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Predicting childhood blood lead levels (BLLs) has had mixed success, and it is unclear if individual- or neighborhood-level variables are most predictive. An ensemble machine learning (ML) approach to identify the most relevant predictors of BLL ≥2µg/dL in urban children was implemented. A cross-sectional sample of 603 children (~7 years of age) recruited between 2009-2019 from Montevideo, Uruguay participated in the study. 77 individual- and 32 neighborhood-level variables were used to predict BLLs ≥2µg/dL. Three ensemble learners were created: one with individual-level predictors (Ensemble-I), one with neighborhood-level predictors (Ensemble-N), and one with both (Ensemble-All). Each ensemble learner comprised four base classifiers with 50% training, 25% validation, and 25% test datasets. Predictive performance of the three ensemble models was compared using area under the curve (AUC) for the receiver operating characteristic (ROC), precision, sensitivity, and specificity on the test dataset. Ensemble-I (AUC: 0.75, precision: 0.56, sensitivity: 0.79, specificity: 0.65) performed similarly to Ensemble-All (AUC: 0.75, precision: 0.63, sensitivity: 0.79, specificity: 0.69). Ensemble-N (AUC: 0.51, precision: 0.0, sensitivity: 0.0, specificity: 0.50) severely underperformed. Year of enrollment was most important in Ensemble-I and Ensemble-All, followed by household water Pb. Three neighborhood-level variables were among the top 10 important predictors in Ensemble-All (density of bus routes, dwellings with stream/other water source and distance to nearest river). The individual-level only model performed best, although precision was improved when both neighborhood and individual-level variables were included. Future predictive models of lead exposure should consider proximal predictors (i.e., household characteristics).
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PURPOSE: The benefits of a healthy diet on children´s cognition have been described in several studies. However, many previous studies have analyzed the effect on general cognitive domains (e.g. intelligence), used measures based almost exclusively on local examinations, and rarely consider social context. OBJECTIVE: The objective of the present study was to examine the relationship between two diet patterns and contextualized cognitive performance measures of children aged 6-8 years from low-average income neighborhoods in Montevideo, Uruguay. METHODS: 270 first-grade children with complete data participated in the study. Consumption of foods was determined via two averaged 24-h dietary recalls with the mother. Two dietary patterns were identified via principal component analysis: "processed (high calorie) foods" and "nutrient dense". Children´s cognitive performance, including general cognitive abilities, achievement in mathematics and reading, and discrepancy scores between predicted and actual achievement was assessed with the Woodcock-Muñoz Cognitive and Achievement scales. The association of dietary patterns and cognitive endpoints was analyzed in multilevel models, clustered by children´s school. Sociodemographic and biological variables were used as covariates. RESULTS: The nutrient dense foods pattern, characterized by higher consumption of dark leafy and red-orange vegetables, eggs, beans & peas, potatoes, was associated with better performance in reading, with beta coefficient 3.28 (95% CI 0.02, 6.54). There was also an association between the nutrient dense foods factor and the Discrepancy in reading, 2.52 (0.17, 4.87). Processed (high calorie) foods pattern, characterized by higher consumption of breads, processed meats, fats and oils, sweetened beverages, and sweetened yogurt/dairy products; reduced intake of milk, pastries and pizza dinners was not associated with cognitive performance. CONCLUSIONS: Nutrient dense food pattern was positively associated with children's reading achievement. A nutrient-rich diet may benefit written language acquisition at the beginning of schooling.
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Dieta , Ingestión de Energía , Humanos , Niño , Uruguay , Verduras , CogniciónRESUMEN
ABSTRACT Background: The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) has been recently developed as a brief, practical, and feasible tool for cognitive impairment in multiple sclerosis (MS). Objective: This study aimed to provide continuous and discrete normative values for the BICAMS in the Brazilian context. Methods: Normatization was achieved using six hundred and one healthy controls from the community assessed at five Brazilian geopolitical regions. Results: Mean raw scores, T scores, percentiles, and Z scores for each BICAMS measure are provided, stratified by age and educational level. Regression-based norms were provided by converting raw scores to scaled scores, which were regressed on age, gender, and education, yielding equations that can be used to calculate the predicted scores. Regression analyses revealed that age, gender, and education significantly influenced test results, as in previous studies. Conclusions: The normative data of the BICAMS to the Brazilian context presented good representativeness, improving its use in daily clinical practice.
