Patterns in Wealth-related Inequalities in 86 Low- and Middle-Income Countries: Global Evidence on the Emergence of Vaccine Hesitancy

INTRODUCTION

Coverage of health interventions usually shows social gradients with higher levels among wealthy than among poor individuals. Owing to the upsurge of vaccine hesitancy in high-income countries, the authors hypothesized that the social gradient may also be changing over time in the low- and middle-income countries and set out to test this hypothesis.

METHODS

In January 2020, surveys conducted from 2010 to 2018 in 86 low- and middle-income countries were analyzed to assess full immunization coverage in children aged 12-23 months. The authors calculated full immunization coverage point estimates and 95% CIs for each country and wealth quintile. To explore wealth-related inequalities, the authors estimated the slope index of inequality and calculated the Pearson correlation coefficient between these values and per capita gross domestic product. Time trends were analyzed in 10 countries with recent evidence of hesitancy.

RESULTS

Pro-poor patterns were defined as significant slope index of inequality values with higher coverage among poor children, and pro-rich patterns were defined as the reverse pattern. A total of 11 countries showed pro-poor patterns in the most recent survey, accounting for 20% of upper middle- and 7% of low-income countries. The correlation between the slope index of inequality and log per capita gross domestic product was -0.38 (p<0.001). Among the 10 countries with recent evidence of hesitancy, 5 showed full immunization coverage declines over time in the wealthiest quintiles, and 4 switched from pro-rich to pro-poor patterns throughout the years.

CONCLUSIONS

Lower full immunization coverage was found among the wealthy than among the poor in 10 countries, especially in the upper middle-income group, consistent with the emergence of vaccine hesitancy.

SUPPLEMENT INFORMATION

This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

Maternal and child health inequalities among migrants: the case of Haiti and the Dominican Republic

Objective.

To assess coverage and inequalities in maternal and child health interventions among Haitians, Haitian migrants in the Dominican Republic and Dominicans.

Methods.

Cross-sectional study using data from nationally representative surveys carried out in Haiti in 2012 and in the Dominican Republic in 2014. Nine indicators were compared: demand for family planning satisfied with modern methods, antenatal care, delivery care (skilled birth attendance), child vaccination (BCG, measles and DPT3), child case management (oral rehydration salts for diarrhea and careseeking for suspected pneumonia), and the composite coverage index. Wealth was measured through an asset-based index, divided into tertiles, and place of residence (urban or rural) was established according to the country definition.

Results.

Haitians showed the lowest coverage for demand for family planning satisfied with modern methods (44.2%), antenatal care (65.3%), skilled birth attendance (39.5%) and careseeking for suspected pneumonia (37.9%), and the highest for oral rehydration salts for diarrhea (52.9%), whereas Haitian migrants had the lowest coverage in DPT3 (44.1%) and oral rehydration salts for diarrhea (38%) and the highest in careseeking for suspected pneumonia (80.7%). Dominicans presented the highest coverage for most indicators, except oral rehydration salts for diarrhea and careseeking for suspected pneumonia. The composite coverage index was 79.2% for Dominicans, 69.0% for Haitian migrants, and 52.6% for Haitians. Socioeconomic inequalities generally had pro-rich and pro-urban pattern in all analyzed groups.

Conclusion.

Haitian migrants presented higher coverage than Haitians, but lower than Dominicans. Both countries should plan actions and policies to increase coverage and address inequalities of maternal health interventions.

SARS-CoV-2 antibody prevalence in Brazil: results from two successive nationwide serological household surveys

BACKGROUND

Population-based data on COVID-19 are essential for guiding policies. There are few such studies, particularly from low or middle-income countries. Brazil is currently a hotspot for COVID-19 globally. We aimed to investigate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody prevalence by city and according to sex, age, ethnicity group, and socioeconomic status, and compare seroprevalence estimates with official statistics on deaths and cases.

METHODS

In this repeated cross-sectional study, we did two seroprevalence surveys in 133 sentinel cities in all Brazilian states. We randomly selected households and randomly selected one individual from all household members. We excluded children younger than 1 year. Presence of antibodies against SARS-CoV-2 was assessed using a lateral flow point-of-care test, the WONDFO SARS-CoV-2 Antibody Test (Wondfo Biotech, Guangzhou, China), using two drops of blood from finger prick samples. This lateral-flow assay detects IgG and IgM isotypes that are specific to the SARS-CoV-2 receptor binding domain of the spike protein. Participants also answered short questionnaires on sociodemographic information (sex, age, education, ethnicity, household size, and household assets) and compliance with physical distancing measures.

