Maternal smoking during pregnancy and intelligence quotient of offspring aged 18 and 30 years: Evidence from two birth cohorts in southern Brazil

Maternal smoking during pregnancy causes several harmful effects, including deficits in the intelligence quotient (IQ), a measure associated with academic achievements and higher socioeconomic position. We aimed to measure the association between maternal smoking during pregnancy and offspring's IQ in two birth cohorts from Pelotas, Brazil. Data from the 1982 and 1993 birth cohorts were analyzed. Smoking during pregnancy was ascertained at the perinatal follow-up, and IQ was measured at 30 years (1982) and 18 years (1993). Simple and multiple linear regressions were used for crude and adjusted analysis. Mediation analysis was performed using birth weight and breastfeeding as possible mediators. Data analysis was conducted in 2020. There were 3611 and 4050 participants from the 1982 and 1993 cohorts, respectively. After adjustment for potential confounders, the inverse association between smoking during pregnancy and children's IQ remained significant in both cohorts. Offspring of mothers who smoked during pregnancy had an average of 1.32 less IQ points (95%CI: -2.23, -0.242) in the 1982 cohort, and an average of 1.66 less IQ points (95%CI: -2.42, -0.90) in the 1993 cohort. Neither cohort showed association with paternal smoking (negative controls) after adjustment. Breastfeeding's mediated effects accounted for 26.2% and 23.9% of the association in the 1982 and 1993 cohorts, respectively, while birth weight's accounted for 6.8% and 30.1%, respectively; indirect effects were not significant. The inverse association between maternal smoking and IQ and the lack of association with paternal smoking reinforces our findings of a negative association between exposure and outcome.

Is Screen Time Throughout Adolescence Related to ADHD? Findings from 1993 Pelotas (Brazil) Birth Cohort Study

OBJECTIVE

This study investigated the association between screen time in adolescence and Attention Deficit Disorder (ADHD) at 22 years old.

METHOD

A sample of 2333 participants aged 11 years old without ADHD from the 1993 Pelotas Birth Cohort Study (Brazil) was followed up until the age of 22. Screen time variables included time spent in television, video game and computer at 11, 15, and 18 years old. ADHD was assessed at 22 years.

RESULTS

ADHD symptoms at 22 years was positively associated with television time at 11 years, computer time at 18 years and total screen time at ages 11, 15, and 18 years. Television time at 11 years and total screen time at 18 years were associated with diagnosis of ADHD at 22 years of age.

CONCLUSIONS

Our findings may contribute to future investigations of possible explanatory avenues for these associations.

Atraso na vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses de idade: Pesquisa Nacional de Saúde, 2013

Resumo: O objetivo foi estimar a prevalência do atraso nas três doses da vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses de idade, no Brasil, por meio dos dados da Pesquisa Nacional de Saúde (PNS) de 2013 e descrever o atraso em cada uma das doses segundo variáveis sociodemográficas, utilização de serviços e intervenções públicas de saúde. Foram utilizados dados da PNS, estudo transversal realizado em 2013. O desfecho foi o atraso pelo menos em uma das três doses da vacina tetravalente. Considerou-se como atraso a dose recebida pelo menos 30 dias após a data preconizada, segundo informação da caderneta de vacinação. A prevalência do atraso foi descrita segundo variáveis sociodemográficas e utilização de serviços de saúde. Realizou-se análise descritiva obtendo-se frequências absolutas e relativas e seus respectivos intervalos de 95% de confiança. Das 2.016 crianças com informações coletadas, 1.843 foram analisadas. A prevalência de atraso de pelo menos uma dose da vacina foi de 44%. Observou-se atraso de 14,8% na primeira, 28,8% na segunda e 45,4% na terceira dose, sendo que 10% das crianças tiveram atraso nas três doses. Maiores prevalências de atraso foram encontradas em crianças do sexo masculino, de cor da pele parda, pertencentes ao quintil mais pobre de riqueza, moradores da zona rural e da Região Norte do Brasil. Evidenciou-se alta prevalência de atraso na vacina tetravalente (DTP+Hib) em crianças de 12 a 23 meses do Brasil, sendo maior na terceira dose.

Innovative methods to analyse the impact of gender norms on adolescent health using global health survey data

Background

Understanding how gender norms affect health is an important entry point into designing programs and policies to change norms and improve gender equality and health. However, it is rare for global health datasets to include questions on gender norms, especially questions that go beyond measuring gender-related attitudes, thus limiting gender analysis.

Methods

We developed five case studies using health survey data from six countries to demonstrate approaches to defining and operationalising proxy measures and analytic approaches to investigating how gender norms can affect health. Key findings, strengths and limitations of our norms proxies and methodological choices are summarised.

Findings

Case studies revealed links between gender norms and multiple adolescent health outcomes. Proxys for norms were derived from data on attitudes, beliefs, and behaviours, as well as differences between attitudes and behaviours. Data were cross-sectional, longitudinal, census- and social network-based. Analytic methods were diverse. We found that gender norms affect: 1) Intimate partner violence in Nigeria; 2) Unhealthy weight control behaviours in Brazil and South Africa; 3) HIV status in Zambia; 4) Health and social mobility in the US; and 5) Childbirth in Honduras.

