A Systematic Review and Meta-Analysis of Interventions Used to Reduce Exposure to House Dust and Their Effect on the Development and Severity of Asthma

Abstract

ObjectivesWe assessed whether any household dust reduction intervention has the effect of increasing or decreasing the development or severity of atopic disease.Data sourcesElectronic searches on household intervention and atopic disease were conducted in January 2007 in EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials. No date or language restriction was placed on the literature search.Data extractionWe included randomized controlled trials comparing asthma outcomes in a household intervention group with either placebo intervention or no intervention.Data sysnthesisFourteen studies met the inclusion criteria. Eight recruited antenatally and measured development of atopic disease. Six recruited known atopic individuals and measured disease status change. Meta-analyses on the prevention studies found that the interventions made no difference to the onset of wheeze but made a significant reduction in physician-diagnosed asthma. Meta-analysis of lung function outcomes indicated no improvement due to the interventions but found a reduction in symptom days. Qualitatively, health care was used less in those receiving interventions. However, in one study that compared intervention, placebo, and control arms, the reduction in heath care use was similar in the placebo and intervention arms.ConclusionsThis review suggests that there is not sufficient evidence to suggest implementing hygiene measures in an attempt to improve outcomes in existing atopic disease, but interventions from birth in those at high risk of atopy are useful in preventing diagnosed asthma but not parental-reported wheeze.

A reintroduction of environmental mite allergen control strategies for asthma treatment and the debate on their effectiveness

“…The HEPA filters were studied in varying environmental settings. Macdonald et al studied the effectiveness of textile‐based strategies for the primary and tertiary prevention of asthma. They reported on the number of days ill due to asthma and a lung function parameter combining the FEV 1 with the peak flow .…”

“…Macdonald et al studied the effectiveness of textile‐based strategies for the primary and tertiary prevention of asthma. They reported on the number of days ill due to asthma and a lung function parameter combining the FEV 1 with the peak flow . Campbell and Gibson attempted to study the effects of feather bedding, but the selected trials did not meet the inclusion criteria.…”

“…Huiyan et al investigated six trials on mite‐impermeable covers combined with one trial on humidity control. Three of the trials investigated by Huiyan et al were also included in the analysis by Gøtzsche and Johansen . To some extent, many meta‐analyses can be considered to represent subsets of the large meta‐analysis by Gøtzsche and Johansen …”

Perinatal and early childhood environmental factors influencing allergic asthma immunopathogenesis

“…Recent meta-analyses have shown multifaceted allergen remediation programs to be protective 181, 182 against the development of asthma with 20-50% reduction in odds 172, 173 , though other studies have been disappointing 77, 183 . The most protective effect was seen in children with greater than 5 years of follow-up 182 , indicating a true decrease in risk to those prone to develop atopic asthma.…”

“…The most protective effect was seen in children with greater than 5 years of follow-up 182 , indicating a true decrease in risk to those prone to develop atopic asthma. Macdonald, et al 181 found that the decrease in physician diagnosed asthma did not carry over to the outcome of parental report of wheeze raising the question of whether there was mitigation of severity rather than prevention of disease. Those without physician diagnosis may not have presented with such significant symptoms to warrant asthma diagnosis.…”