RESUMO Antecedentes: O BICAMS foi desenvolvido como uma ferramenta breve, prática e confiável para avaliar o comprometimento cognitivo na esclerose múltipla (EM). Objetivo: Neste estudo, objetivamos fornecer dados normativos para o BICAMS. Métodos: Normatização foi realizada com seiscentos e um controles saudáveis da comunidade avaliados das cinco regiões geopolíticas brasileiras. Resultados: Escores brutos médios, escore T, percentil e escore Z para cada medida do BICAMS são fornecidos e estratificados por idade e nível educacional. Normas baseadas em regressão foram obtidas através da conversão dos pontos brutos em pontos ponderados, produzindo parâmetros de regressão que podem ser usados para calcular os escores preditos. As análises de regressão revelaram que idade, gênero e educação influenciaram significativamente nos resultados do teste, assim como em estudos prévios. Conclusão: Normas do BICAMS para o contexto brasileiro apresentaram boa representatividade, contribuindo para a utilização na prática clínica diária.
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Humanos , Disfunción Cognitiva/diagnóstico , Esclerosis Múltiple/psicología , Brasil , Reproducibilidad de los Resultados , Cognición , Pruebas NeuropsicológicasRESUMEN
BACKGROUND: The Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS) has been recently developed as a brief, practical, and feasible tool for cognitive impairment in multiple sclerosis (MS). OBJECTIVE: This study aimed to provide continuous and discrete normative values for the BICAMS in the Brazilian context. METHODS: Normatization was achieved using six hundred and one healthy controls from the community assessed at five Brazilian geopolitical regions. RESULTS: Mean raw scores, T scores, percentiles, and Z scores for each BICAMS measure are provided, stratified by age and educational level. Regression-based norms were provided by converting raw scores to scaled scores, which were regressed on age, gender, and education, yielding equations that can be used to calculate the predicted scores. Regression analyses revealed that age, gender, and education significantly influenced test results, as in previous studies. CONCLUSIONS: The normative data of the BICAMS to the Brazilian context presented good representativeness, improving its use in daily clinical practice.
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Disfunción Cognitiva , Esclerosis Múltiple , Brasil , Cognición , Disfunción Cognitiva/diagnóstico , Humanos , Esclerosis Múltiple/psicología , Pruebas Neuropsicológicas , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: Neighborhood disadvantage (ND) is a risk factor for child behavior problems (CBPs), but is understudied outside the United States and Europe. Our mixed methods study aims to (1) create a culturally meaningful measure of ND, (2) test cross-sectional associations between ND and CBPs and (3) qualitatively explore life in the neighborhoods of families participating in the Salud Ambiental Montevideo (SAM) study. METHODS: The quantitative study (Study 1) comprised 272, ~7-year-old children with geolocation and complete data on twelve behavioral outcomes (Conner's Teachers Rating Scale - Revised Short Form: CTRS-R:S and Behavioral Rating Inventory of Executive Functioning: BRIEF). A ND factor was created at the census segment level (1,055 segments) with 19 potential indicators of ND downloaded from the Municipality of Montevideo Geographic Services. Children were assigned ND scores based on the location of their household within a census segment. Multilevel models tested associations between ND and all CBP scales, controlling for confounders at the individual level. The qualitative study (Study 2) comprised 10 SAM caregivers. Photovoice alongside semi-structured interviews in Spanish were used to foster conversations about neighborhood quality, activities, and raising children. Thematic analysis with inductive coding was used to summarize qualitative study findings. RESULTS: The ND factor consisted of 12 census-based indicators related to education, employment, ethnicity, housing quality, and age characteristics, but unrelated to home ownership and some ethnicity variables. In multivariable models, ND was associated with greater conduct problems (ß = 1.37, p < .05), poor shifting (ß = 1.56, p < .01) and emotional control problems (ß = 2.36, p < .001). Photovoice and semi-structured interviews yielded four themes: physical disorder, recreation, safety and crime, and community resources. Residents discussed improving waste management and transportation, updating playgrounds, and ensuring neighborhood safety. CONCLUSIONS: ND in Montevideo comprised a unique set of census indicators. ND was primarily related to behavioral regulation problems. Hypothesized pathways whereby ND affects CBPs are discussed.