Interpretation

Researchers can use existing global health survey data to examine pathways through which gender norms affect health by generating proxies for gender norms. While direct measures of gender norms can greatly improve the understanding of how gender affects health, proxy measures for norms can be designed for the specific health-related outcome and normative context, for instance by either aggregating behaviours or attitudes or quantifying the difference (dissonance) between them. These norm proxies enable evaluations of the influence of gender norms on health and insights into possible reference groups and sanctions for non-compliers, thus informing programmes and policies to shape norms and improve health.

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This article presents effective methods to study gender norms in existing global health survey data.

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We devised conceptual pathways linking gender norms to gender-based health disparities.

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We identified gender norms proxies and reference groups enforcing the norm.

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We tested hypotheses linking gender norms to health.

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These methods can aid policy and programme design to advance gender equality and health.

Prevalence of symptoms of COVID-19 in the state of Rio Grande do Sul: results of a population-based study with 18,000 participants

OBJECTIVE

To evaluate the prevalence of reports of symptoms of COVID-19 among individuals with and without antibodies and identify those with greater capability to predict the presence of antibodies against SARS-CoV-2.

METHODS

The study uses data collected in phases 5 to 8 of Epicovid-19-RS. The presence of antibodies against SARS-CoV-2 was evaluated by a rapid test. The occurrence of cough, fever, palpitations, sore throat, difficulty breathing, changes in taste and smell, vomiting, diarrhea, body pain, shaking, and headache since March 2020 was also evaluated. Then, the capability to predict the evaluated symptoms concerning the presence of antibodies was calculated.

RESULTS

A total of 18,000 individuals were interviewed and 181 had antibodies against COVID-19 in phases 5 to 8. The proportion of asymptomatic individuals was 19.9% among participants with antibodies and 49.7% among those without antibodies. All symptoms were reported more frequently by individuals with antibodies. The division of the prevalence of symptoms among individuals with antibodies by the prevalence among individuals without antibodies showed the following prevalence ratios: for changes in smell or taste (9.1), fever (4.2), tremors (3.9), breathing difficulty (3.2) and cough (2.8 times). Anosmia and fever were the symptoms with a greater capability to predict the presence of antibodies.

CONCLUSION

The prevalence of symptoms was higher among individuals with antibodies against SARS-CoV-2. The proportion of asymptomatic individuals was low. Altered smell or taste and fever were the symptoms that most predict the presence of antibodies. These results can help to identify probable cases, contributing to the clinical diagnosis and screening of patients for testing and isolation guidance in positive cases, especially in scenarios of the scarcity of diagnostic COVID-19 tests.

Association between cesarean section and human capital in adulthood: 1982 and 1993 Pelotas birth cohorts, Rio Grande do Sul State, Brazil

This study aims to assess the association between mode of delivery and human capital among young adults enrolled in the 1982 and 1993 Pelotas birth cohorts, Rio Grande do Sul State, Brasil. In 1982 and 1993, the maternity hospitals of the municipality were daily visited, the births identified, and those live births, whose family lived in the urban area of Pelotas, were examined and their mothers interviewed. Information on mode of delivery, vaginal or cesarean, was provided by the mother in the perinatal study. Performance in intelligence tests achieved schooling and income were evaluated in the 30 years visit at the 1982 cohort. At the 1993 cohort, schooling and income were assessed at the 22 years visit, whereas IQ was evaluated at 18 years. Tobacco smoking in adulthood and type of school was used as negative outcomes to strength causal inference. Initially, cesarean section was positively associated with human capital at adulthood, with the exception of income in the 1993 cohort. After controlling for confounders, the magnitude of the associations was strongly reduced, and the regression coefficients were close to the null value. The negative outcome analysis showed that, after controlling for confounding variables, the mode of delivery was not associated with tobacco smoking and type of school. Suggesting that the variables included in the regression model to control for confounding, provided an adequate adjustment and it is unlikely that the results are due to residual confounding by socioeconomic status. On the other hand, considering the short- and long-term risks and the epidemic of cesarean sections, measures should be implemented to reduce its prevalence.

Associations between sleep duration trajectories from adolescence to early adulthood and working memory, schooling and income: a prospective birth cohort study from Brazil

OBJECTIVE

This study aimed to evaluate the relationship between sleep duration trajectories from adolescence to early adulthood and working memory, schooling and income at 22 years in the Pelotas 1993 Birth Cohort.

METHODS

Sleep duration was self-reported at ages 11, 18 and 22. Sleep trajectories were identified using finite mixture models. Schooling was recorded as the number of completed years of education. Working memory was evaluated using The Digit Span test and income was recorded for who reported have a job and received a payment for this in the previous month. All analyses were stratified by sex.

