A randomized controlled study on the effectiveness of a multifaceted intervention program in the primary prevention of asthma in high-risk infants

Background: The prevalence of asthma has increased in developed countries i n the past 2 decades. The effectiveness of intervention measures on the pri mary prevention of asthma has not been well studied. Objective: To assess the effectiveness of a multifaceted intervention progr am in the primary prevention of asthma in high-risk infants (in this study, infants are defined as persons from birth to the age of 1 year). Design: Prospective, prenatally randomized, controlled study with follow-up through the age of 1 year. Setting: University hospital-based settings at 2 Canadian centers: Vancouve r, British Columbia, and Winnipeg, Manitoba. Participants: A total of 545 high-risk infants (at least 1 first-degree rel ative with asthma or 2 first-degree relatives with other IgE-mediated aller gic diseases) identified before birth. Interventions: Avoidance of house du st mite and pet allergens and environmental tobacco smoke, encouragement of breastfeeding, and supplementation with a partially hydrolyzed formula. Main Outcome Measures: Probable or possible asthma, rhinitis without appare nt colds, and a prick skin test result positive for common inhalant allerge ns. Results: Thirty-eight (15.1%) of the 251 infants available for assessment i n the intervention group and 49 (20.2%) of the 242 infants available for as sessment in the control group fulfilled the criteria for possible or probab le asthma (adjusted relative risk, 0.66; 90% confidence interval, 0.44-0.98 ). Also, 16.7% of the infants in the intervention group and 27.3% of the in fants in the control group developed rhinitis without colds (adjusted relat ive risk, 0.51; 90% confidence interval, 0.35-0.74). The incidence of posit ive skin test results to 1 or more inhalant allergens was similar in both g roups (4.4% in the intervention group and 4.6% in the control group). Conclusions: Our multifaceted intervention program resulted in a modest but significant (P = .04) reduction in the risk of possible or probable asthma and rhinitis without apparent colds at the age of 12 months in high-risk i nfants. In the absence of a validated definition of asthma at the age of 12 months, follow-up studies are needed to determine the effectiveness of the intervention program in the primary prevention of asthma in high-risk infa nts.