Neonatal mortality: description and effect of hospital of birth after risk adjustment

OBJECTIVE: To assess the effect of hospital of birth on neonatal mortality. METHODS: A birth cohort study was carried out in Pelotas, Southern Brazil, in 2004. All hospital births were assessed by daily visits to all maternity hospitals and 4558 deliveries were included in the study. Mothers were interviewed regarding potential risk factors. Deaths were monitored through regular visits to hospitals, cemeteries and register offices. Two independent pediatricians established the underlying cause of death based on information obtained from medical records and home visits to parents. Logistic regression was used to estimate the effect of hospital of birth, controlling for confounders related to maternal and newborn characteristics, according to a conceptual model. RESULTS: Neonatal mortality rate was 12.7‰ and it was highly influenced by birthweight, gestational age, and socioeconomic variables. Immaturity was responsible for 65% of neonatal deaths, followed by congenital anomalies, infections and intrapartum asphyxia. Adjusting for maternal characteristics, a three-fold increase in neonatal mortality was seen between similar complexity hospitals. The effect of hospital remained, though lower, after controlling for newborn characteristics. CONCLUSIONS: Neonatal mortality was high, mainly related to immaturity, and varied significantly across maternity hospitals. Further investigations comparing delivery care practices across hospitals are needed to better understand NMR variation and to develop strategies for neonatal mortality reduction.

Is adolescent pregnancy a risk factor for low birth weight?

OBJECTIVE: The objective of this study was to evaluate whether adolescent pregnancy is a risk factor for low birth weight (LBW) babies. METHODS: This was a cross-sectional study of mothers and their newborns from a birth cohort in Aracaju, Northeastern Brazil. Data were collected consecutively from March to July 2005. Information collected included socioeconomic, biological and reproductive aspects of the mothers, using a standardized questionnaire. The impact of early pregnancy on birth weight was evaluated by multiple logistic regression. RESULTS: We studied 4,746 pairs of mothers and their babies. Of these, 20.6% were adolescents (< 20 years of age). Adolescent mothers had worse socioeconomic and reproductive conditions and perinatal outcomes when compared to other age groups. Having no prenatal care and smoking during pregnancy were the risk factors associated with low birth weight. Adolescent pregnancy, when linked to marital status "without partner", was associated with an increased proportion of low birth weight babies. CONCLUSIONS: Adolescence was a risk factor for LBW only for mothers without partners. Smoking during pregnancy and lack of prenatal care were considered to be independent risk factors for LBW.

Correlates of C-reactive protein levels in young adults: a population-based cohort study of 3827 subjects in Brazil

The socio-demographic, behavioral and anthropometric correlates of C-reactive protein levels were examined in a representative young adult Brazilian population. The 1982 Pelotas Birth Cohort Study (Brazil) recruited over 99% of births in the city of Pelotas that year (N = 5914). Individuals belonging to the cohort have been prospectively followed up. In 2004-2005, 77.4% of the cohort was traced, members were interviewed and 3827 individuals donated blood. Analyses of the outcome were based on a conceptual model that differentiated confounders from potential mediators. The following independent variables were studied in relation to levels of C-reactive protein in sex-stratified analyses: skin color, age, family income, education, parity, body mass index, waist circumference, smoking, fat/fiber/alcohol intake, physical activity, and minor psychiatric disorder. Geometric mean (95% confidence interval) C-reactive protein levels for the 1919 males and 1908 females were 0.89 (0.84-0.94) and 1.96 mg/L (1.85-2.09), respectively. Pregnant women and those using oral contraceptive therapies presented the highest C-reactive protein levels and all sub-groups of women had higher levels than men (P < 0.001). Significant associations between C-reactive protein levels were observed with age, socioeconomic indicators, obesity status, smoking, fat and alcohol intake, and minor psychiatric disorder. Associations were stronger at higher levels of C-reactive protein and some associations were sex-specific. We conclude that both distal (socio-demographic) and proximal (anthropometric and behavioral) factors exert strong effects on C-reactive protein levels and that the former are mediated to some degree by the latter.