RESULTS

We used crude and adjusted (for demographic, health and behavior characteristics measured at perinatal and 11-years) linear or quantile regression analyses. A total of 2915 individuals were included. Three trajectories for males were used: "increase and maintenance" (3.4%), "fast reduction and maintenance" (45.0%) and "constant reduction" (51.6%). For females, we used the trajectories: "increase and decrease" (2.4%), "fast reduction and maintenance" (25.6%) and "constant reduction" (72.0%). Males from "increase and maintenance" and females from "increase and decrease" trajectories scored, on average, 1.6 and 1.8 points lower, respectively, in working memory test. They presented a median of 1.4 and 2.6 fewer schooling years, respectively, compared to individuals from the "fast reduction and maintenance" trajectory. Regarding income, no significant association was observed.

CONCLUSION

Sleep duration during adolescence could affect cognitive and educational outcomes in early adulthood. Individuals who presented the expected sleep trajectory (decrease of sleep duration across adolescence) presented better outcomes.

Influenza vaccination in older adults during the COVID-19 pandemic: a population-based study in 133 Brazilian cities

Routine immunization during pandemics can be harmed. This study estimated the influenza vaccination coverage in older adults during the COVID-19 through the EPICOVID-19, a population-based study conducted in 133 cities from the 26 Brazilian states and Federal District. We selected 25 census tracts per city, with probability proportional to the tract's size, ten households by census tract, and one random individual interviewed. A total of 8,265 older adults (≥60 years old) were interviewed and asked whether they had been vaccinated against flu in 2020. Vaccination coverage was 82.3% (95% CI: 80.1-84.2) with no difference by gender, age, and region; higher vaccination coverage was observed among the wealthiest (84.7% versus 80.1% in the poorest) and among the more educated (87.3% versus 83.2% less educated); lower coverage among indigenous (56.9% versus > 80% among other ethnic groups). A positive association was identified with the number of comorbidities among men but not among women. Most of the population was vaccinated (97.5%) in the public health system. The private network was chosen mainly in the South by the wealthiest and more educated. Vaccination coverage was seven percentage points lower than the government target (90%), and inequalities should be reversed in future campaigns.

[Validation study on self-reported visual impairment among undergraduate students at the Federal University of Pelotas]

The objectives of the study were to assess the prevalence of self-reported visual impairment among undergraduate students between 18 and 39 years of age at the Federal University of Pelotas, and to validate a question about visual impairment in a subsample of the participants. A cross-sectional study was conducted by asking the question "Do you have any difficulty seeing up close and/or in the distance?" As the gold standard for the validation study, visual acuity (VA) was measured using the Snellen chart. Patients with VA less than 20/40 in either eye were considered to have reduced VA. The prevalence of self-reported visual impairment was 37.3% (95% CI: 35.1-39.6) and VA less than 20/40 in either eye was 6.9% (95% CI: 5.3-8.9). The question revealed sensitivity of 71.4% (95 CI: 57.8-82.7), specificity of 66.9% (95% CI: 63.4-70.2), positive predictive value of 13.8% (95% CI: 10.0-18.3), and negative predictive value of 96.9% (95% CI: 95,1-98.2). The results indicated a high prevalence of self-reported visual impairment among university students. The question showed reasonable sensitivity and specificity and high negative predictive value and may be used for screening for ophthalmological evaluation among young adult university students.

Chronic non-communicable diseases and COVID-19: EPICOVID-19 Brazil results

OBJECTIVE

Describing the prevalence of chronic diseases and associated socioeconomic and demographic factors, evaluating the patterns of social distancing and the antibodies prevalence against SARS-CoV-2 and COVID-19 symptoms in carriers and non-carriers of chronic diseases.

METHODS

Data from 77,075 individuals aged 20 to 59 from three steps of the EPICOVID-19 Brazil (a nationwide serological survey conducted between May and June, 2021) were assessed. The presence of antibodies against SARS-CoV-2 was examined by rapid tests. Self-reported prevalence of hypertension, diabetes, asthma, cancer, chronic kidney disease and heart disease were investigated. The prevalence of mask use, adherence to isolation measures and antibodies were evaluated separately amid carriers and non-carriers of chronic diseases. The prevalence of symptoms was analyzed among carriers and non-carriers of chronic diseases with antibodies.

RESULTS

The prevalence of at least one chronic disease was 43%, higher in the Southeast region, among white and indigenous individuals, women, less schooled and in lower socioeconomic position. The use of masks when leaving home was similar among carriers and non-carriers of chronic diseases (98%). The proportion of participants who reported adherence to isolation measures was higher amid carriers (15.9%) than non-carriers (24.9%) of chronic diseases. The prevalence of antibodies to SARS-CoV-2 was similar amongst carriers and non-carriers (2.4% and 2.3%). The prevalence of cough, dyspnea, palpitations and myalgia was significantly higher among carriers, but the proportion of symptomatic patients was similar between groups.

CONCLUSION

The prevalence of chronic diseases in Brazil is high and the COVID-19 pandemic affects carriers and non-carriers of chronic diseases similarly. Carriers present more severe forms of COVID-19 and higher prevalence of symptoms. Greater adherence to social distancing measures among chronic patients is disassociated from a lower incidence of COVID-19 in this group.

