Letícia Marques dos Santos

Determinants of cognitive function in childhood: A cohort study in a middle income context

BackgroundThere is evidence that poverty, health and nutrition affect childrens cognitive development. This study aimed to examine the relative contributions of both proximal and distal risk factors on child cognitive development, by breaking down the possible causal pathways through which poverty affects cognition.MethodsThis cohort study collected data on family socioeconomic status, household and neighbourhood environmental conditions, child health and nutritional status, psychosocial stimulation and nursery school attendance. The effect of these on Wechsler Pre-School and Primary Scale of Intelligence scores at five years of age was investigated using a multivariable hierarchical analysis, guided by the proposed conceptual framework.ResultsUnfavourable socioeconomic conditions, poorly educated mother, absent father, poor sanitary conditions at home and in the neighbourhood and low birth weight were negatively associated with cognitive performance at five years of age, while strong positive associations were found with high levels of domestic stimulation and nursery school attendance.ConclusionChildrens cognitive development in urban contexts in developing countries could be substantially increased by interventions promoting early psychosocial stimulation and preschool experience, together with efforts to prevent low birth weight and promote adequate nutritional status.

Behavior problems and prevalence of asthma symptoms among Brazilian children.

Objective Asthma is the most common chronic disease in childhood and has been designated a public health problem due to the increase in its prevalence in recent decades, the amount of health service expenditure it absorbs and an absence of consensus about its etiology. The relationships among psychosocial factors and the occurrence, symptomatology, and severity of asthma have recently been considered. There is still controversy about the association between asthma and a childs mental health, since the pathways through which this relationship is established are complex and not well researched. This study aims to investigate whether behavior problems are associated with the prevalence of asthma symptoms in a large urban center in Latin America. Methods It is a cross-section study of 869 children between 6 and 12 years old, residents of Salvador, Brazil. The International Study of Allergy and Asthma in Childhood (ISAAC) instrument was used to evaluate prevalence of asthma symptoms. The Child Behavior Checklist (CBCL) was employed to evaluate behavioral problems. Results 19.26% (n = 212) of the children presented symptoms of asthma. 35% were classified as having clinical behavioral problems. Poissons robust regression model demonstrated a statistically significant association between the presence of behavioral problems and asthma symptoms occurrence (PR: 1.43; 95% CI: 1.10–1.85). Conclusion These results suggest an association between behavioral problems and pediatric asthma, and support the inclusion of mental health care in the provision of services for asthma morbidity.

Determinants of early cognitive development: hierarchical analysis of a longitudinal study

The study describes the relationship between anthropometric status, socioeconomic conditions, and quality of home environment and child cognitive development in 320 children from 20 to 42 months of age, randomly selected from 20,000 households that represent the range of socioeconomic and environmental conditions in Salvador, Bahia, Northeast Brazil. The inclusion criterion was to be less than 42 months of age between January and July 1999. Child cognitive development was assessed using the Bayley Scales for Infant Development, and the Home Observation for Measurement of the Environment Inventory (HOME) was applied to assess quality of home environment. Anthropometric status was measured using the indicators weight/age and height/age ratios (z-scores), and socioeconomic data were collected through a standard questionnaire. Statistical analysis was conducted through univariate and hierarchical linear regression. Socioeconomic factors were found to have an indirect impact on early cognitive development mediated by the childs proximal environment factors, such as appropriate play materials and games available and school attendance. No independent association was seen between nutritional status and early cognitive development.

Structural equation modeling in epidemiology

Structural equation modeling (SEM) is an important statistical tool for evaluating complex relations in several research areas. In epidemiology, the use and discussion of SEM have been limited thus far. This article presents basic principles and concepts in SEM, including an application using epidemiological data analysis from a study on the determinants of cognitive development in young children, considering constructs related to organization of the childs home environment, parenting style, and the childs health status. The relations between the constructs and cognitive development were measured. The results showed a positive association between psychosocial stimulus at home and cognitive development in young children. The article presents the contributions by SEM to epidemiology, highlighting the need for an a priori theoretical model for improving the study of epidemiological questions from a new perspective.

