The Journal of Allergy and Clinical Immunology
Volume 116, Issue 1 , Pages 49-55, July 2005

The Canadian Childhood Asthma Primary Prevention Study: Outcomes at 7 years of age

  • Moira Chan-Yeung, MB

      Affiliations

    • From the Occupational and Environmental Lung Disease Unit, Department of Medicine
    • Corresponding Author InformationReprint requests: Moira Chan-Yeung, MB, Respiratory Division, Department of Medicine, 2775, Heather Street, Vancouver, BC, Canada V5Z 3J5.
    • ,
  • Alexander Ferguson, MD

      Affiliations

    • Division of Allergy, Department of Pediatrics, University of British Columbia, Vancouver
    • ,
  • Wade Watson, MD

      Affiliations

    • Section of Allergy and Clinical Immunology, Department of Pediatrics and Child Health, Manitoba Institute of Child Health, University of Manitoba, Winnipeg
    • ,
  • Helen Dimich-Ward, PhD

      Affiliations

    • From the Occupational and Environmental Lung Disease Unit, Department of Medicine
    • ,
  • Roxanne Rousseau, BSc

      Affiliations

    • From the Occupational and Environmental Lung Disease Unit, Department of Medicine
    • ,
  • Marilyn Lilley, RN

      Affiliations

    • Section of Allergy and Clinical Immunology, Department of Pediatrics and Child Health, Manitoba Institute of Child Health, University of Manitoba, Winnipeg
    • ,
  • Anne DyBuncio, BSc

      Affiliations

    • From the Occupational and Environmental Lung Disease Unit, Department of Medicine
    • ,
  • Allan Becker, MD

      Affiliations

    • Section of Allergy and Clinical Immunology, Department of Pediatrics and Child Health, Manitoba Institute of Child Health, University of Manitoba, Winnipeg

Received 18 January 2005; received in revised form 23 March 2005; accepted 24 March 2005. published online 01 June 2005.

Vancouver, British Columbia, and Winnipeg, Manitoba, Canada

Background

Avoidance of any one of the individual risk factors associated with childhood asthma has not been successful in preventing its development.

Objective

The purpose of this study is to determine the effectiveness of a multifaceted intervention program for the primary prevention of asthma in high-risk infants at 7 years of age.

Methods

Five hundred forty-five high-risk infants with an immediate family history of asthma and allergies were prospectively randomized into intervention or control groups prenatally. Intervention measures introduced before birth and during the first year of life included avoidance of house dust, pets, and environmental tobacco smoke and encouragement of breast-feeding with delayed introduction of solid foods. Assessment of outcomes at 7 years consisted of examination by pediatric allergists, methacholine inhalation tests, and allergy skin tests.

Results

At 7 years, 469 of the 545 children were contacted, and 380 returned for further assessment. The prevalence of pediatric allergist–diagnosed asthma was significantly lower in the intervention group than in the control group (14.9% vs 23.0%; adjusted risk ratio, 0.44; 95% CI, 0.25-0.79). The prevalence of allergic rhinitis, atopic dermatitis, atopy (defined as positive skin test reactions to any common allergen), and bronchial hyperresponsiveness (defined as the provocative concentration of methacholine that induced a 20% decrease in FEV1 from a postsaline value of less than 7.8 mg/mL) were not significantly different between the 2 groups. The prevalence of asthma (defined as wheeze without colds and the presence of bronchial hyperresponsiveness) was also significantly lower in the intervention group compared with the control group (12.9% vs 25.0%; adjusted risk ratio, 0.39; 95% CI, 0.22-0.71).

Conclusion

The multifaceted intervention program was effective in reducing the prevalence of asthma in high-risk children at 7 years of age.

Key words: Asthma, primary prevention

Abbreviations used: BHR, Bronchial hyperresponsiveness, OR, Odds ratio, PC20, Provocative concentration of methacholine that induced a 20% decrease in FEV1 from postsaline value, RR, Relative risk

 

 Supported by the Canadian Institute of Health Research, the British Columbia Lung Association, and the Manitoba Medical Service Foundation.Disclosure of potential conflict of interest: A; authors—none disclosed.

PII: S0091-6749(05)00606-8

doi:10.1016/j.jaci.2005.03.029

The Journal of Allergy and Clinical Immunology
Volume 116, Issue 1 , Pages 49-55, July 2005

Article Tools

* Image Usage & Resolution