Evaluation of the cumulative evidence for freedom from BSE in birth cohorts

Substantial resources are used for surveillance of bovine spongiform encephalopathy (BSE) despite an extremely low detection rate, especially in healthy slaughtered cattle. We have developed a method based on the geometric waiting time distribution to establish and update the statistical evidence for BSE-freedom for defined birth cohorts using continued surveillance data. The results suggest that currently (data included till September 2004) a birth cohort of Danish cattle born after March 1999 is free from BSE with probability (power) of 0.8746 or 0.8509, depending on the choice of a model for the diagnostic sensitivity. These results apply to an assumed design prevalence of 1 in 10,000 and account for prevalence heterogeneity. The age-dependent, diagnostic sensitivity for the detection of BSE has been identified as major determinant of the power. The incorporation of heterogeneity was deemed adequate on scientific grounds and led to improved power values. We propose our model as a decision tool for possible future modification of the BSE surveillance and discuss public health and international trade implications.

European birth cohorts for environmental health research

Many pregnancy and birth cohort studies investigate the health effects of early-life environmental contaminant exposure. An overview of existing studies and their data is needed to improve collaboration, harmonization, and future project planning.

Preterm birth, infant weight gain, and childhood asthma risk: A meta-analysis of 147,000 European children

BACKGROUND Preterm birth, low birth weight, and infant catch-up growth seem associated with an increased risk of respiratory diseases in later life, but individual studies showed conflicting results. OBJECTIVES We performed an individual participant data meta-analysis for 147,252 children of 31 birth cohort studies to determine the associations of birth and infant growth characteristics with the risks of preschool wheezing (1-4 years) and school-age asthma (5-10 years). METHODS First, we performed an adjusted 1-stage random-effect meta-analysis to assess the combined associations of gestational age, birth weight, and infant weight gain with childhood asthma. Second, we performed an adjusted 2-stage random-effect meta-analysis to assess the associations of preterm birth (gestational age <37 weeks) and low birth weight (<2500 g) with childhood asthma outcomes. RESULTS Younger gestational age at birth and higher infant weight gain were independently associated with higher risks of preschool wheezing and school-age asthma (P < .05). The inverse associations of birth weight with childhood asthma were explained by gestational age at birth. Compared with term-born children with normal infant weight gain, we observed the highest risks of school-age asthma in children born preterm with high infant weight gain (odds ratio [OR], 4.47; 95% CI, 2.58-7.76). Preterm birth was positively associated with an increased risk of preschool wheezing (pooled odds ratio [pOR], 1.34; 95% CI, 1.25-1.43) and school-age asthma (pOR, 1.40; 95% CI, 1.18-1.67) independent of birth weight. Weaker effect estimates were observed for the associations of low birth weight adjusted for gestational age at birth with preschool wheezing (pOR, 1.10; 95% CI, 1.00-1.21) and school-age asthma (pOR, 1.13; 95% CI, 1.01-1.27). CONCLUSION Younger gestational age at birth and higher infant weight gain were associated with childhood asthma outcomes. The associations of lower birth weight with childhood asthma were largely explained by gestational age at birth.

Social Factors Associated with Readiness for Sexual Activity in Adolescents: A Population-Based Cohort Study

Various factors are associated with sexual activity in adolescence and it is important to identify those that promote healthy and adaptive romantic and sexual development. The objectives of this study were to describe rates of early sexual intercourse (before 16 years) and sexual readiness in adolescence and to assess the extent to which these were social patterned. We prospectively studied nearly 5,000 15-year-olds from the Avon Longitudinal Study of Parents and Children, a UK birth cohort. Between 2006 and 2008, female and male participants answered a computer assisted interview about romantic and sexual behaviors in the last year. Predictors of sexual intercourse and readiness for sexual intercourse were examined across a range of sociodemographic measures. Overall, 17.7 % (95 % CI 16.7 %, 18.9 %) of participants reported having had sexual intercourse in the last year, with more girls than boys reporting sexual experience (risk ratio 1.30, 95 % CI 1.15, 1.47). Of these, one-third of both male and female were classed as unready because they were unwilling, lacking in autonomy, felt regret or had not used contraception. There was strong evidence of social patterning for sexual activity with higher rates for young people from poorer homes, with lower social class, and with younger, less educated mothers. In contrast, among 860 young people who had had sexual intercourse, there was no clear evidence of associations between social factors and sexual readiness. The lack of social patterning in sexual readiness supports the provision of comprehensive education to develop life skills for adolescents across all social groups.

Rhinovirus Infections and Associated Respiratory Morbidity in Infants: A Prospective Cohort Study.

