Passive smoking and croup.

The relationship between croup and the presence of household cigarette consumption was assessed in a matched-pair case control study. Fifty subjects with a primary hospital discharge diagnosis of croup were paired with children with a primary hospital discharge diagnosis of abdominal hernia. The results yielded an estimated relative risk of 0.82. The power of this study to detect a relative risk of 2.0 was 38%. This study fails to show a relationship between passive smoking and croup in early childhood.