Risk factors for non-atopic asthma/wheeze in children and adolescents: a systematic review.

BACKGROUND: The study of non-atopic asthma/wheeze in children separately from atopic asthma is relatively recent. Studies have focused on single risk factors and had inconsistent findings. OBJECTIVE: To review evidence on factors associated with non-atopic asthma/wheeze in children and adolescents. METHODS: A review of studies of risk factors for non-atopic asthma/wheeze which had a non-asthmatic comparison group, and assessed atopy by skin-prick test or allergen-specific IgE. RESULTS: Studies of non-atopic asthma/wheeze used a wide diversity of definitions of asthma/wheeze, comparison groups and methods to assess atopy. Among 30 risk factors evaluated in the 43 studies only 3 (family history of asthma/rhinitis/eczema, dampness/mold in the household, and lower respiratory tract infections in childhood) showed consistent associations with non-atopic asthma/wheeze. No or limited period of breastfeeding was less consistently associated with non-atopic asthma/wheeze. The few studies examining the effects of overweight/obesity and psychological/social factors showed consistent associations. We used a novel graphical presentation of different risk factors for non-atopic asthma/wheeze, allowing a more complete perception of the complex pattern of effects. CONCLUSIONS: More research using standardized methodology is needed on the causes of non-atopic asthma

A joint model for vehicle type and fuel type choice: evidence from a cross-nested logit study

In the face of growing concerns about greenhouse gas emissions, there is increasing interest in forecasting the likely demand for alternative fuel vehicles. This paper presents an analysis carried out on stated preference survey data on California consumer responses to a joint vehicle type choice and fuel type choice experiment. Our study recognises the fact that this choice process potentially involves high correlations that an analyst may not be able to adequately represent in the modelled utility components. We further hypothesise that a cross-nested logit structure can capture more of the correlation patterns than the standard nested logit model structure in such a multi-dimensional choice process. Our empirical analysis and a brief forecasting exercise produce evidence to support these assertions. The implications of these findings extend beyond the context of the demand for alternative fuel vehicles to the analysis of multi-dimensional choice processes in general. Finally, an extension verifies that further gains can be made by using mixed GEV structures, allowing for random heterogeneity in addition to the flexible correlation structures

Maternal Depressive Symptoms across Early Childhood and Asthma in School Children: Findings from a Longitudinal Australian Population Based Study

There is a growing body of evidence attesting to links between early life exposure to stress and childhood asthma. However, available evidence is largely based on small, genetically high risk samples. The aim of this study was to explore the associations between the course of maternal depressive symptoms across early childhood and childhood asthma in a nationally representative longitudinal cohort study of Australian children. Participants were 4164 children and their biological mothers from the Longitudinal Study of Australian Children. Latent class analysis identified three trajectories of maternal depressive symptoms across four biennial waves from the first postnatal year to when children were 6-7 years: minimal symptoms (74.6%), sub-clinical symptoms (20.8%), and persistent and increasing high symptoms (4.6%). Logistic regression analyses revealed that childhood asthma at age 6-7 years was associated with persistent and increasing high depressive symptoms after accounting for known risk factors including smoking during pregnancy and maternal history of asthma (adjusted OR 2.36, 95% CI 1.61-3.45), p.001). Our findings from a nationally representative sample of Australian children provide empirical support for a relationship between maternal depressive symptoms across the early childhood period and childhood asthma. The burden of disease from childhood asthma may be reduced by strengthening efforts to promote maternal mental health in the early years of parenting

The Prevalence of Attention Deficient Hyperactivity Disorder Among Iranian Children: A Meta-Analysis

Context: Attention deficient hyperactivity disorder (ADHD), diagnosed in psychiatric outpatient clinics, is the most common psychiatric disorder among schoolchildren. The purpose of this study is to conduct a meta-analysis on subscales related to ADHD examined on schoolchildren. Moreover, it is tried to evaluate meta-analysis of ADHD and its subscales in primary school students in Iran. Evidence Acquisition: Searching through the databases of Magiran, SID, Google Scholar, etc. a total of 16 articles were collected and weighted based on the number of cases and prevalence in binomial distribution. By using a random effects model meta-analysis (I2 = 96.5), data were analyzed by the use of R and STATA software (version 11.2). Results: In this analysis, 27 articles published between the years of 2001 and 2016 were used. The total sample size was 15124 students whose ages ranged from six to 14 years old. The prevalence of ADHD based on parents and teachers' consensus was 12 (CI 95: 9.0 -15), from parents' perspective 15.6 (CI 95: 9.8 -21.5), and from teachers' perspective 17.2 (CI 95: 12.7 -21.8). The subgroups' prevalence rates based on parents and teachers' consensus were as follows: Attention deficit (AD) = 4.2, hyperactive impulsive (HI) = 4.1, and combined type (CT) = 3.5. ADHD was more prevalent in boys than girls (7.9 versus 5.5). Conclusions: The results indicated that the prevalence of ADHD among schoolchildren is moderate; therefore, considering the importance of students' mental health, the needs for identification, prevention, and treatment of high-risk groups by responsible institutions become obvious