over time in the total sample but only among women born between 1935-1954 in analyses stratified by 10-year birth group. Our findings suggest that subjective SD in childhood is a largely consistent predictor of depression onset among women in adulthood whereas the effects of household education level in childhood may vary across women born into different birth cohorts, and for some, across the lifecourse.

Achieved educational attainment, inherited genetic endowment for education, and obesity

This study investigates two sources of education effects on obesity - achieved educational attainment and inherited genetic endowment for education. In doing so, we accomplish two goals. First, we assess the role of genetic confounding in the association between education and health. Second, we consider the heterogeneity in the extent to which genetic potential for education is realized, and we examine its impact on obesity. Data come from the National Longitudinal Study of Adolescent to Adult Health. Using a polygenic score approach, we find that, net of genetic confounding, holding a college degree is associated with a lower likelihood of obesity. Moreover, among individuals who hold a college degree, those with a high education polygenic score (a greater genetic propensity to succeed in education) are less likely to be obese than those with a relatively low education polygenic score. However, when individuals with a high education polygenic score do not have a college degree, their risk of obesity is similar to that of non-college-educated individuals with a low education polygenic score, suggesting that the effect of genetic endowment for education on obesity is conditional on college education.

Educational Disparities in COVID-19 Prevention in China: The Role of Contextual Danger, Perceived Risk, and Interventional Context

Despite the social disparities in COVID-19 infection, little is known about factors influencing social disparities in preventive behaviors during the pandemic. This study examined how educational disparities in mask-wearing, handwashing, and limiting public outings might be contingent upon three factors: contextual cue of danger, perceived risk of local outbreak, and interventional context with different levels of intensity (i.e, Wuhan vs. other areas). Data were obtained from a telephone survey of 3327 adults, who were recruited through a random-digit-dial method to be representative of all cell phone users in China. Interviews were conducted from 28 April to 26 May 2020. Stratified multiple regression models showed that educational disparities in all three behaviors were only consistently observed among people exposed to context cues of danger, with an enhanced sense of risk of a local outbreak, or in areas other than Wuhan. College education seems to make a difference in handwashing regardless of contextual cues of danger or perception of risk. The findings suggested that, in the process of an epidemic, emerging threats in one's immediate environment or raised awareness of risks are important conditions triggering educational disparities in prevention. However, effective public health interventions could potentially reduce such disparities.

Explaining the Education-Health Gradient in Preventing STIs in Andean Peru: Cognitive Executive Functioning, Awareness and Health Knowledge

CONTEXT

Little is known about the pathways mediating the relationship between education and health. It is widely assumed that formal schooling leads to awareness of health risks (e.g., STIs) and, in turn, to adoption of preventive behavior (e.g., condom use); however, evidence supporting this mechanism has been limited.

METHODS

Survey data were collected in 2010 from a sample of 247 adults aged 30-62 living in an isolated Andean district of Peru; these individuals had widely varying exposure to schooling, and their community had recently experienced elevated risks of STIs. Structural equation modeling was used to estimate the degree to which schooling is associated with cognitive resources, STI awareness and sexual health knowledge, and how these jointly are associated with ever-use of condoms.

RESULTS

Thirty-two percent of respondents reported ever-use of condoms. One additional year of schooling was associated with a 2.7-percentage-point increase in the probability of condom use, after adjustment for covariates. The pathway between education and condom use was mediated by cognitive executive functioning (CEF) skills (0.26 standard deviations), STI awareness (0.09) and sexual health knowledge (0.10); CEF skills were associated with condom use both directly and indirectly, through STI awareness and sexual health knowledge, and accounted for two-thirds of the education-condom use gradient.

CONCLUSIONS

The relationship between education and STI prevention may be more complex than is often assumed and is mediated by CEF skills, STI awareness and sexual health knowledge. Studies should examine whether STI prevention interventions are more effective if they enhance cognitive skills used to translate information into protective behaviors.

Why does the importance of education for health differ across the United States?

The positive association between educational attainment and adult health ("the gradient") is stronger in some areas of the United States than in others. Explanations for the geographic pattern have not been rigorously investigated. Grounded in a contextual and life course perspective, this study assesses childhood circumstances (e.g., childhood health, compulsory schooling laws) and adult circumstances (e.g., wealth, lifestyles, economic policies) as potential explanations. Using data on US-born adults aged 50-59 at baseline (N=13,095) and followed for up to 16 years across the 1998-2014 waves of the Health and Retirement Study, this study examined how and why educational gradients in morbidity, functioning, and mortality vary across nine U.S. regions. The findings indicate that the gradient is stronger in some areas than others partly because of geographic differences in childhood socioeconomic conditions and health, but mostly because of geographic differences in adult circumstances such as wealth, lifestyles, and economic and tobacco policies.

Does schooling protect sexual health? The association between three measures of education and STIs among adolescents in Malawi

While multiple studies have documented shifting educational gradients in HIV prevalence, less attention has been given to the effect of school participation and academic skills on infection during adolescence. Using the Malawi Schooling and Adolescent Study, a longitudinal survey that followed 2,649 young people aged 14-17 at baseline from 2007 to 2013, we estimate the effect of three education variables: school enrolment, grade attainment, and academic skills-numeracy and Chichewa literacy-on herpes simplex virus type 2 (HSV-2) and HIV incidence using interval-censored survival analysis. We find that grade attainment is significantly associated with lower rates of both HSV-2 and HIV among girls, and is negatively associated with HSV-2 but not HIV among boys. School enrolment and academic skills are not significantly associated with sexually transmitted infections (STIs) for boys or girls in our final models. Efforts to encourage school progression in high-prevalence settings in sub-Saharan Africa could well reduce, or at least postpone, acquisition of STIs.

