Wheezing at 8 and 13 years: Changing importance of bronchiolitis and passive smoking

Authors

  • Dr. Kenneth M. McConnochie MD,

    Corresponding author
    1. Department of Pediatrics, Rochester General Hospital, Rochester, New York
    • Department of Pediatrics, Rochester General Hospital, 1425 Portland Avenue, Rochester, NY 14621
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  • Klaus J. Roghmann PhD

    1. Department of Pediatrics, University of Rochester School of Medicine, Rochester, New York
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  • This study was supported in part by the Robert Wood Johnson Foundation (General Pediatrics Academic Development Program Grant No. 4961) and by the Rochester General Hospital Medical Advisory Committee Research Fund.

  • This work was made possible by the foresight, initiative, and cooperation of Suzanne W. Klein, MD; Thomas K. McInerny, MD; James B. MacWhinney, MD: Robert L. Miller, MD; and Lawrence F Nazarian, MD of the Panorama Pediatric Group and the Department of Pediatrics, University of Rochester School of Medicine. The authors also gratefully acknowledge the assistance of Judith Neuderfer, RN, in conducting interviews.

Abstract

A group of 153 children (51 with a history of bronchiolitis and 102 matched controls) were evaluated in a historical cohort study at a mean age of 8 years and again at 13 years to test the primary hypothesis that mild bronchiolitis, far more common than severe (hospitalized) bronchiolitis, predicts wheezing. A secondary hypothesis was that passive smoking also predicts wheezing. Many potentially confounding variables such as family history of asthma were controlled in analyses.

Analysis at 13 years produced results that were not anticipated from previous analysis of interviews at age 8. Although mild bronchiolitis was a powerful predictor of wheezing at age 8 years, it was no longer a strong predictor of wheezing at age 13 in either bivariate or multivariate analysis. Although epidemiologic studies, by their nature, cannot prove causality, findings are consistent with the hypothesis that sequelae often follow mild bronchiolitis but diminish during childhood.

Maternal smoking was a powerful predictor of wheezing at age 13 in bivariate analysis (Kendall's Tau B = 0.19, P < 0.01) and in multivariate analysis (odds ratio = 2.67, P < 0.01). In children at highest risk for wheezing, males with a family history of asthma, multivariate analysis suggested that maternal smoking is associated with an increase in wheezing from 36% to 60%. We conclude that passive smoking, previously identified as a risk factor in this population for both bronchiolitis in infancy and wheezing at age 8, is a risk factor for wheezing-associated morbidity throughout the childhood years.

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