Maternal mental health and social support: effect on childhood atopic and non-atopic asthma symptoms

Background Atopic and non-atopic asthma have distinct risk factors and immunological mechanisms, and few studies differentiate between the impacts of psychosocial factors on the prevalence of these disease phenotypes. The authors aimed to identify whether the effect of maternal mental health on prevalence of asthma symptoms differs between atopic and non-atopic children, taking into account family social support. Methods This is a cross-sectional study of 1013 children participating in the Social Change Allergy and Asthma in Latin America project. Psychosocial data were collected through a household survey utilising Self-Reporting Questionnaire and Medical Outcome Study Social Support Scale. Socioeconomic and wheezing information was obtained through the questionnaire of the International Study of Allergy and Asthma in Childhood, and level of allergen-specific IgE was measured to identify atopy. Polytomous logistic regression was used to estimate the association between maternal mental health, social support and atopic and non-atopic wheezing. Effect modification was evaluated through stratified polytomous regression according to social support level. Results Maternal mental disorder had the same impact on atopic and non-atopic wheezing, even after adjusting for confounding variables. Affective, material and informational supports had protective effects on non-atopic asthma, and there is some evidence that social supports may act as a buffer for the impact of maternal mental disorder on non-atopic wheezing. Conclusion Poor maternal mental health is positively associated with wheezing, independent of whether asthma is atopic or non-atopic, but perception of high levels of social support appears to buffer this relationship in non-atopic wheezers only.

Prevalence of behavior problems and associated factors in preschool children from the city of Salvador, state of Bahia, Brazil

Objective: To identify the prevalence of internalizing and externalizing behavior problems among preschoolers from the city of Salvador, state of Bahia, Brazil, and their associations with maternal mental health and family characteristics. Methods: This was a cross-sectional study of 349 children aged 49 to 72 months, randomly selected from 20,000 households representing the range of socioeconomic and environmental conditions in Salvador. In 1999, we assessed sociodemographic variables and family environment characteristics. In 2001, we used the Child Behavior Checklist to measure and describe the frequencies of behavior problems. We conducted bivariate and multivariate analysis to estimate associations between family and maternal factors and prevalence of behavior problems. Results: The overall prevalence of behavior problems was 23.5%. The prevalence of internalizing problems was 9.7%, and that of externalizing problems, 25.2%. Behavior problems were associated with several maternal mental health variables, namely: presence of at least one psychiatric diagnosis (odds radio [OR] 3.01, 95%CI 1.75-5.18), anxiety disorder (OR 2.06, 95%CI 1.20-3.46), affective disorder (OR 2.10, 95%CI 1.21-3.65), and mental health disorders due to use of psychoactive substances (OR 2.31, 95%CI 1.18-4.55). Conclusion: The observed prevalence of child behavior problems fell within the range reported in previous studies. Maternal mental health is an important risk factor for behavior problems in preschool-aged children.

Influência da violência familiar na associação entre desnutrição e baixo desenvolvimento cognitivo

OBJECTIVES To investigate the size and direction of the association between malnutrition and low cognitive performance and to evaluate the effect of domestic violence on this association. METHODS This cross-sectional study enrolled students of both sexes, aged 7 to 14 years old, attending public elementary schools. The Ravens Progressive Matrices Test was used to measure cognitive development, the Revised Conflict Tactics Scales (CTS2), to measure domestic violence, and the body mass index (BMI) for age and sex, to define anthropometric indices. Socioeconomic data and information about food intake were also collected. Malnutrition was defined as BMI < 3rd percentile. Cognitive deficit was defined when the results of Ravens test were ≤ 25th percentile. Family violence was defined as a positive answer in at least one item about severe physical violence in the last 12 months. The size of the associations of interest was expressed as prevalence ratio (PR) and 95% confidence interval (95%CI). RESULTS Below-average intellectual development was found for 63.3% of the participants. Malnutrition was identified in 9.5%. Malnutrition had a negative effect on cognitive performance (adjusted prevalence ratio [aPR] = 1.60, 95% CI = 1.01 - 2.52; p = 0.042) when adjusted for the association between exposure to domestic violence and age. CONCLUSION The association between malnutrition and below-average intellectual development found in this study was affected by domestic violence, which must be taken into account when addressing the problem.