Moving Upstream: The Effect of Tobacco Clean Air Restrictions on Educational Inequalities in Smoking Among Young Adults

Education affords a range of direct and indirect benefits that promote longer and healthier lives and stratify health lifestyles. We use tobacco clean air policies to examine whether policies that apply universally-interventions that bypass individuals' unequal access and ability to employ flexible resources to avoid health hazards-have an effect on educational inequalities in health behaviors. We test theoretically informed but competing hypotheses that these policies either amplify or attenuate the association between education and smoking behavior. Our results provide evidence that interventions that move upstream to apply universally regardless of individual educational attainment-here, tobacco clean air policies-are particularly effective among young adults with the lowest levels of parental or individual educational attainment. These findings provide important evidence that upstream approaches may disrupt persistent educational inequalities in health behaviors. In doing so, they provide opportunities to intervene on behaviors in early adulthood that contribute to disparities in morbidity and mortality later in the life course. These findings also help assuage concerns that tobacco clean air policies increase educational inequalities in smoking by stigmatizing those with the fewest resources.

Educational expansion and health disparities in Ethiopia, 2005-2016

Research shows that basic education improves population health, yet it remains unclear whether the expansion of primary education decreases health disparities. In this paper, I assess whether disparities in healthcare utilization decreased in conjunction with educational expansion among women of reproductive age in Ethiopia. Healthcare utilization rates in low-resource countries are often confounded with simultaneous developments in education and access to basic healthcare. Using decomposition of rates, I first disentangle the changes in health disparities induced by educational expansion from the overall increase in healthcare utilization. Then, I use the Blinder-Oaxaca decomposition method to investigate the determinants of disparities in healthcare utilization and how these determinants changed over a 10-year period as primary education became more prevalent. Overall, disparities in healthcare utilization in Ethiopia decreased over time, yet the association between educational expansion and health disparities varies by region. Literacy explains much of the disparities in healthcare utilization, yet it loses significance over time as primary education becomes widespread. Economic factors remain persistent sources of disparities, and non-financial barriers such as the distance to travel and women's ability to travel alone become more significant. Heterogeneity in healthcare utilization across regions has distinct implications for how educational expansion may shift health disparities.

Educational Disparities in Adult Mortality Across U.S. States: How Do They Differ, and Have They Changed Since the Mid-1980s?

Adult mortality varies greatly by educational attainment. Explanations have focused on actions and choices made by individuals, neglecting contextual factors such as economic and policy environments. This study takes an important step toward explaining educational disparities in U.S. adult mortality and their growth since the mid-1980s by examining them across U.S. states. We analyzed data on adults aged 45-89 in the 1985-2011 National Health Interview Survey Linked Mortality File (721,448 adults; 225,592 deaths). We compared educational disparities in mortality in the early twenty-first century (1999-2011) with those of the late twentieth century (1985-1998) for 36 large-sample states, accounting for demographic covariates and birth state. We found that disparities vary considerably by state: in the early twenty-first century, the greater risk of death associated with lacking a high school credential, compared with having completed at least one year of college, ranged from 40 % in Arizona to 104 % in Maryland. The size of the disparities varies across states primarily because mortality associated with low education varies. Between the two periods, higher-educated adult mortality declined to similar levels across most states, but lower-educated adult mortality decreased, increased, or changed little, depending on the state. Consequently, educational disparities in mortality grew over time in many, but not all, states, with growth most common in the South and Midwest. The findings provide new insights into the troubling trends and disparities in U.S. adult mortality.

Educational Disparities in Adult Health: U.S. States as Institutional Actors on the Association

Despite numerous studies on educational disparities in U.S. adult health, explanations for the disparities and their growth over time remain incomplete. We argue that this knowledge gap partly reflects an individualist paradigm in U.S. studies of educational disparities in health. These studies have largely focused on proximal explanations (e.g., individual behaviors) to the neglect of contextual explanations (e.g., economic policies). We draw on contextual theories of health disparities to illustrate how U.S. states, as institutional actors, shape the importance of education for health. Using two nationally-representative datasets and seven health measures for adults aged 45-89, we show that the size of the educational gradient in health varies markedly across states. The size varies because of variation in the health of lower-educated adults. We use state excise taxes on cigarettes to illustrate one way that states shape educational disparities in health. Our findings underscore the necessity of contextualizing these disparities.

The Relationship Between Education and Health: Reducing Disparities Through a Contextual Approach

Adults with higher educational attainment live healthier and longer lives compared with their less educated peers. The disparities are large and widening. We posit that understanding the educational and macrolevel contexts in which this association occurs is key to reducing health disparities and improving population health. In this article, we briefly review and critically assess the current state of research on the relationship between education and health in the United States. We then outline three directions for further research: We extend the conceptualization of education beyond attainment and demonstrate the centrality of the schooling process to health; we highlight the dual role of education as a driver of opportunity but also as a reproducer of inequality; and we explain the central role of specific historical sociopolitical contexts in which the education-health association is embedded. Findings from this research agenda can inform policies and effective interventions to reduce health disparities and improve health for all Americans.