PREVASC-OMEGA; Prevention of asthma in children at high risk of developing asthma.

In the scope of the PREVASC-study on the PREVention of Asthma in Children, 443 familial predisposed children are being followed from the prenatal period until the age of two years (PREVASC-study, NAF project 96-34, KNAW-fellowship 1997-1999, Prevention Fund project 26-146). These children were randomly allocated to an intervention group or an usual care group. The intervention consisted of advice on measures to decrease the exposure of the child to allergens (house dust mite HDM, cat and dog allergens) and cigarette smoke. Next to these advices, the mothers were stimulated to completely breast feed their child from birth until the age of 6 months and not to start feeding them solid foods until the age of 6 months. For reducing the HDM allergen exposure the children received HDM impermeable mattress covers.
The control group received usual care.
At the time the children have reached the age of two, all parents were approached to continue their participation in the study (OMEGA-study, NAF project 3.2.99.38). After their informed consent was received, the children in the original intervention group were equally divided over two separate intervention groups after randomization. One of the intervention groups was no longer exposed to advice and HDM impermeable mattress covers (short intervention period: 0-2 years; a minimum of 97 children required). The other intervention group continued to be advised about the diminishing of allergen and smoke exposure and was advised to keep on using HDM impermeable mattress covers (extended intervention period: 0-6 years; a minimum of 97 children required). The children that participated in the original control group form the control group of the second part of the study as well and receive usual care (a minimum of 194 children required).

Just like the first part of the study (PREVASC) allergen and cigarette smoke exposure and health problems possibly related to allergic disease and asthma are monitored in all three groups in the exact same manner. At six years of age (of the child) all parents will receive an invitation to take their child to the hospital to perform lung function tests. The outcome of these lung function tests together with the longitudinally collected data on respiratory morbidity will be used to determine if a child can be labeled as having asthma or not.

Children in the intervention group will show to have less asthma symptoms and a better lung function than children in the control group as measured at age 6 years by questionnaire (symptoms), General practitioners registration (symptoms), and lung function measurements (microRint, FEHO, FEV1, PC20, reversibility).

N/A

Advisory intervention on reducing exposure to:
Allergen exposure (house dust mite, cat and dog allergens);

Food allergens by exclusively breastfeeding for a period of 6 months or if not possible feeding the child with hypo-allergenic formula, introducing solids until 6 months;

Environmental tobacco smoke (parents stop smoking).

Control group: usual care.