RESUMEN
We examined prospective cohort studies evaluating the relation between prenatal and neonatal exposure to polychlorinated biphenyls (PCBs) and neurodevelopment in children to assess the feasibility of conducting a meta-analysis to support decision making. We described studies in terms of exposure and end point categorization, statistical analysis, and reporting of results. We used this evaluation to assess the feasibility of grouping studies into reasonably uniform categories. The most consistently used tests included Brazelton's Neonatal Behavioral Assessment Scale, the neurologic optimality score in the neonatal period, the Bayley Scales of Infant Development at 5-8 months of age, and the McCarthy Scales of Children's Abilities in 5-year-olds. Despite administering the same tests at similar ages, the studies were too dissimilar to allow a meaningful quantitative examination of outcomes across cohorts. These analyses indicate that our ability to conduct weight-of-evidence assessments of the epidemiologic literature on neurotoxicants may be limited, even in the presence of multiple studies, if the available study methods, data analysis, and reporting lack comparability.
Asunto(s)
Sistema Nervioso/efectos de los fármacos , Sistema Nervioso/crecimiento & desarrollo , Síndromes de Neurotoxicidad/etiología , Bifenilos Policlorados/efectos adversos , Preescolar , Toma de Decisiones , Humanos , Lactante , Recién Nacido , Masculino , Metaanálisis como Asunto , Literatura de Revisión como AsuntoRESUMEN
We examined prospective cohort studies evaluating the relation between prenatal and neonatal exposure to polychlorinated biphenyls (PCBs) and neurodevelopment in children to assess the feasibility of conducting a meta-analysis to support decision making. We described studies in terms of exposure and end point categorization, statistical analysis, and reporting of results. We used this evaluation to assess the feasibility of grouping studies into reasonably uniform categories. The most consistently used tests included Brazelton's Neonatal Behavioral Assessment Scale, the neurologic optimality score in the neonatal period, the Bayley Scales of Infant Development at 5-8months of age, and the McCarthy Scales of Children's Abilities in 5-year-olds. Despite administering the same tests at similar ages, the studies were too dissimilar to allow a meaningful quantitative examination of outcomes across cohorts. These analyses indicate that our ability to conduct weight-of-evidence assessments of the epidemiologic literature on neurotoxicants may be limited, even in the presence of multiple studies, if the available study methods, data analysis, and reporting lack comparability.
Foram examinados estudos de grupo que avaliaram a relação entre a exposição pré-natal e neonatal aos bifenilos policlorados (PCB) e o desenvolvimento neuropsicomotor em crianças a fim de avaliar a viabilidade da realização de uma meta-análise para suporte à tomada de decisão. Nós descrevemos os estudos em termos de exposição, categorizações, análise estatística e elaboração de relatórios de resultados. Nós utilizamos esta avaliação para verificar a viabilidade de agrupar os estudos em categorias razoavelmente uniformes. Os testes mais utilizados foram Brazelton Neonatal Behavioral Assessment Scale, a pontuação de otimalidade neurológica no período neonatal, as Escalas Bayley de Desenvolvimento Infantil de 5 a 8 meses de idade, e as Escalas McCarthy de habilidades das crianças em 5 anos de idade. Apesar de administrar os mesmos testes com idades semelhantes, os estudos foram muito diferentes para permitir uma análise quantitativa significativa dos resultados entre grupos. Estas análises indicam que a nossa capacidade de realizar avaliações da literatura epidemiológica sobre neurotóxicos pode ser limitada - mesmo na presença de vários estudos - se não existe nenhuma forma de comparação com os métodos de estudo disponíveis e análise dos dados.
Asunto(s)
Preescolar , Humanos , Lactante , Recién Nacido , Masculino , Sistema Nervioso/efectos de los fármacos , Sistema Nervioso/crecimiento & desarrollo , Síndromes de Neurotoxicidad/etiología , Bifenilos Policlorados/efectos adversos , Toma de Decisiones , Metaanálisis como Asunto , Literatura de Revisión como AsuntoRESUMEN
OBJECTIVE: To determine the medical and neurodevelopmental outcome of children with moderately severe persistent pulmonary hypertension of the newborn (PPHN) treated with or without inhaled nitric oxide (I-NO). STUDY DESIGN: Term infants with PPHN and a baseline oxygenation index of 24 +/- 9 at study entry were randomly assigned to early treatment with placebo or initial doses of I-NO (5, 20, and 80 ppm). Outcome was measured at approximately 1 year by frequency of hospitalization, growth, and neurodevelopmental and audiologic evaluation. RESULTS: Of 155 children enrolled, 144 survived, and there was follow-up for 133. No significant differences between the placebo and the I-NO groups were seen in any long-term outcome. Rehospitalization occurred in 22%, and growth did not differ. The composite neurodevelopment and audiologic outcome showed impairment in 46% of the infants. There were major neurologic abnormalities in 13%, cognitive delays in 30%, and hearing loss in 19% of the infants. CONCLUSIONS: Moderately severe PPHN at 24 hours after birth is associated with high rates of rehospitalization and disability at 1 year. Adverse outcomes were the same in I-NO and control groups.