Exploring educational disparities in risk of preterm delivery: a comparative study of 12 European birth cohorts.

BACKGROUND: An association between education and preterm delivery has been observed in populations across Europe, but differences in methodology limit comparability. We performed a direct cross-cohort comparison of educational disparities in preterm delivery based on individual-level birth cohort data. METHODS: The study included data from 12 European cohorts from Denmark, England, France, Lithuania, the Netherlands, Norway, Italy, Portugal, and Spain. The cohorts included between 2434 and 99 655 pregnancies. The association between maternal education and preterm delivery (22-36 completed weeks of gestation) was reported as risk ratios, risk differences, and slope indexes of inequality with 95% confidence intervals (CIs). RESULTS: Singleton preterm live delivery proportion varied between 3.7% and 7.5%. There were large variations between the cohorts in the distribution of education and maternal characteristics. Nevertheless, there were similar educational differences in risk of preterm delivery in 8 of the 12 cohorts with slope index of inequality varying between 2.2 [95% CI 1.1, 3.3] and 4.0 [95% CI 1.4, 6.6] excess preterm deliveries per 100 singleton deliveries among the educationally most disadvantaged, and risk ratio between the lowest and highest education category varying from 1.4 [95% CI 1.1, 1.8] to 1.9 [95% CI 1.2, 3.1]. No associations were found in the last four cohorts. CONCLUSIONS: Educational disparities in preterm delivery were found all over Europe. Despite differences in the distributions of education and preterm delivery, the results were remarkably similar across the cohorts. For those few cohorts that did not follow the pattern, study and country characteristics did not explain the differences.

Evaluation of systematic assessment of asthma-like symptoms and tobacco smoke exposure in early childhood by well-child professionals: a randomised trial.

OBJECTIVES: This study aimed to evaluate the effectiveness of systematic assessment of asthma-like symptoms and environmental tobacco smoke (ETS) exposure during regular preventive well-child visits between age 1 and 4 years by well-child professionals. METHODS: Sixteen well-child centres in Rotterdam, the Netherlands, were randomised into 8 centres where the brief assessment form regarding asthma-like symptoms and ETS exposure was used and 8 centres that applied usual care. 3596 and 4179 children (born between April 2002 and January 2006) and their parents visited the intervention and control centres, respectively. At child's age 6 years, physician-diagnosed asthma ever, wheezing, fractional exhaled nitric oxide (FeNO), airway resistance (Rint), health-related quality of life (HRQOL) and ETS exposure at home ever were measured. Linear mixed models were applied. RESULTS: No differences in asthma, wheezing, FeNO, Rint or HRQOL measurements between intervention and control group were found using multilevel regression in an intention-to-treat analysis (p>0.05). Children of whom the parents were interviewed by using the brief assessment form at the intervention well-child centres had a decreased risk on ETS exposure at home ever, compared to children who visited the control well-child centres, in an explorative per-protocol analysis (aOR = 0.71, 95% CI:0.59-0.87). CONCLUSIONS: Systematic assessment and counselling of asthma-like symptoms and ETS exposure in early childhood by well-child care professionals using a brief assessment form was not effective in reducing the prevalence of physician-diagnosed asthma ever and wheezing, and did not improve FeNO, Rint or HRQOL at age 6 years. Our results hold some promise for interviewing parents and using information leaflets at well-child centres to reduce ETS exposure at home in preschool children. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN15790308.

Predicting asthma in preschool children with asthma-like symptoms: validating and updating the PIAMA risk score.

BACKGROUND: The Prevention and Incidence of Asthma and Mite Allergy (PIAMA) risk score predicts the probability of having asthma at school age among preschool children with suggestive symptoms. OBJECTIVE: We sought to externally validate the PIAMA risk score at different ages and in ethnic and socioeconomic subgroups of children in addition to updating it. METHODS: We studied 2877 children with preschool asthma-like symptoms participating in the multiethnic, prospective, population-based cohort study Generation R. The PIAMA risk score was assessed at preschool age, and asthma was predicted at age 6 years. Discrimination (concordance index [C-index]) and calibration were calculated. The PIAMA risk score was updated, and its performance was similarly analyzed. RESULTS: At age 6 years, 6% (168/2877) of the children had asthma. The discriminative ability of the original PIAMA risk score to predict asthma in Generation R was similar compared with that in the PIAMA cohort (C-index = 0.74 vs 0.71). The predicted risks by using the original PIAMA risk score for having asthma at the age of 6 years tended to be slightly higher than the observed risks (8% vs 6%). No differences in discriminative ability were found at different ages or in ethnic and socioeconomic subgroups (P > .05). The updated PIAMA risk score had a C-index of 0.75. CONCLUSIONS: The PIAMA risk score showed good external validity. The discriminative ability was similar at different ages and in ethnic and socioeconomic subgroups of preschool children, which suggests good generalizability. Further studies are needed to reproduce the predictive performance of the updated PIAMA risk score in other populations and settings and to assess its clinical relevance.

The role of prenatal, perinatal and postnatal factors in the explanation of socioeconomic inequalities in preschool asthma symptoms: the Generation R Study.

BACKGROUND: The authors assessed whether socioeconomic inequalities in asthma symptoms were already present in preschool children and to what extent prenatal, perinatal and postnatal risk factors for asthma symptoms mediate the effect of socioeconomic status (SES). METHODS: The study included 3136 Dutch children participating in the Generation R Study, a prospective cohort study. Adjusted ORs of asthma symptoms for low and middle SES (household income and maternal education) compared to high SES were calculated after adjustment for potential confounders and also adjusted for prenatal, perinatal and postnatal mediators at preschool age. RESULTS: At age 1 year, low-SES children had a 40% lower risk of asthma symptoms compared to high-SES children (p<0.01). However, the risk of asthma symptoms in 3- and 4-year-old low-SES children was 1.5 times higher compared to their high-SES age mates (p<0.05). The positive associations at age 1 year were particularly modified by postnatal factors (up to 38%). In toddlers, prenatal factors explained up to 58% of the negative associations between SES and asthma symptoms. CONCLUSIONS: SES indirectly affects asthma symptoms at preschool age. The inverse association between SES and asthma symptoms emerges at age 3 years. This is particularly due to a high level of adverse prenatal circumstances in low-SES toddlers. Future research should evaluate public health programs (during pregnancy) to reduce socioeconomic inequalities in childhood asthma.