Prevention of asthma in genetically susceptible children: a multifaceted intervention trial focussed on feasibility in general practice

Abstract

Background: Although the effectiveness of the multifaceted allergen-reducing interventions for the prevention of asthma in susceptible children was showed to be proven, the feasibility was not clear.

Methods: The research question of the PREVention of asthma in susceptible children (PREVASC) trial was focused on the assessment of the effectiveness and feasibility of a multifaceted intervention on the prevention of allergic asthma in general practice. The effectiveness and feasibility of an intervention aimed at the simultaneous reduction in the environmental exposures to inhalant- and food allergens in susceptible children was investigated. A total of 476 children susceptible for developing asthma were initially included during pregnancy and were randomly divided over an intervention group of n = 222 children whose parents were offered a multifaceted environmental exposure-reducing intervention. Controls (n = 221) received usual care. The main outcome was 'diagnosis of allergic asthma at age 6'.

Results: A significant reduction in inhalant allergen exposure levels of house dust mite [(Der p1), p = 0.043], cat [(Fel d1), p = 0.037], and dog [(Can f1), p = 0.012] was reached. Significantly more intervention group children started using cow's milk and solids after the age of 6 months (p ≤ 0.001). No statistical difference, however, was reached between groups on the duration of breast-feeding (p = 0.635) and the reduction in smoke exposure (p = 0829). At age 6, the intervention had no influence on the development of main outcome allergic asthma (OR = 1.010 (CI 0.580-1.758).

Conclusion: Other primary preventive asthma-reducing interventions were shown to be effective in reducing the occurrence of asthma for at least the first 7-8 yr of life. The multifaceted PREVASC allergic asthma primary preventive intervention was effective in reducing the exposure to inhalant and food allergens, but was not feasible for the parents. A lack of sufficient room for improvement focus on stimulating adherence seemed to be involved. It is suggested that a multifaceted environmental exposure-reducing intervention may have to be adapted to the personal circumstances of patients at baseline.