Association of the length of time using computers and mobile devices with low back, neck and mid-back pains: findings from a birth cohort

OBJECTIVES

Neck and low back pains are the leading causes of years lived with disability, and using computers or mobile devices in excess could be risk factors for back pain. Our aim was to evaluate the association of the length of time using computers and mobile devices with neck, mid-back and low back pains and the number of regions with pain.

STUDY DESIGN

Cross-sectional study nested in the 1993 Pelotas birth cohort with young adults aged 22 years.

METHODS

Outcomes analyzed were neck, mid-back and low back pains and the number of regions with pain. Exposures were the number of daily hours using computers and mobile devices. Crude and adjusted analyses were performed to estimate prevalence ratios using Poisson regression.

RESULTS

Almost half of the sample reported having back pain, the low back pain being the most prevalent. Compared with individuals using mobile devices for less than one hour, the prevalence of neck pain was 1.41 and 1.81 times higher among individuals using mobile devices from three to seven hours and for seven or more hours per day, respectively. Neck pain prevalence was 1.47 times higher among individuals using computers for more than two hours than among those not using computers. Using mobile devices for seven hours or more was associated to 1.19 times higher prevalence of low back pain.

CONCLUSION

Using mobile devices in excess was associated to neck and low back pains, while the use of computers in excess was associated only to neck pain. It is important that guidelines are developed to recommend the adequate length of time that computers and mobile devices should be used to prevent back pain.

Maternal smoking during pregnancy and intelligence quotient in offspring: A systematic review and meta-analysis

BACKGROUND

Exposure to tobacco during pregnancy may disrupt fetal brain development and impact offspring cognitive development.

AIMS

To perform a systematic review and meta-analysis on maternal smoking during pregnancy and intelligence quotient (IQ) in childhood, adolescence, and adulthood.

METHODS

We searched PubMed, Lilacs, PsycINFO, and Web of Science. Original articles evaluating tobacco use/exposure during pregnancy and the offspring's IQ as the outcome. The review protocol is registered in PROSPERO (number CRD 42,019,116,257). For the meta-analysis, we included studies with information on the regression coefficient and its confidence interval (CI) or standard error. Random effects model was used for pooling the estimates.

RESULTS

25 studies were included in the review, and of these 14 met the inclusion criteria for the meta-analysis. The overall pooled estimate showed that subjects who were exposed to maternal smoking during pregnancy presented lower IQ scores, compared to those not exposed to maternal smoking (β -1.30; 95 % CI -1.74, -0.86; I² = 87.8 %); IQ scores were also lower in crude (β -5.46; 95 % CI -7.31, -3.60; I²: 79.0 %) and adjusted pooled estimates (β =-0.45; 95 % CI -0.76, -0.13; I² = 80.4 %), for the group exposed to maternal smoking. In the stratified analysis, an inverse association was also observed in studies with large sample size (n≥1000 participants) (β=-0.49; 95 % CI -0.96, -0.02), among those performed with adolescents (β=-1.16; 95 % CI -2.18, -0.14), and among those adjusted for maternal education (β=-0.57; 95 % CI -1.05, -0.08).

CONCLUSIONS

Our findings suggest that exposure to tobacco during pregnancy may have negative effects on IQ. However, the findings of this meta-analysis should be interpreted with caution.

Excess weight and obesity prevalence in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas and São Luís)

Our objective was to estimate the prevalence of excess weight and obesity, according to sex and income in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas, and São Luís). Participants in the Ribeirão Preto (1978/1979 and 1994), Pelotas (1982, 1993 and 2004) and São Luís (1997/1998) birth cohorts were included in different follow-ups from 7 years old onwards. Excess weight (overweight and obesity) were assessed by body mass index. The highest prevalences were observed in Ribeirão Preto (excess weight: 27.7% at 9-11 and 47.1% at 22-23 years; obesity: 8.6% at 9-11 and 19.8% at 22-23 years) while the smallest was in São Luís (excess weight: 5.4 to 7-9 and 17.2% at 18-19 years; obesity: 1.8% at 7-9 and 3.6% at 18-19 years). The younger the cohort, the greater the prevalence of excess weight and obesity when comparing similar age groups. Increases in obesity prevalence were greater than in excess weight prevalence. Women had lower excess weight prevalence in older cohorts and higher obesity prevalence in younger cohorts. Higher excess weight and obesity prevalence were observed in higher income children and adolescents, and in poorer adults. Differences in the prevalence of excess weight and obesity evidenced that individuals from younger cohorts are more exposed to this morbidity, as well as those who were born in the most developed city, low-income adults as well as children and adolescents belonging to families of the highest income tertile. Therefore, the results of this study indicate the need to prioritize actions aimed at younger individuals.

Prevalence of ideal cardiovascular health in young adults: A birth cohort from southern Brazil

BACKGROUND

Ideal cardiovascular health (ICH) aims at primordial prevention of cardiovascular diseases in the population. However, there is a lack of research describing ICH in youth from middle-income countries. The aims of this study were to describe the prevalence of ICH at 18- and 22-year-old and to investigate the influence of socioeconomic status.