FINDINGS

We included 25 025 participants in the first survey (May 14-21) and 31 165 in the second (June 4-7). For the 83 (62%) cities with sample sizes of more than 200 participants in both surveys, the pooled seroprevalence increased from 1·9% (95% CI 1·7-2·1) to 3·1% (2·8-3·4). City-level prevalence ranged from 0% to 25·4% in both surveys. 11 (69%) of 16 cities with prevalence above 2·0% in the first survey were located in a stretch along a 2000 km of the Amazon river in the northern region. In the second survey, we found 34 cities with prevalence above 2·0%, which included the same 11 Amazon cities plus 14 from the northeast region, where prevalence was increasing rapidly. Prevalence levels were lower in the south and centre-west, and intermediate in the southeast, where the highest level was found in Rio de Janeiro (7·5% [4·2-12·2]). In the second survey, prevalence was similar in men and women, but an increased prevalence was observed in participants aged 20-59 years and those living in crowded conditions (4·4% [3·5-5·6] for those living with households with six or more people). Prevalence among Indigenous people was 6·4% (4·1-9·4) compared with 1·4% (1·2-1·7) among White people. Prevalence in the poorest socioeconomic quintile was 3·7% (3·2-4·3) compared with 1·7% (1·4-2·2) in the wealthiest quintile.

INTERPRETATION

Antibody prevalence was highly heterogeneous by country region, with rapid initial escalation in Brazil's north and northeast. Prevalence is strongly associated with Indigenous ancestry and low socioeconomic status. These population subgroups are unlikely to be protected if the policy response to the pandemic by the national government continues to downplay scientific evidence.

FUNDING

Brazilian Ministry of Health, Instituto Serrapilheira, Brazilian Collective Health Association, and the JBS Fazer o Bem Faz Bem.

Prevalence of antibodies against SARS-CoV-2 according to socioeconomic and ethnic status in a nationwide Brazilian survey

OBJECTIVES

To investigate socioeconomic and ethnic group inequalities in prevalence of antibodies against SARS-CoV-2 in the 27 federative units of Brazil.

METHODS

In this cross-sectional study, three household surveys were carried out on May 14-21, June 4-7, and June 21-24, 2020 in 133 Brazilian urban areas. Multi-stage sampling was used to select 250 individuals in each city to undergo a rapid antibody test. Subjects answered a questionnaire on household assets, schooling and self-reported skin color/ethnicity using the standard Brazilian classification in five categories: white, black, brown, Asian or indigenous. Principal component analyses of assets was used to classify socioeconomic position into five wealth quintiles. Poisson regression was used for the analyses.

RESULTS

25 025 subjects were tested in the first, 31 165 in the second, and 33 207 in the third wave of the survey, with prevalence of positive results equal to 1.4%, 2.4%, and 2.9% respectively. Individuals in the poorest quintile were 2.16 times (95% confidence interval 1.86; 2.51) more likely to test positive than those in the wealthiest quintile, and those with 12 or more years of schooling had lower prevalence than subjects with less education. Indigenous individuals had 4.71 (3.65; 6.08) times higher prevalence than whites, as did those with black or brown skin color. Adjustment for region of the country reduced the prevalence ratios according to wealth, education and ethnicity, but results remained statistically significant.

CONCLUSIONS

The prevalence of antibodies against SARS-CoV-2 in Brazil shows steep class and ethnic gradients, with lowest risks among white, educated and wealthy individuals.

Early child stimulation and attention-related executive functions at 11 years: 2004 Pelotas birth cohort study

The study aimed to explore associations between socioeconomic position (SEP) indicators, early child stimulation (ECS) and attention-related executive functions (EF) at age 11. Children born in Pelotas, Brazil, in 2004, were recruited to a birth cohort (n = 4231, non-response rate at recruitment < 1%) and followed from birth to age 11. SEP variables were family income and maternal schooling. At the 24 and 48-month follow-ups, five markers of cognitive stimulation and social interaction were recorded and positive answers were summed to a score ranging from 0 to 5. At age 11, attentional-switching and control, and selective-attention were assessed using the adapted Test-of-Everyday-Attention-for-Children (TEA-Ch). We used multivariable logistic regression models and mediation analysis to investigate potential mediator role of ECS in the association between SEP and EF. 3106 children were included in the analyses. Less than 7% of the more stimulated individuals showed low performance in attention-related EFs at age 11 compared with almost 20% in the bottom groups of stimulation. Higher child stimulation scores were associated with fewer impairments in attentional-control (OR adj 0.84; CI 95% 0.72-0.98) and attentional-switching (OR adj 0.85; CI 95% 0.73-0.99). Mediation analysis suggested that for attentional-switching, ECS mediated almost 20% of the total protective effect of maternal schooling for impaired EF. Assuming causal relationships, if maximum stimulation was provided to all children, the advantageous effect of maternal schooling on EF would be reduced by 47%. ECS may represent a protective factor for cognitive impairments in childhood and can be easily implemented at relatively low cost.

