Compliance of asthmatic families with a primary prevention programme of asthma and effectiveness of measures to reduce inhalant allergens--a randomized trial.

BACKGROUND Compliance to and the effect of pre- and post-natal exposure reduction measures to prevent asthma in high-risk children from asthmatic families were studied. METHOD Families were randomized to a special care group (n=222) and a control group (n=221). Educational advice on measures to reduce their newborn's exposure to allergens and smoke was provided to the special care group during three visits (two pre-natal and one post-natal). The control group (n=221) received usual care. RESULT After the intervention, the special care group differed significantly (P<0.01) from the usual care group in: use of anti-mite encasings (parental: 88% vs. 14%; baby: 98% vs. 10%); keeping pets outside (51% vs. 19%); combined breast- and hypoallergenic formula feeding (55% vs. 22%); first solids postponement until after the sixth month (71% vs. 28%); maternal post-natal smoking (52% vs. 28%). Little or no compliance was found for other sanitary measures (cleaning habits, providing a smooth floor covering, ventilation/airing, pet removal), exclusive breastfeeding, pre-natal smoking and partner smoking. In spite of pre-existent low allergen levels in both groups, there was a significant reduction of mite, cat, and dog allergens on the mattresses and mite and cat allergens in the living room in the special care group and were significantly lower compared with the usual care group after 1 year. CONCLUSION High compliance was found for the use of anti-mite encasings; substantial compliance for using hypoallergenic formula, solid food postponement, keeping pets outside and reported post-natal maternal smoking. There was no compliance for sanitary measures and the reduction of maternal pre-natal passive smoking. Mite and pet allergens on mattresses were strongly reduced by anti-mite encasings.