METHODS

The sample consisted of participants from the Pelotas 1993 birth-cohort followed-up at 18- (n = 4,106) and 22-year-old (n = 3,810). Ideal metrics were created for diet, smoking, body mass index, physical activity, blood pressure, total cholesterol, and blood glucose. The presence of 4 or more ideal metrics was defined as ICH. Socioeconomic status was obtained using wealth quintiles calculated with factor analysis based on analysis based on the ownership of household and education. The impact of socioeconomic status on ICH metrics was statistically measured using the slope index of inequality.

RESULTS

The prevalence of ICH was 84.5% (95% confidence interval [CI] = 82.7-86.2%) and 84.1% (82.3-85.8%) at 18-year-old and decreased to 61.1% (58.4-63.7%) and 68.7% (66.2-71.2%) at 22-years old, for male and female, respectively. Socioeconomic status influenced ICH and its components differently in males and females. Wealthiest females had ICH prevalence 19 percentage points (pp) (11-27 pp) higher compared to the poorest, whereas poorest males had ICH prevalence 12 pp (1-21 pp) higher compared to the wealthiest. Longitudinal decreases in ICH components were mostly present in the poorest females.

CONCLUSIONS

In middle-income countries, the prevalence of ICH is high at 18-year-old and decreases in a 4-year follow-up. Socioeconomic status influences differently individuals' ICH between sexes. Efforts are needed to maintain ICH in youth and different strategies may be required between the social status.

RPS Brazilian Birth Cohorts Consortium (Ribeirão Preto, Pelotas and São Luís): history, objectives and methods

This paper describes the history, objectives and methods used by the nine Brazilian cohorts of the RPS Brazilian Birth Cohorts Consortium (Ribeirão Preto, Pelotas and São Luís) Common thematic axes are identified and the objectives, baseline periods, follow-up stages and representativity of the population studied are presented. The Consortium includes three birth cohorts from Ribeirão Preto, São Paulo State (1978/1979, 1994 and 2010), four from Pelotas, Rio Grande do Sul State (1982, 1993, 2004 and 2015), and two from São Luís, Maranhão State (1997 and 2010). The cohorts cover three regions of Brazil, from three distinct states, with marked socioeconomic, cultural and infrastructure differences. The cohorts were started at birth, except for the most recent one in each municipality, where mothers were recruited during pregnancy. The instruments for data collection have been refined in order to approach different exposures during the early phases of life and their long-term influence on the health-disease process. The investigators of the nine cohorts carried out perinatal studies and later studied human capital, mental health, nutrition and precursor signs of noncommunicable diseases. A total of 17,636 liveborns were recruited in Ribeirão Preto, 19,669 in Pelotas, and 7,659 in São Luís. In the studies starting during pregnancy, 1,400 pregnant women were interviewed in Ribeirão Preto, 3,199 in Pelotas, and 1,447 in São Luís. Different strategies were employed to reduce losses to follow-up. This research network allows the analysis of the incidence of diseases and the establishment of possible causal relations that might explain the health outcomes of these populations in order to contribute to the development of governmental actions and health policies more consistent with reality.

The neurodevelopmental nature of attention-deficit hyperactivity disorder in adults

BACKGROUND

Population studies have suggested that most adults with attention-deficit hyperactivity disorder (ADHD) did not have the disorder in childhood, challenging the neurodevelopmental conceptualisation of ADHD. Arbitrary definitions of age at onset and lack of defined trajectories were accounted for the findings.

AIMS

The objective of this study was to assess the proportion of individuals presenting with either a neurodevelopmental trajectory or late-onset disorder, and to assess risk factors associated with them.

METHOD

Data of 4676 individuals from the 1993 Pelotas birth cohort at 11, 15, 18 and 22 years of age were used. Polythetic and latent class mixed model analyses were performed to define ADHD trajectories from childhood to adulthood, and characterise the neurodevelopmental or late-onset courses. Regression models were applied to assess factors associated with different trajectories.

RESULTS

Classical polythetic analyses showed that 67% of those with ADHD at 22 years of age had a neurodevelopmental course of the disorder. Latent class mixed model analysis indicated that 78% of adults with ADHD had a trajectory of persistent symptoms, more common in males. The remaining adults with ADHD had an ascending symptom trajectory that occurred after puberty, with late-onset ADHD associated with female gender and higher IQ.

CONCLUSIONS

Both polythetic and latent trajectories analyses provided empirical evidence supporting that the large majority of adults with ADHD had a neurodevelopmental disorder.

Longitudinal Association Between Diet Quality and Asthma Symptoms in Early Adult Life in a Brazilian Birth Cohort

Background

The role of diet in the etiology of asthma is still inconclusive. This paper evaluated the longitudinal association between diet quality and chest wheezing in young adults.