Personal-Level and Group-Level Discrimination and Mental Health: the Role of Skin Color

ObjectiveThis study investigates the association between personal-level and group-level discrimination and common mental disorders (CMDs) among Afro-Brazilian women, aiming to explore the role of skin color on this association.MethodsThis is a cross-sectional study involving 1130 women who were participating in the Social Change, Asthma and Allergy in Latin America (SCAALA) study, whose children were recruited from 24 geographical micro-regions representative of the population without sanitation. Measures of discrimination were defined by: experiences (personal-level) and concern about discrimination (group-level) using the Experiences of Discrimination Scale. Skin color was registered by self-declaration, being classified as white, brown, and black. The association between “self-reported” discrimination and CMDs was evaluated using Poisson regression analysis.ResultsPrevalence of CMDs was high (38.3%), especially in the group exposed to discriminatory experiences and black women. Experiences and concern about discrimination were positive and significantly associated with mental health, before and after adjustment for potential confounders. The effect of discrimination on CMDs was lower among black women, suggesting the development of other strategies to confront racism.ConclusionThis study emphasizes the use of both personal- and group-level discrimination measures, as well as skin color, for the evaluation of mental disorders in public health research. Further studies of health consequences of discrimination will require investigation of protective factors for mental disorders in the population suffering discrimination and racism.

Screening for common mental disorders using the SRQ-20 in Brazil: what are the alternative strategies for analysis?

Objective: To analyze the prevalence of common mental disorders (CMD) assessed with the Self Reporting Questionnaire (SRQ-20), using the established cutoff point, and comparing it with the results of a joint correspondence factor analysis (CFA) and cluster analysis and of a latent class analysis (LCA). Methods: A cross-sectional study was carried out in an urban sample of 1,095 women aged 19 to 55 years. Joint CFA-cluster analysis and LCA were used. Results: We found a high prevalence of CMD, regardless of classification method (37.6% when using the cutoff point; 44.4% and 52% for LCA and joint CFA-cluster, respectively). The alternative analysis strategies describe the cases more efficiently when compared to the traditional cutoff method, especially regarding more severe symptoms. Both alternative strategies also provide a description of the SRQ-20 dimensions in their particularities, which may be useful for the planning and implementation of specific actions in a given population. Conclusion: The SRQ-20 cutoff point seems to underestimate the magnitude of CMD among women. The alternative methods of analysis presented herein highlight the different possibilities of using this important instrument of screening for mental health.

Validez del constructo de la escala Experiences of Discrimination en una población brasileña

Um dos instrumentos mais utilizados na pesquisa epidemiologica sobre discriminacao e o Experiences of Discrimination (EOD), utilizada no Brasil, porem nao validado. O objetivo foi avaliar a confiabilidade e estrutura dimensional da escala EOD em uma populacao brasileira. Foi conduzido um estudo transversal com 1.380 adultos da cidade de Salvador, Bahia, Brasil. Realizou-se analise fatorial confirmatoria (AFC) testando um modelo de dois fatores: experiencia de discriminacao e preocupacao por discriminacao. Os resultados da AFC mostraram parâmetros satisfatorios de ajuste, elevadas cargas fatoriais e valores adequados de confiabilidade, confirmando a consistencia interna da escala. Identificaram-se correlacoes residuais envolvendo itens de ambos os fatores. A estrutura dimensional apresentada neste estudo destaca a importância de utilizar diferentes medidas de discriminacao - interpessoais e grupais - que permitam em estudos futuros aprofundar nos efeitos do racismo sobre a saude