Population-based surveys of antibodies against SARS-CoV-2 in Southern Brazil

Population-based data on COVID-19 are urgently needed. We report on three rounds of probability sample household surveys in the state of Rio Grande do Sul (Brazil), carried out in nine large municipalities using the Wondfo lateral flow point-of-care test for immunoglobulin M and G antibodies against SARS-CoV-2 (https://en.wondfo.com.cn/product/wondfo-sars-cov-2-antibody-test-lateral-flow-method-2/). Before survey use, the assay underwent four validation studies with pooled estimates of sensitivity (84.8%; 95% confidence interval (CI) = 81.4-87.8%) and specificity (99.0%; 95% CI = 97.8-99.7%). We calculated that the seroprevalence was 0.048% (2/4,151; 95% CI = 0.006-0.174) on 11-13 April (round 1), 0.135% (6/4,460; 95% CI = 0.049-0.293%) on 25-27 April (round 2) and 0.222% (10/4,500; 95% CI = 0.107-0.408) on 9-11 May (round 3), with a significant upward trend over the course of the surveys. Of 37 family members of positive individuals, 17 (35%) were also positive. The epidemic is at an early stage in the state, and there is high compliance with social distancing, unlike in other parts of Brazil. Periodic survey rounds will continue to monitor trends until at least the end of September, and our population-based data will inform decisions on preventive policies and health system preparedness at the state level.

Population-based surveys of antibodies against SARS-CoV-2 in Southern Brazil

Population-based data on COVID-19 are urgently needed. We report on three rounds of probability sample household surveys in the state of Rio Grande do Sul (Brazil), carried out in nine large municipalities using the Wondfo lateral flow point-of-care test for immunoglobulin M and G antibodies against SARS-CoV-2 (https://en.wondfo.com.cn/product/wondfo-sars-cov-2-antibody-test-lateral-flow-method-2/). Before survey use, the assay underwent four validation studies with pooled estimates of sensitivity (84.8%; 95% confidence interval (CI) = 81.4-87.8%) and specificity (99.0%; 95% CI = 97.8-99.7%). We calculated that the seroprevalence was 0.048% (2/4,151; 95% CI = 0.006-0.174) on 11-13 April (round 1), 0.135% (6/4,460; 95% CI = 0.049-0.293%) on 25-27 April (round 2) and 0.222% (10/4,500; 95% CI = 0.107-0.408) on 9-11 May (round 3), with a significant upward trend over the course of the surveys. Of 37 family members of positive individuals, 17 (35%) were also positive. The epidemic is at an early stage in the state, and there is high compliance with social distancing, unlike in other parts of Brazil. Periodic survey rounds will continue to monitor trends until at least the end of September, and our population-based data will inform decisions on preventive policies and health system preparedness at the state level.

[Expenditures on childbirth care: a comparison of the 2004 and 2015 birth cohorts in Pelotas, Rio Grande do Sul State, Brazil]

Although most childbirth care in Brazil is financed by the Brazilian Unified National Health System (SUS), there are out-of-pocket expenditures (private personal costs) involved in births. This study aims to compare maternal out-of-pocket expenditures in births of children from the Pelotas Birth Cohorts of 2004 and 2015. The study drew on information collected right after birth and at three months of age. The target variables include sociodemographic and economic data, private health plan coverage, and expenditures related to the birth. Values from 2004 were adjusted to 2015 by the general price index. There was an increase in private health plan coverage from 33.4% (95%CI: 31.9-34.9) to 45.1% (95%IC: 43.6-46.7) in the target period, directly associated with the families' socioeconomic status (p < 0.001). There was an increase in mean expenditures on hospitalization for the birth, from BRL 60.38 (SD = 288.66) to BRL 171.15 (SD = 957.07), and in additional medical expenditures, from BRL 191.60 (SD = 612.86) to BRL 1,424.80 (SD = 4,459.16) among mothers admitted to hospital under their private health plans (and there was no significant difference in these expenditures for mothers that opted for direct payment). There was an important increase in expenditures for childbirth care, especially among mothers admitted to hospital under private health plans.

Socio-demographic and economic inequalities in modern contraception in 11 low- and middle-income countries: an analysis of the PMA2020 surveys

Background

Contraception is a key component of sustainable development, empowering women, reducing the risk of maternal and child mortality and promoting economic growth. It is part of the Sustainable Development Goals agenda, where the aim is to achieve universal access to sexual and reproductive health. Our objective was to evaluate trends and inequalities in modern contraceptive prevalence, and according to the type of modern contraceptive, in 11 low- and middle-income countries that are partners of the Family Planning 2020 initiative.