Methods

This is a longitudinal study with follow-up information from 18- and 22-year-olds (18y and 22y) of the 1993 Pelotas (Brazil) Birth Cohort. Chest wheezing occurrence and number of events in the last year were reported at 22y. Diet quality was measured with a revised version of the Healthy Eating Index (IQD-R) for the Brazilian population at 18y and 22y by food frequency questionnaire referring to the last 12 months. The diet quality continuity was classified as good (always 1st IQD-R tertile), intermediate (always 2nd tertile/change tertile) and poor (always 3rd tertile).

Results

A total of 2986 young individuals were evaluated; 51.4% were female. Prevalence of wheezing at 22y was 10.1% (95% CI: 9.1–11.2), and of these patients, 10% reported at least one event in the past year. Better IQD-R score, both at 18y and at 22y, the lower the odds of wheezing in the past year. Regarding the diet quality continuity from 18y to 22y, staying on a poor diet increased by more than three-fold the odds of chest wheezing (OR=3.28; 95% CI: 1.84–5.84) and of wheezing events (OR=3.32; 95% CI: 1.89–5.85) compared to staying on a good diet, after adjustment for confounding variables.

Conclusion

The overall quality of the diet seems to be more important than the individual components in the effect on asthma symptoms. Low-quality diet persistence increased the odds of chest wheezing and the number of events.

EPICOVID19 protocol: repeated serological surveys on SARS-CoV-2 antibodies in Brazil

The first case of COVID-19 was reported in China in December 2019, and, as the virus has spread worldwide, the World Health Organization declared it a pandemic. Estimates on the number of COVID-19 cases do not reflect it real magnitude as testing is limited. Population based data on the proportion of the population with antibodies is relevant for planning public health policies. We aim to assess the prevalence of SARS-CoV-2 antibodies, presence of signs and symptoms of COVID-19, and adherence to isolation measures. A random sample comprising 133 sentinel cities from all states of the country will be selected. Three serological surveys, three weeks apart, will be conducted. The most populous municipality in each intermediate region of the country, defined by the Brazilian Institute of Geography and Statistics, was chosen as sentinel city. In each city, 25 census tracts will be selected, and 10 households will be systematically sampled in each tract, totaling 33,250 participants. In each household, one inhabitant will be randomly selected to be interviewed and tested for antibodies against SARS-CoV-2, using WONDFO SARS-CoV-2 Antibody Test. By evaluating a representative sample of Brazilian sentinel sites, this study will provide essential information for the design of health policies.

Sleep duration trajectories from adolescence to emerging adulthood: Findings from a population-based birth cohort

This study aimed to describe longitudinal trajectories of sleep duration, among adolescents and adults from the Pelotas (Brazil) 1993 Birth Cohort, as well as characterize different trajectories groups according to socioeconomic, demographic and behavior characteristics. Sleep duration, hours per day (from Monday to Friday), bedtime and wake-up time were self-reported by participants at ages 11, 18 and 22 years. Covariables included socioeconomic, demographic, health and behavior characteristics. Trajectory analysis was performed using a semi-parametric, group-based modelling approach. Prevalence and 95% confidence interval were obtained to describe covariables and sleep trajectory groups. Chi-square test was employed in statistical analysis and all analyses were stratified by sex. A total of 3.395 individuals were included in the analysis. In both sexes, bedtime became later across years, while wake-up time presented little variation. Differences according sex were more pronounced from 18 years onwards. Three trajectories of sleep duration from 11 to 22 years were identified for males: "increase and maintenance" (3.4%), "fast reduction and maintenance" (45.0%) and "constant reduction" (51.6%). While in females the trajectories identified were: "increase and decrease" (2.4%), "fast reduction and maintenance" (25.6%) and "constant reduction" (72.0%). Men and women who belong to trajectories with longer sleep durations were more likely to present higher percentages of some risk behaviors and poor socioeconomic condition. Our results have provided longitudinal information regarding sleep duration trajectories in a medium-sized city in Brazil, aiming at filling an existing gap in literature from low- and middle-income countries.

Differential influences of early growth and social factors on young children's cognitive performance in four low-and-middle-income birth cohorts (Brazil, Guatemala, Philippines, and South Africa)

Background

Studies relating childhood cognitive development to poor linear growth seldom take adequate account of social conditions related to both, leading to a focus on nutrition interventions. We aimed to assess the roles of both biological and social conditions in determining early childhood cognition, mediated by birthweight and early linear growth.

Methods

After exploratory structural equation modelling to identify determining factors, we tested direct and indirect paths to cognitive performance through birthweight and child height-for-age at 2 years, assessed between 4 and 8.5 years of age among 2448 children in four birth cohort studies in low-and-middle-income countries (Brazil, Guatemala, Philippines and South Africa). Determinants were compared across the cohorts.