BACKGROUND Risk factors promoting rhinovirus (RV) infections are inadequately described in healthy populations, especially infants. OBJECTIVES To determine the frequency of symptomatic and asymptomatic RV infections and identify possible risk factors from host and environment among otherwise healthy infants. METHODS In a prospective birth cohort, respiratory health was assessed in 41 term-born infants by weekly telephone interviews during the first year of life, and weekly nasal swabs were collected to determine RV prevalence. In a multilevel logistic regression model, associations between prevalence and respiratory symptoms during RV infections and host/environmental factors were determined. RESULTS 27% of nasal swabs in 41 infants tested positive for RVs. Risk factors for RV prevalence were autumn months (OR=1.71, p=0.01, 95% CI 1.13-2.61), outdoor temperatures between 5-10 °C (OR=2.33, p=0.001, 95% CI 1.41-3.86), older siblings (OR=2.60, p=0.001, 95% CI 1.50-4.51) and childcare attendance (OR=1.53, p=0.07, 95% CI 0.96-2.44). 51% of RV-positive samples were asymptomatic. Respiratory symptoms during RV infections were less likely during the first three months of life (OR=0.34, p=0.003, 95% CI 0.17-0.69) and in infants with atopic mothers (OR=0.44, p=0.008, 95% CI 0.24-0.80). Increased tidal volume (OR=1.67, p=0.03, 95% CI 1.04-2.68) and outdoor temperatures between 2-5 °C (OR=2.79, p=0.02, 95% CI 1.17-6.61) were associated with more symptoms. CONCLUSIONS RVs are highly prevalent during the first year of life, and most infections are asymptomatic. Frequency of RV infections is associated with environmental factors, while respiratory symptoms during RV infections are linked to host determinants like infant age, maternal atopy, or premorbid lung function.

Breastfeeding and obesity at 14 years: A cohort study

Aim: To determine the influence of breastfeeding on overweight and obesity in early adolescence. Methods: Data about breastfeeding duration, BMI of children at 14 years, and confounding variables, were collected from an ongoing longitudinal study of a birth cohort of 7776 children in Brisbane. Prevalence of overweight and obesity at 14 years was assessed according to duration of breastfeeding, with logistic regression being used to adjust for the influence of confounders. Results: Data were available for 3698 children, and those not included were significantly different in age, educational level, income, race, birthweight, and small-for-gestational-age status. Breastfeeding for longer than six months was protective of obesity (OR 0.6, 95% CI 0.4, 0.96) though not of overweight. When confounding variables were considered the effect size diminished and lost statistical significance OR 0.8 (95% CI 0.5, 1.3). Breastfeeding for less than 6 months had no effect on either obesity or overweight though a trend was found for increased prevalence of overweight at 14 years with shorter periods of breastfeeding. Conclusion: This investigation contributes to the gathering body of evidence that breastfeeding for longer than 6 months has a modest protective effect against obesity in adolescence.

Brain hyperintensity location determines outcome in the triad of impaired cognition, physical health and depressive symptoms : A cohort study in late life

The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36). Image acquisition and image analysis for ABC36 were funded by the Alzheimer’s Research Trust (now Alzheimer’s Research UK). A.D.M., C.J.M., S.S., L.J.W., and R.T.S. have received grants from: Chief Scientist Office, Department of Health, Scottish Government; Biotechnology and Biological Sciences Research Council

Brain hyperintensity location determines outcome in the triad of impaired cognition, physical health and depressive symptoms : A cohort study in late life

The authors would like to thank the participants of the Aberdeen 1936 Birth Cohort (ABC36). Image acquisition and image analysis for ABC36 were funded by the Alzheimer’s Research Trust (now Alzheimer’s Research UK). A.D.M., C.J.M., S.S., L.J.W., and R.T.S. have received grants from: Chief Scientist Office, Department of Health, Scottish Government; Biotechnology and Biological Sciences Research Council

Prevalence and risk factors for mild and high-frequency bilateral sensorineural hearing loss at age 11 years old:a UK prospective cohort study