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Problema de Conducta , Características de la Residencia , Niño , Estudios Transversales , Etnicidad , Humanos , Estados Unidos , UruguayRESUMEN
OBJECTIVES: Lead (Pb) and manganese (Mn) are confirmed neurotoxins but it is unclear to what extent low-level exposure produces a unique behavioral signature. The objective of this study was to investigate latent cognitive profiles among children (6-8 years) from Montevideo, Uruguay co-exposed to these metals. METHOD: Among 345 children, blood Pb and hair Mn were measured using atomic absorption spectroscopy and ICP-MS, respectively. Sixteen measures, reflecting multiple domains of cognitive functioning were gathered: (1) three tests from Cambridge Neuropsychological Test Automated Battery (CANTAB): Intra-Extra Dimensional Shift (IED), Spatial Span (SSP) and Stockings of Cambridge (SOC), (2) ten tasks from Woodcock-Muñoz Achievement Battery, Revised (WM): Visual-Motor Integration, Verbal Comprehension (Vocabulary, Synonyms, Antonyms, Analogies), Visual-Auditory Comprehension, Concept Formation, Visual Spatial Thinking, Number Inversion and Spatial Relations, (3) Bender Gestalt task, and (4) Weschler block design task. Scores were modeled using latent profile analysis (LPA). Association between blood Pb and hair Mn on performance profiles was assessed using ordinal regression, controlling for confounders. An interaction between Pb and Mn was tested. RESULTS: Mean ± SD of blood Pb was 4.1 ± 2.1 µg/dL and 35% of children had blood Pb ≥ 5 µg/dL. Median [5%, 95%] hair Mn level was 0.8 [0.3, 4.1] ppb. Three latent cognitive performance profiles were identified: high (n = 46, 13%), average (n = 209, 61%) and low (n = 90, 26%). Each one-unit increase in blood Pb was associated with a 28% greater likelihood of belonging to a poorer-performing profile. The association was non-linear, with the effect of Pb on profile membership strongest at lower levels of exposure. There was no meaningful interaction between Pb and Mn. CONCLUSIONS: A behavioral signature for low-level Pb & Mn exposure was not identified, but the likelihood of membership in low-performing profile was higher at lowest levels of blood Pb. There was no effect measure modification between Pb and Mn. Future research should address how complex environments created by chemical exposures and the social context relate to cognitive performance in young children.
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Conducta Infantil/efectos de los fármacos , Desarrollo Infantil/efectos de los fármacos , Cognición/efectos de los fármacos , Exposición a Riesgos Ambientales/efectos adversos , Contaminantes Ambientales/efectos adversos , Intoxicación del Sistema Nervioso por Plomo en la Infancia/psicología , Plomo/efectos adversos , Intoxicación por Manganeso/psicología , Manganeso/efectos adversos , Factores de Edad , Carga Corporal (Radioterapia) , Niño , Estudios Transversales , Contaminantes Ambientales/análisis , Contaminantes Ambientales/sangre , Femenino , Cabello/química , Humanos , Plomo/sangre , Intoxicación del Sistema Nervioso por Plomo en la Infancia/sangre , Intoxicación del Sistema Nervioso por Plomo en la Infancia/diagnóstico , Intoxicación del Sistema Nervioso por Plomo en la Infancia/etiología , Masculino , Manganeso/análisis , Intoxicación por Manganeso/sangre , Intoxicación por Manganeso/diagnóstico , Intoxicación por Manganeso/etiología , Medición de Riesgo , Factores de Riesgo , UruguayRESUMEN
OBJECTIVE: To investigate the reliability and validity of a Brazilian-Portuguese adaptation of the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS). METHOD: A Brazilian sample of 58 multiple sclerosis (MS) patients and 58 healthy controls (HC) were administered the Brazilian-Portuguese BICAMS test battery, comprising the Symbol Digit Modalities Test (SDMT), California Verbal Learning Test Second Edition (CVLT2), and the Brief Visuospatial Memory Test Revised (BVMTR). Mean differences between groups on BICAMS tests were assessed using analysis of covariance (ANCOVA), controlling for age, gender, education, anxiety, and depression. Test-retest data were obtained from 49 of the MS patients, two weeks after the initial assessment. RESULTS: The MS patient group scored significantly lower on all BICAMS tests (CVLT2 F1,110 = 28.99, p < .001; BVMTR F1,110 = 7.77, p < .01; SDMT F1,110 = 21.09, p < .001). Mixed-factor ANCOVAs tested differences in learning curves across trials for CVLT2 and BVMTR. HCs had significantly steeper learning curves on both CVLT2 (F1,111 = 10.82, p < .01) and BVMTR (F1,110 = 7.816, p < .01). These findings support diagnostic validity of the Brazilian-Portuguese adaptation. Test-retest reliability was satisfactory for SDMT, CVLT2, and BVMTR (.86, .84, and .77, respectively). CONCLUSION: The results suggest that this Brazilian version of the BICAMS will be a valid and reliable measure once complete normative data become available.