Findings

Three factors yielded excellent fit, comprising birth endowment (primarily maternal age and birth order), household resources (crowding, dependency) and parental capacity (parental education). We estimated their strength together with maternal height in determining cognitive performance. Percentage shares of total effects of the four determinants show a marked transition from mainly biological determinants of birth weight (birth endowment 34%) and maternal height (30%) compared to household resources (25%) and parental capacity (11%), through largely economic determinants of height at 2 years (household resources (60%) to cognitive performance being predominantly determined by parental capacity (64%) followed by household resources (29%). The largely biological factor, birth endowment (maternal age and birth order) contributed only 7% to childhood cognitive performance and maternal height was insignificant. In summary, the combined share of social total effects (household resources and parental capacity) rises from 36∙2% on birth weight, to 78∙2% on height for age at 24 m, and 93∙4% on cognitive functioning.

Interpretation

Across four low- and middle-income contexts, cognition in childhood is influenced more by the parental capacity of families and their economic resources than by birth weight and early linear growth. Improving children's cognitive functioning requires multi-sectoral interventions to improve parental education and enhance their economic wellbeing, interventions that are known to improve also early childhood growth.

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We aimed to investigate separate and combined biological and social determination of young children’s cognitive performance.

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We used path analysis of longitudinal data from birth cohort studies in four differing low-and-middle countries.

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We distinguished biological and social factors, as well as household resources from parental capacity.

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Biological factors determine birthweight, 2-year height depends on social factors, and the latter drive child cognitive performance.

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No single domain intervention provides both necessary and sufficient support for young children’s unfolding development.

Relative Age and Attention-Deficit/Hyperactivity Disorder: Data From Three Epidemiological Cohorts and a Meta-analysis

OBJECTIVE

To investigate the effect of relatively younger age on attention-deficit/hyperactivity disorder (ADHD) symptoms and diagnosis through three population-based cohorts and a meta-analysis.

METHOD

This study included participants of three community-based cohorts in Brazil: 1993 Pelotas Cohort (N = 5,249), 2004 Pelotas Cohort (N = 4,231), and Brazilian High-Risk Study for Psychiatric Disorders (HRC study) (N = 2,511). We analyzed the effect of relatively younger age on ADHD symptoms and diagnosis. For the meta-analysis, we searched MEDLINE, PsycINFO, and Web of Science from inception through December 25, 2018. We selected studies that reported measures of association between relative immaturity and an ADHD diagnosis. We followed the Meta-analysis Of Observational Studies in Epidemiology guidelines. The protocol for meta-analysis is available on PROSPERO (CRD42018099966).

RESULTS

In the meta-analysis, we identified 1,799 potentially eligible records, from which 25 studies including 8,076,570 subjects (164,049 ADHD cases) were analyzed with their effect estimates. The summarized relative risk of an ADHD diagnosis was 1.34 (95% CI, 1.26-1.43, p < .001) for children born in the first 4 months of the school year (relatively younger). Heterogeneity was high (I² = 96.7%). Relative younger age was associated with higher levels of ADHD symptoms in the 1993 Pelotas Cohort (p = .003), 2004 Pelotas Cohort (p = .046), and HRC study (p = .010).

CONCLUSION

Children and adolescents who are relatively younger compared with their classmates have a higher risk of receiving an ADHD diagnosis. Clinicians should consider the developmental level of young children when evaluating ADHD symptoms.

Characterisation of pulmonary function trajectories: results from a Brazilian cohort

BACKGROUND

Pulmonary function (PF) trajectories are determined by different exposures throughout the life course. The aim of this study was to investigate characteristics related to PF trajectories from 15 to 22 years in a Brazilian cohort.

METHODS

A birth cohort study (1993 Pelotas Birth Cohort) was conducted with spirometry at 15, 18 and 22 years. PF trajectories were built based on z-score of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and their ratio using a group-based trajectory model. Associations with exposures reported from perinatal to 22 years were described.

RESULTS

Three trajectories, low (LT), average (AT) and high (HT) were identified in 2917 individuals. Wealthiest individuals belonged to the HT of FEV1 (p=0.023). Lower maternal pregestational body mass index (BMI) (22.4±0.2; p<0.001 and 22.1±0.14; p<0.001) and lower birth weight (3164.8±25.4; p=0.029 and 3132.3±19.4; p=0.005) were related to the LT of FEV1 and FVC. Mother's smoking exposure during pregnancy (37.7%; p=0.002), active smoking at ages 18 and 22 years (20.1% and 25.8%; p<0.001) and family history of asthma (44.8%; p<0.001) were related to the LT of FEV1/FVC. Wheezing, asthma and hospitalisations due to respiratory diseases in childhood were related to the LT of both FEV1 and FEV1/FVC. Higher BMIs were related to the HT of FEV1 and FVC at all ages.

CONCLUSIONS

PF trajectories were mainly related to income, pregestational BMI, birth weight, hospitalisation due to respiratory diseases in childhood, participant's BMI, report of wheezing, medical diagnosis and family history of asthma, gestational exposure to tobacco and current smoking status in adolescence and young adult age.

Revisiting ADHD age-of-onset in adults: to what extent should we rely on the recall of childhood symptoms?

BACKGROUND

ADHD diagnosis requires the presence of symptoms before the age of twelve. In clinical assessment of adults, the most frequent strategy to check this criterion is investigating self-report recall of symptoms, despite little evidence on the validity of this approach. We aim to evaluate the recall accuracy and factors associated with its reliability in a large population-based sample of adults.