OBJECTIVE: This study aimed to assess prevalence and risk factors for mild/high-frequency bilateral sensorineural hearing loss within a UK population of children at age 11 years. DESIGN: Prospective birth cohort study. STUDY SAMPLE: Repeat hearing thresholds were measured in 5032 children, as part of the Avon Longitudinal Study of Parents and Children (ALSPAC) at age 7, 9, and 11 years. Pregnancy, birth, and early medical history were obtained prospectively through parental questionnaires and medical records. RESULTS: Twenty children had mild and seven had high-frequency bilateral sensorineural hearing loss, giving a combined prevalence of 0.5% (95% CI 0.4-0.8%). These children were more likely than the rest of the study sample to have been admitted to hospital at 6-18 months (OR 2.7, 95% CI 1.00-7.30). Parents of these children were more likely to have suspected a hearing problem when the children were 3 years old (OR 2.4, 95% CI 1.05-5.60). CONCLUSIONS: This is the first UK prospective cohort study to investigate the prevalence of mild and high-frequency hearing loss. This study, which has the advantage of a large sample size and repeat hearing measures over a four year period, reports lower prevalence values than US cross-sectional studies.

Avaliação das declarações de nascido vivo como fonte de informação sobre defeitos congênitos

OBJETIVO: Estimar a prevalência de defeitos congênitos (DC) em uma coorte de nascidos vivos (NV) vinculando-se os bancos de dados do Sistema de Informação de Mortalidade (SIM) e do Sistema de Informação sobre Nascidos Vivos (SINASC). MÉTODOS: Estudo descritivo para avaliar as declarações de nascido vivo como fonte de informação sobre DC. A população de estudo é uma coorte de NV hospitalares do 1º semestre de 2006 de mães residentes e ocorridos no Município de São Paulo no período de 01/01/2006 a 30/06/2006, obtida por meio da vinculação dos bancos de dados das declarações de nascido vivo e óbitos neonatais provenientes da coorte. RESULTADOS: Os DC mais prevalentes segundo o SINASC foram: malformações congênitas (MC) e deformidades do aparelho osteomuscular (44,7%), MC do sistema nervoso (10,0%) e anomalias cromossômicas (8,6%). Após a vinculação, houve uma recuperação de 80,0% de indivíduos portadores de DC do aparelho circulatório, 73,3% de DC do aparelho respiratório e 62,5% de DC do aparelho digestivo. O SINASC fez 55,2% das notificações de DC e o SIM notificou 44,8%, mostrando-se importante para a recuperação de informações de DC. Segundo o SINASC, a taxa de prevalência de DC na coorte foi de 75,4%00 NV; com os dados vinculados com o SIM, essa taxa passou para 86,2%00 NV. CONCLUSÕES: A complementação de dados obtida pela vinculação SIM/SINASC fornece um perfil mais real da prevalência de DC do que aquele registrado pelo SINASC, que identifica os DC mais visíveis, enquanto o SIM identifica os mais letais, mostrando a importância do uso conjunto das duas fontes de dados.

Economic impact of a rotavirus vaccine in Brazil

The study was done to evaluate the cost-effectiveness of a national rotavirus vaccination programme in Brazilian children from the healthcare system perspective. A hypothetical annual birth-cohort was followed for a five-year period. Published and national administrative data were incorporated into a model to quantify the consequences of vaccination versus no vaccination. Main outcome measures included the reduction in disease burden, lives saved, and disability-adjusted life-years (DALYs) averted. A rotavirus vaccination programme in Brazil would prevent an estimated 1,804 deaths associated with gastroenteritis due to rotavirus, 91,127 hospitalizations, and 550,198 outpatient visits. Vaccination is likely to reduce 76% of the overall healthcare burden of rotavirus-associated gastroenteritis in Brazil. At a vaccine price of US$ 7-8 per dose, the cost-effectiveness ratio would be US$ 643 per DALY averted. Rotavirus vaccination can reduce the burden of gastroenteritis due to rotavirus at a reasonable cost-effectiveness ratio.

Serious criminal offending and mental disorder - Case linkage study

Background A relationship exists between mental disorder and offending behaviours but the nature and extent of the association remains in doubt. Method Those convicted in the higher courts of Victoria between 1993 and 1995 had their pyschiatric history explored by case linkage to a register listing virtually all contacts with the public psychiatric services. Results Prior psychiatric contact was found in 25% or offenders, but the personality disorder and substance misuse accounted for much of this relationship. Schizophrenia and affective disorders were also over-represented, particularly those with coexisting substance misuse. Conclusions The increased offending in schizophrenia and affective illness is modest and may often be mediated by coexisting substance misuse. The risk of a serious crime being committed by someone with a major mental illness is small and does not justify subjecting them, as a group, to either increased institutional containment or greater coercion.