Methods

Analyses were performed using 62 Performance Monitoring and Accountability 2020 (PMA2020) surveys from 11 countries. Forty surveys were nationally representative, while 22 had regional coverage. Regional surveys were analyzed separately, totalizing 15 geographies from 11 countries. We described trends on modern contraceptive prevalence, and its subtypes (short- and long-acting reversible contraceptives, and permanent methods), by calculating absolute average annual changes. Absolute inequalities on the prevalence of modern contraceptives were assessed for the most recent survey of each geography using the slope index of inequality, and according to wealth, education and age.

Results

The overall prevalence of modern contraception increased in most geographies analyzed, reaching a 7.2 percentage points increase per year in Lagos, Nigeria. This increase was mostly influenced by the long-acting reversible contraceptives, which increased in 73% of the geographies. Although the largest share of modern contraception is represented by short-acting reversible contraceptives, these are reducing and giving space for the long-acting methods. The exception was Rajasthan, India, where the permanent methods accounted for 70% of the modern contraception share, and their prevalence was almost 40%. Inequalities were identified in favor of richer, older and better educated women.

Conclusions

Out of the 15 geographies analyzed, 11 demonstrated an increase in overall modern contraceptive use – mainly driven by the uptake of long-acting reversible contraception. However, even in the groups with the highest prevalence, modern contraceptive use was at most 60% in most geographies. So, we are far from reaching the desired universal coverage proposed by the Sustainable Development Goals.

Low neurodevelopmental performance and behavioural/emotional problems at 24 and 48 months in Brazilian children exposed to acetaminophen during foetal development

BACKGROUND

Several studies have reported that there is an association between developmental and emotional/behavioural problems in children exposed to acetaminophen during foetal development. However, few studies have focused on development and behavioural outcomes in early life.

OBJECTIVES

To test the association between prenatal exposure to acetaminophen and low neurodevelopmental performance at 24 months and behavioural/emotional problems at 48 months of life.

METHODS

We used data from the 2004 Pelotas Birth Cohort, a population-based longitudinal prospective study. Neurodevelopment was evaluated at 24 months using Battelle's Developmental Inventory (BDI) (n = 3737). We assessed global function as well as each domain (personal-social, adaptative, motor, cognitive, and communication). Behavioural/emotional problems were assessed at 48 months using the Child Behaviour Checklist (CBCL) (n = 3624). We used the CBCL total, externalising, and internalising symptomatology and individual subscales (withdrawn, somatic complaints, anxious/depressed, social problems, cognitive problems, attention problems, aggressive behaviour, and rule-breaking behaviour). Acetaminophen use during pregnancy was retrospectively assessed at the perinatal follow-up. Poisson regression and multiple linear regression analyses were used to test the association, adjusting for several family and maternal sociodemographic and health factors, medication use during pregnancy, and the sex of the child.

RESULTS

Acetaminophen exposure during prenatal development was not associated with low neurodevelopmental performance at 24 months assessed using the BDI or to emotional and behavioural problems assessed at 48 months using the CBCL in the adjusted models.

CONCLUSIONS

We cannot confirm the existence of an association between acetaminophen used during pregnancy and low neurodevelopmental performance at 24 months and emotional/behavioural problems at 48 months of life based on the present results.

Trends in the prevalence of COVID-19 infection in Rio Grande do Sul, Brazil: repeated serological surveys

COVID-19, the disease produced by the virus SARS-CoV-2, has spread quickly throughout the world, leading the World Health Organization to first classify it as an international health emergency and, subsequently, declaring it pandemic. The number of confirmed cases, as April 11, surpassed 1,700,000, but this figure does not reflect the prevalence of COVID-19 in the population as, in many countries, tests are almost exclusively performed in people with symptoms, particularly severe cases. To properly assess the magnitude of the problem and to contribute to the design of evidence-based policies for fighting COVID-19, one must accurately estimate the population prevalence of infection. Our study is aimed at estimating the prevalence of infected individuals in the state of Rio Grande do Sul, Brazil, to document how fast the infection spreads, and to estimate the proportion of infected persons who present or presented symptoms, as well as the proportion of asymptomatic infections. Four repeated serological surveys will be conducted in probability samples of nine sentinel cities every two weeks. Tests will be performed in 4,500 participants in each survey, totaling18,000 interviews. Interviews and tests will be conducted at the participants' household. A rapid test for the detection of antibodies will be used; the test was validated prior to the beginning of the fieldwork.