METHODS

Individuals from the 1993 Pelotas Birth Cohort were followed-up from childhood to adulthood. At the age of 22, 3810 individuals were assessed through structured interviews by trained psychologists regarding mental health outcomes, including ADHD diagnosis and ADHD symptoms in childhood. The retrospective recall was compared with available information on ADHD childhood symptoms at the age of eleven. We also assessed factors related to recall accuracy through multiple regression analyses.

RESULTS

Self-reported recall of childhood symptoms at 22 years of age had an accuracy of only 55.4%, with sensitivity of 32.8% and positive predictive value of 40.7%. Current inattention symptoms were associated with lower risk and social phobia with higher risk for false-positive endorsement, while higher levels of schooling correlated with lower risk and male gender with higher risk for false-negative endorsement.

CONCLUSIONS

Clinicians treating male patients with social phobia and ADHD symptoms should assess even more carefully retrospective recall of ADHD childhood symptoms. Moreover, characteristics associated with recall improvement do not impact accuracy robustly. In this context, the recall of childhood ADHD symptoms seems an unreliable method to characterize the neurodevelopmental trajectory in adults with currently-impairing ADHD symptomatology.

Mental disorders in adolescents, youth, and adults in the RPS Birth Cohort Consortium (Ribeirão Preto, Pelotas and São Luís), Brazil

Although depression and anxiety are known to result in disabilities and workplace and health system losses, population-based studies on this problem are rare in Brazil. The current study assessed the prevalence of mental disorders in adolescents, youth, and adults and the relationship to sociodemographic characteristics in five birth cohorts (RPS) in Ribeirão Preto (São Paulo State), Pelotas (Rio Grande do Sul State), and São Luís (Maranhão State), Brazil. Major depressive episode, suicide risk, social phobia, and generalized anxiety disorder were assessed with the Mini International Neuropsychiatric Interview. Bootstrap confidence intervals were estimated and prevalence rates were stratified by sex and socioeconomic status in the R program. The study included 12,350 participants from the cohorts. Current major depressive episode was more prevalent in adolescents in São Luís (15.8%; 95%CI: 14.8-16.8) and adults in Ribeirão Preto (12.9%; 95%CI: 12.0-13.9). The highest prevalence rates for suicide risk were in adults in Ribeirão Preto (13.7%; 95%CI: 12.7-14.7), and the highest rates for social phobia and generalized anxiety were in youth in Pelotas, with 7% (95%CI: 6.3-7.7) and 16.5% (95%CI: 15.4-17.5), respectively. The lowest prevalence rates of suicide risk were in youth in Pelotas (8.8%; 95%CI: 8.0-9.6), social phobia in youth in Ribeirão Preto (1.8%; 95%CI: 1.5-2.2), and generalized anxiety in adolescents in São Luís (3.5%; 95%CI: 3.0-4.0). Mental disorders in general were more prevalent in women and in individuals with lower socioeconomic status, independently of the city and age, emphasizing the need for more investment in mental health in Brazil, including gender and socioeconomic determinants.

Growth from birth to adolescence and bone mineral density in young adults: The 1993 Pelotas birth cohort

BACKGROUND

The study examined the association of body size (weight and length) at birth and gain in height and weight during childhood and adolescence with areal bone mineral density (aBMD) in adulthood for women and men.

METHODS

756 members (335 men and 421 women) of the 1993 Pelotas (Brazil) Birth cohort were studied. Data on weight and length/height were obtained at birth and subsequent follow-ups at 1, 4, 11, 15, 18, and 22 years of age and specific z scores were calculated by sex. The outcome was whole body aBMD (g/cm²) measured at 22 years of age using dual-energy X-ray absorptiometry (DXA). The effects of exposures, weight and length/height gain, were analyzed using conditional relative weight (CWh) and conditional length/height (CH). Linear regression models were adjusted for multiple confounders, including mother's educational level, family income, maternal smoking during pregnancy, gestational age, breastfeeding and skin color.

RESULTS

In the adjusted models, among men greater height gain at 4, 11, and 18 years of age was associated with higher whole body aBMD, and the result with greatest magnitude was at 11 years of age (β 0.018 g/cm²; 95%CI 0.006; 0.030). Among women, aBMD was associated with height gain at all assessments from 1-15 years, with greatest effect size at 4 years of age (β 0.017 g/cm²; 95%CI 0.007; 0.027). Regarding to body weight, among men, greater weight at 4 and 15 years were associated with higher aBMD, with the highest coefficients for 15 years of age (β 0.015 g/cm²; 95%CI 0.003; 0.027); for women, except at birth, all weight gain variables were associated with aBMD and the highest coefficients were observed at 4 years (β 0.025 g/cm²; 95%CI 0.015; 0.035).

CONCLUSIONS

In this birth cohort, height and weight gain, especially from 4 to 15 years have important positive implications for aBMD to early adulthood.