Is parent–child bed-sharing a risk for wheezing and asthma in early childhood?

Abstract

Household crowding can place young children at risk for respiratory infections which subsequently provoke asthma symptoms. However, crowding might also protect against asthma, in accordance with the hygiene hypothesis. We tested if parent-infant bed-sharing, an important dimension of household crowding, increases or decreases the risk for asthma.In a population-based prospective cohort (N = 6160) we assessed bed-sharing at 2 and 24 months; wheezing between 1 and 6 years of age; and asthma at 6 years of age. Generalised estimating equation models were used to assess repeated measures of wheezing and asthma.We found no association between bed-sharing in early infancy and wheezing or diagnosis of asthma. By contrast, we found a positive association between bed-sharing in toddlerhood and both wheezing (OR 1.42, 95% CI 1.15-1.74) and asthma (OR 1.57, 95% CI 1.03-2.38). Wheezing was not associated with bedsharing when using cross-lagged modelling.This study suggests that bed-sharing in toddlerhood is associated with an increased risk of asthma at later ages, and not vice versa. Further studies are needed to explore the underlying causal mechanisms. @ERSpublications More wheezing and asthma reported for bed-sharing toddlers, not for infants: parental vigilance or increased risk?

Bed-sharing and childhood asthma: from associations to causal modelling

“…The effects of single risk factors are often small and the direction of causal pathways questionable, such as in the study by LUIJK et al [1]. Standard statistical methods are largely not adapted to detect them and this may be the cause of many contradicting results in the clinical literature [8].…”

“…If anything, the studies missed because their abstracts did not describe their methodology will have used less, rather than more, novel causal methods. In summary, our two searches therefore suggest that causal models, such as used by LUIJK et al [1], represent a rare exception in epidemiological articles in ERS publications.…”

“…We need to explore causal associations and apply novel statistical approaches in respiratory epidemiology http://ow.ly/GWOYT The paper by LUIJK et al [1] in this issue of the European Respiratory Journal is a highlight for two reasons: it is the first to investigate parent-child bed-sharing practices and risk of childhood asthma; and it uses novel statistical approaches to explore causal relationships.…”

“…We wanted to know how representative the methods used by LUIJK et al [1] are of current epidemiological studies investigating causal relationships. To this end, we undertook a quick systematic review of all papers published by the four regular European Respiratory Society (ERS) publications (European Respiratory Journal, European Respiratory Review, ERS Monograph and Breathe) since 1988.…”

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@ERSpublicationsWe need to explore causal associations and apply novel statistical approaches in respiratory epidemiology http://ow.ly/GWOYT The paper by LUIJK et al [1] in this issue of the European Respiratory Journal is a highlight for two reasons: it is the first to investigate parent-child bed-sharing practices and risk of childhood asthma; and it uses novel statistical approaches to explore causal relationships.One can hypothesise diverse influences of bed-sharing practices on respiratory disease. First, the close contact between bed-sharing parents and their offspring could lead to increased transmission of infectious agents and, thus, more virus-induced wheeze in the children.

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