Infant Formula Consumption Is Positively Correlated with Wealth, Within and Between Countries: A Multi-Country Study

BACKGROUND

In contrast with the ample literature on within- and between-country inequalities in breastfeeding practices, there are no multi-country analyses of socioeconomic disparities in breastmilk substitute (BMS) consumption in low- and middle-income countries (LMICs).

OBJECTIVE

This study aimed to investigate between- and within-country socioeconomic inequalities in breastfeeding and BMS consumption in LMICs.

METHODS

We examined data from the Demographic Health Surveys and Multiple Indicator Cluster Surveys conducted in 90 LMICs since 2010 to calculate Pearson correlation coefficients between infant feeding indicators and per capita gross domestic product (GDP). Within-country inequalities in exclusive breastfeeding, intake of formula or other types of nonhuman milk (cow/goat) were studied for infants aged 0-5 mo, and for continued breastfeeding at ages 12-15 mo through graphical presentation of coverage wealth quintiles.

RESULTS

Between-country analyses showed that log GDP was inversely correlated with exclusive (r = -0.37, P < 0.001) and continued breastfeeding (r = -0.74, P < 0.0001), and was positively correlated with formula intake (r = 0.70, P < 0.0001). Continued breastfeeding was inversely correlated with formula (r = -0.79, P < 0.0001), and was less strongly correlated with the intake of other types of nonhuman milk (r = -0.40, P < 0.001). Within-country analyses showed that 69 out of 89 did not have significant disparities in exclusive breastfeeding. Continued breastfeeding was significantly higher in children belonging to the poorest 20% of households compared with the wealthiest 20% in 40 countries (by ∼30 percentage points on average), whereas formula feeding was more common in the wealthiest group in 59 countries.

CONCLUSIONS

BMS intake is positively associated with GDP and negatively associated with continued breastfeeding in LMICs. In most countries, BMS intake is positively associated with family wealth, and will likely become more widespread as countries develop. Urgent action is needed to protect, promote, and support breastfeeding in all income groups and to reduce the intake of BMS, in light of the hazards associated with their use.

Association of risk behaviours, socio-economic characteristics and academic progress in adolescents: an analysis of the 1993 birth cohort in Pelotas, Brazil

To analyze how socio-economic factors and behavioural characteristics are related to the failure of academic progress. Data of the 1993 Birth Cohort of the city of Pelotas, Brazil, were analyzed using four follow-up waves. As a measure of the failure of academic progress, we used indicators of the age-grade gap. We analyzed the association of demographic, socio-economic, and behavioural characteristics. Factors associated with failure of academic progress were assessed through logistic regression. There are a higher odds of the age-grade gap when the adolescent is not white, man, of low socio-economic status, whose parents have low schooling and living in large families. In relation to risk behaviours, alcohol and tobacco consumption represent higher odds of the age-grade gap at age 18. The results show that socio-economic factors and behavioural characteristics are important predictors of academic progress. Public policies that seek to promote education should be targeted at the most vulnerable groups, decreasing the observed inequalities.

Trends and inequalities in maternal and child health in a Brazilian city: methodology and sociodemographic description of four population-based birth cohort studies, 1982-2015

Background

Few low-middle-income countries have data from comparable birth cohort studies spanning over time. We report on the methods used by the Pelotas cohorts (1982, 1993, 2004 and 2015) and describe time trends in sociodemographic characteristics of the participant families.

Methods

During the four study years, all maternity hospitals in the city were visited daily, and all urban women giving birth were enrolled. Data on socioeconomic and demographic characteristics were collected using standardized questionnaires, including data on maternal and paternal skin colour, age and schooling, maternal marital status, family income and household characteristics. The analyses included comparisons of time trends and of socioeconomic and ethnic group inequalities.

Results

Despite a near 50% increase in the city’s population between 1982 and 2015, the total number of births declined from 6011 to 4387. The proportion of mothers aged ≥35 years increased from 9.9% to 14.8%, and average maternal schooling from 6.5 [standard deviation (SD) 4.2] to 10.1 (SD 4.0) years. Treated water was available in 95.3% of households in 1982 and 99.3% in 2015. Three-quarters of the families had a refrigerator in 1982, compared with 98.3% in 2015. Absolute income-related inequalities in maternal schooling, household crowding, household appliances and access to treated water were markedly reduced between 1982 and 2015. Maternal skin colour was associated with inequalities in age at childbearing and schooling, as well as with household characteristics.

Conclusions

During the 33-year period, there were positive changes in social and environmental determinants of health, including income, education, fertility and characteristics of the home environment. Socioeconomic inequality was also reduced.

