Asthma and wheezing disorders are common chronic health problems in childhood. Breastfeeding provides health benefits, but it is not known whether or how breastfeeding decreases the risk of developing asthma. We performed a systematic review and meta-analysis of studies published between 1983 and 2012 on breastfeeding and asthma in children from the general population. We searched the PubMed and Embase databases for cohort, cross-sectional, and case-control studies. We grouped the outcomes into asthma ever, recent asthma, or recent wheezing illness (recent asthma or recent wheeze). Using random-effects meta-analyses, we estimated pooled odds ratios of the association of breastfeeding with the risk for each of these outcomes. We performed meta-regression and stratified meta-analyses. We included 117 of 1,464 titles identified by our search. The pooled odds ratios were 0.78 (95% confidence interval: 0.74, 0.84) for 75 studies analyzing "asthma ever," 0.76 (95% confidence interval: 0.67, 0.86) for 46 studies analyzing "recent asthma," and 0.81 (95% confidence interval: 0.76, 0.87) for 94 studies analyzing recent wheezing illness. After stratification by age, the strong protective association found at ages 0-2 years diminished over time. We found no evidence for differences by study design or study quality or between studies in Western and non-Western countries. A positive association of breastfeeding with reduced asthma/wheezing is supported by the combined evidence of existing studies.

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A paediatric interactive therapy system for arm and hand rehabilitation Abstract-Paediatric rehabilitation using virtual reality systems pose unique usability challenges distinct from those in adult rehabilitation. These challenges relate to the different epidemiology and aetiology of children's disorders requiring rehabilitation and the physical design of interactive virtual reality hardware for children of varying sizes. Just as importantly, children need highly entertaining interactive scenarios that suit their differing levels of cognitive development and thus their differing abilities to comprehend gaming scenarios. In this paper we present our virtual realitybased Paediatric Interactive Therapy System (PITS) designed specifically for upper arm rehabilitation in children aged from five years of age upwards. It incorporates a range of interchangeable position sensing devices (compass, bend sensor, pressure sensor and camera tracking) that can be adjusted to a large range of different hand sizes, and interactive gaming scenarios specifically designed for maximum entertainment value for children. We describe the neuroscientific principles behind our system, the technical details of the hardware components and the design of the interactive scenarios. An initial usability and patient acceptance pilot study has been conducted at the Rehabilitation Centre Affoltern of the University Children's Hospital Zurich. To date all patients have accepted the system, and trained in reaching and grasping tasks at a far higher rate than in conventional occupational therapy. The system thus promises to be a valuable complement to conventional therapeutic programs offered in rehabilitation clinics.

Knowledge of these age-related changes in wheezing illness is informative for health care planning and the design of future research projects and questionnaires.

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BackgroundEstimates of prevalence of wheeze depend on questionnaires. However, wording of questions may vary between studies. We investigated effects of alternative wording on estimates of prevalence and severity of wheeze, and associations with risk factors.MethodsWhite and South Asian children from a population-based cohort (UK) were randomly assigned to two groups and followed up at one, four and six years (1998, 2001, 2003). Parents were asked either if their child ever had “attacks of wheeze” (attack group, N=535), or “wheezing or whistling in the chest” (whistling group, N=2859). All other study aspects were identical, including questions about other respiratory symptoms.ResultsPrevalence of wheeze ever was lower in the attack group than in the whistling group for all surveys (32 vs. 40% in white children aged one year, p<0.001). Prevalence of other respiratory symptoms did not differ between groups. Wheeze tended to be more severe in the attack group. The strength of association with risk factors was comparable in the two groups.ConclusionsThe wording of questions on wheeze can affect estimates of prevalence, but has less impact on measured associations with risk factors. Question wording is a potential source of between-study-heterogeneity in meta-analyses.

We thank Michael Kramer for his insightful comments (1) on our systematic review and meta-analysis on breastfeeding and childhood asthma (2). Following a concise summary of our findings, he points out the high heterogeneity of the results and addresses issues that might explain this, namely the phenotypic variability of asthma, lack of objective measurements, variable degrees of measurement bias, and residual confounding.We entirely agree with Professor Kramer that "asthma" is a label applied to a heterogeneous syndrome, consisting of several distinct phenotypes, each with its own pathophysiological mechanisms and risk factors (3,4). Transient wheeze induced by viral infections in an infant is likely a different entity than chronic, multitrigger asthma in an atopic schoolchild. Not accounting for this phenotypic variability might explain part of the heterogeneity we found, but not all. Arguably, breastfeeding can act as protective mechanism for either phenotype through different mechanisms influencing respiratory infections and/or priming the immune system. We think that a big part of the heterogeneity is due to poor or incomplete operational definitions of asthma by the studies analyzed. The definitions of the outcome varied greatly, from "wheezing in the past 12 months" through "Does your child have asthma?" and to more elaborated constructions such as "3 reported episodes of wheeze during first 2 years of life treated with inhaled steroids or signs of hyperactivity without upper respiratory infection." These definitions describe different outcomes in terms of phenotype and severity and are sometimes incomplete or have insufficient validity. It is essential that asthma studies define and measure more clearly the particular phenotype(s) they are studying by including more standardized asthma-specific survey questions and, whenever possible, objective measurements such as different tests of lung function, bronchial responsiveness, and airway inflammation. Equally important, studies should report more clearly the age at first diagnosis and the history of the condition; these things were rather fuzzy in the studies we analyzed.For a true assessment of a dose-response relationship, breastfeeding should ideally be recorded as duration in months or-less preferred-by using several categories. Only 4 studies used a continuous variable, whereas a third compared breastfeeding "ever" with "never." The rest used variables with 3-6 categories, which were incompatible across many studies. This made it difficult to investigate dose-response relationships in a consistent way, so we decided on a pragmatic approach and dichotomized breastfeeding duration into more versus less. It might be possible to attempt a follow-up study on a smaller sample of suitable studies and perform a dose-response meta-analysis. It is imperative that studies of breastfeeding record it as a continuous measure. It does not require additional measurement, and maternal recall is reliable (5,6).A measurement bias due to nonblinding of the observers is also...