Unsafe storage of household medicines: results from a cross-sectional study of four-year-olds from the 2004 Pelotas birth cohort (Brazil)

BACKGROUND

Unintentional child poisoning represents a significant public health problem across the globe, placing a substantial burden on health services emergency departments. Around the world, every year, thousands of children die as a result of physical injuries, most of which involve children under 5 years old. Medicines are the main products involved in poisoning, and children under 5 years old are the most vulnerable age group. The objective of this study was to measure the prevalence of unsafe storage of medicines in households with a 4-year-old child.

METHODS

We used data from the follow-up of 4-year-old in the 2004 Pelotas Birth Cohort Study in Brazil (N = 3799). "Unsafe storage" was considered present when medicines were stored unlocked and within reach of children (at a height below the eye level of the average adult). Independent variables included maternal and family socioeconomic and demographic characteristics and the child's health care. All information was collected during household interviews with the mothers using a standardized questionnaire. The overall prevalence rate with a 95% confidence interval (95% CI) and the prevalence associated with various independent variables were determined.

RESULTS

The storage of medicines in unlocked areas was reported by 80.9% of the mothers, and, within reach of children for 26.5%. The overall prevalence rate of unsafe storage of medicines was 21.4% (20.1-22.7%). The main storage locations used were the kitchen (57.0%) and bedroom (53.3%).

CONCLUSIONS

The results indicate that medicines were unsafely stored in a 21.4% number of homes, which can contribute to the vulnerability of children to poisoning from medicines. To minimize this risk, education about the safe storage of medicines should be reinforced by health professionals.

How different online recruitment methods impact on recruitment rates for the web-based coortesnaweb project: a randomised trial

Background

The number of web-based E-epidemiologic studies using online recruitment methods is increasing. However, the optimal online recruitment method in terms of maximizing recruitment rates is still unknown. Our aim was to compare the recruitment rates of three online recruitment methods and to describe how these rates differ according to individual’s socioeconomic and demographic factors.

Methods

A total of 2394 members of the 1993 Pelotas birth cohort that provided an e-mail address, a Facebook name, and a WhatsApp number during a face-to-face follow-up were randomly allocated to be recruited by e-mail, Facebook or WhatsApp (798 individuals per method). This was a parallel randomised trial applying a block randomisation (block size = 3). Between January and February 2018, we sent messages inviting them to register into the web-based coortesnaweb platform. Recruitment rates were calculated for each method, and stratified according to the individual’s socioeconomic and demographic characteristics. We also analysed absolute and relative inequalities on recruitment according to schooling and socioeconomic position.

Results

Out of the 2394 individuals analysed, 642 registered into the platform. The overall recruitment rate was 26.8%. Recruitment rates for women were almost 10 percentage points higher compared to men. Facebook was the most effective recruitment method, as 30.6% of those invited through the social network were recruited. Recruitment rates of e-mail and WhatsApp were similar (recruitment rate = 24.9%). E-mail and Facebook were the most effective recruitment methods to invite highly educated and wealthier individuals. However, sending e-mails to recruit individuals also reflected in the highest inequalities according to schooling and socioeconomic position. In contrast, the lowest inequalities according to socioeconomic position were observed using Facebook.

Conclusions

Facebook was the most effective online recruitment method, also achieving the most equitable sample in terms of schooling and socioeconomic position. The effectiveness of online recruitment methods depends on the characteristics of the sample. It is important to know the profile of the target sample in order to decide which online recruitment method to use.

Trial registration

Brazilian Registry of Clinical Trials, identifier: RBR-3dv7gc, retrospectively registered in 10 April 2018.

Electronic supplementary material

The online version of this article (10.1186/s12874-019-0767-z) contains supplementary material, which is available to authorized users.

Gender norms and health: insights from global survey data

Despite global commitments to achieving gender equality and improving health and wellbeing for all, quantitative data and methods to precisely estimate the effect of gender norms on health inequities are underdeveloped. Nonetheless, existing global, national, and subnational data provide some key opportunities for testing associations between gender norms and health. Using innovative approaches to analysing proxies for gender norms, we generated evidence that gender norms impact the health of women and men across life stages, health sectors, and world regions. Six case studies showed that: (1) gender norms are complex and can intersect with other social factors to impact health over the life course; (2) early gender-normative influences by parents and peers can have multiple and differing health consequences for girls and boys; (3) non-conformity with, and transgression of, gender norms can be harmful to health, particularly when they trigger negative sanctions; and (4) the impact of gender norms on health can be context-specific, demanding care when designing effective gender-transformative health policies and programmes. Limitations of survey-based data are described that resulted in missed opportunities for investigating certain populations and domains. Recommendations for optimising and advancing research on the health impacts of gender norms are made.

Utilization of the Brazilian public health system by privately insured individuals: a literature review

More than one in four Brazilians have private health insurance (PHI), even thought it covers mostly the same procedures as the Brazilian Unified National Health System (SUS). This literature review included articles and monographs published since 1990 about the utilization of SUS by privately insured individuals. Considering outpatient care and hospitalization, privately insured people in Brazil use SUS in approximately 13% of the times they receive health care, and approximately 7% of people receiving care paid by SUS are privately insured; these findings vary depending on the type of service studied and on study methods. Utilization of SUS is more frequent in less developed regions, by people with more restricted PHI plans and by people with worse health status. Privately insured people report the limitations of PHI plans as their reasons for resorting to SUS. Sometimes, beneficiaries of PHI plans owned by nonprofit hospitals (which also provide health care financed by SUS) have easier access to care than uninsured people financed by SUS. Anecdotally, privately insured people are satisfied with SUS, but not to the point of adopting SUS as their preferred source of care. In short, for privately insured people, SUS only plays a secondary role in their health care. Despite PHI taking over part of the SUS's health care demand, PHI represents a restriction of the universal, equitable character of the SUS.

Infant nutrition and growth: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Levels of child undernutrition have declined in many middle-income countries, whereas overweight and obesity have increased. We describe time trends in nutritional indicators at age 1 year in the 1982, 1993, 2004 and 2015 Pelotas (Brazil) Birth Cohorts.

METHODS

Each study included all children born in the urban area of the city, with over 4 200 births in each cohort. Children were measured at approximately 12 months of age. Anthropometric indicators were calculated according to World Health Organization Growth Standards. Stunting and wasting were defined as <-2 Z scores for length for age and weight for length, and overweight as >2 Z scores for weight for length. Prevalence was stratified by sex, maternal skin colour and family income.

RESULTS

The prevalence of stunting declined by 53% (from 8.3% to 3.9%) from 1982 to 2015. Wasting prevalence remained stable at low levels (1.8% in 1982 and 1.7% in 2015), whereas overweight increased by 88% (6.5% to 12.2%). Undernutrition was more common among boys, those born to mothers with brown or black skin colour and in the poorest quintile of families. Socioeconomic inequalities in undernutrition decreased markedly over time. Overweight was markedly more common among the rich in 1982, but fast increase among the poor eliminated socioeconomic differences by 2015, when all groups showed similar prevalence.

CONCLUSIONS

Our results confirm the rapid nutrition transition in Brazil, with marked reduction in levels and inequalities in undernutrition in parallel with a rapid increase in overweight, which became the main nutritional problem for children.

Changes in overall and regional body fatness from childhood to early adolescence

Children weight gain is mostly due to fat-free mass than fat mass, but the changes in body composition dynamics related to child growth can be attributed to the obesity epidemic. We aimed to assess changes in measures of body composition from 6 to 11 years of age according to sex, and to examine whether changes in these measures are associated with sociodemographic characteristics. A longitudinal study using data from the 2004 Pelotas Birth Cohort was conducted, and assessed body composition and fat distribution through measures of BMI, fat mass index, fat-free mass index, and android and gynoid fat mass percentages from DXA. Changes in body fatness were calculated as the difference between measures collected at 6 and 11 years of age, and linear regression models were used to assess changes in body composition according to sociodemographic characteristics. An increase in mean BMI z-score from 6 to 11 years was observed only in boys and obesity prevalence reached one out of four boys and one out of five girls. There was an increase in fat mass percentage, fat mass index and android fat mass, with this effect more accentuated in boys when compared to girls. Maternal BMI was the most consistent factor associated with change in body fatness. Children from mothers with obesity showed larger increases in fat mass percentage, fat mass index and android fat mass. There was an increase in body fatness and a centralisation of body shape, mostly associated with male sex and maternal obesity. These results may indicate an early risk of non-communicable diseases in children from the Pelotas 2004 Birth Cohort.

Income-related inequality and inequity in children's health care: A longitudinal analysis using data from Brazil

The Brazilian Unified Health System was created in the late 1980s to ensure free universal access to health care and was funded by taxes and social contributions. The persistent inequity in access to health services in favour of richer individuals in Brazil has been observed in the literature. However, to the best of our knowledge, no measurement of inequality in medicine use or private health insurance (PHI) among children has been performed with longitudinal data. This paper uses inequality indices and their decompositions to analyse the income-related inequalities/inequities in children's health care in the city of Pelotas, Brazil, using longitudinal data following children from 12 to 72 months of age. Our sample with data in all waves has between 1877 and 2638 children (varying according to outcome). We seek to answer three questions: i) How does the inequality/inequity in health care evolve as children grow up? ii) What are the main factors associated with inequality in children's health care? iii) How much of the change in inequality/inequity is explained by mobility in children's health care and income mobility? We found that inequities in health care have their beginnings in early childhood but that there was a reduction in inequity at 72 months of age. Ownership of children's PHI was associated with greater pro-rich inequity in health care. The reduction in inequality/inequity was linked to mobility in the sense that initially poorer children had greater gains in health care (a greater increase in PHI ownership and a lower reduction in medicine use). Despite this improvement among the poorest, apparently, the Brazilian public health service seems to fail to ensure equity in health care use among children, with possible long-term consequences on inequalities in health.

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The inequities in health care have their beginnings even in early childhood.

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Income and mother's education have a strong contribution in the inequalities.

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Private health insurance has strong contribution in inequalities of medicine use.

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There was reduction in inequity for children's health care in Pelotas/Brazil.

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This improvement for poorest children occurred when they reached 72 months.

Socioeconomic inequalities in access to skilled birth attendance among urban and rural women in low-income and middle-income countries

Introduction

Rapid urbanisation is one of the greatest challenges for Sustainable Development Goals. We compared socioeconomic inequalities in urban and rural women’s access to skilled birth attendance (SBA) and to assess whether the poorest urban women have an advantage over the poorest rural women.

Methods

The latest available surveys (DemographicHealth Survey, Multiple Indicators Cluster Surveys) of 88 countries since 2010 were analysed. SBA coverage was calculated for 10 subgroups of women according to wealth quintile and urban-rural residence. Poisson regression was used to test interactions between wealth quintile index and urban-rural residence on coverage. The slope index of inequality (SII) and concentration index were calculated for urban and rural women.

Results

37 countries had surveys with at least 25 women in each of the 10 cells. Average rural average coverage was 72.8 % (ranging from 17.2% % in South Sudan to 99.9 % in Jordan) and average urban coverage was 80.0% (from 23.6% in South Sudan to 99.7% in Guyana. In 33 countries, rural coverage was lower than urban coverage; the difference was significant (p<0.05) in 15 countries. The widest urban/rural coverage gap was in the Central African Republic (32.8% points; p<0.001). Most countries showed narrower socioeconomic inequalities in urban than in rural areas. The largest difference was observed in Panama, where the rural SII was 77.1% points larger than the urban SII (p<0.001). In 31 countries, the poorest rural women had lower coverage than the poorest urban women; in 20 countries, these differences were statistically significant (p<0.05).

Conclusion

In most countries studied, urban areas present a double advantage of higher SBA coverage and narrower wealth-related inequalities when compared with rural areas. Studies of the intersectionality of wealth and residence can support policy decisions about which subgroups require special efforts to reach universal coverage.

Is intrauterine exposure to acetaminophen associated with emotional and hyperactivity problems during childhood? Findings from the 2004 Pelotas birth cohort

BACKGROUND

Longitudinal studies have consistently reported that prenatal exposure to acetaminophen can to lead to an increased risk of attention deficit-hyperactivity disorder during childhood. This study aimed to investigate the association between intrauterine exposure to acetaminophen and the presence of emotional and behavioral problems at the ages of 6 and 11 years in a low-middle income country.

METHODS

We performed a prospective longitudinal population-based study using data from the 2004 Pelotas birth cohort. From the 4231 initial cohort participants, 3722 and 3566 children were assessed at 6 and 11 years of age, respectively. The outcomes were assessed using the parent version of Strengths and Difficulties Questionnaire (SDQ). The cut-off points established for the Brazilian population were used to categorize the outcomes. Crude and adjusted odds ratio were obtained through logistic regression.

RESULTS

Acetaminophen was used by 27.5% (95% confidence interval [CI]: 26.1-28.9) of the mothers at least once during pregnancy. The prevalence of emotional problems at 6 and 11 years was 13.6 and 19.9%, respectively. For hyperactivity problems, prevalence was 13.9 and 16.1%, respectively. Intrauterine exposure to acetaminophen increased the odds of having emotional (odds ratio [OR] = 1.47; 95% CI: 1.07-2.02) and hyperactivity/inattention (OR = 1.42; 95% CI: 1.06-1.92) problems in 6-year-old boys. At the age of 11, a small decrease in the effect was observed for both outcomes after adjustment: OR = 1.31 (95% CI: 0.99-1.73) for emotional problems and OR = 1.25 (95% CI: 0.95-1.65) for hyperactivity/inattention in boys. No association for any phenotypes at both ages was observed for girls.

CONCLUSION

The effect of intrauterine exposure to acetaminophen in emotional and hyperactivity symptoms was dependent on sex in a Brazilian cohort. While it seemed to be important for boys, mainly at 6 years of age, for girls, no association was observed.