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Archived Comments for: Severe respiratory distress in term infants born electively at high altitude

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  1. Odds Ratio (OR) Measure

    MOHAMMED AL-HINDI, University of Calgary

    3 March 2006

    Thank you for this interesting article.

    I just want to make sure about the OR calculation.

    In the abstract and the full text it is mentioned that "Seven of the affected infants were delivered at 37-38 weeks (5.2/1000 births OR = 26, 95%CI -4.6 to 5.8). Five patients delivered at 38 -39 weeks, (2/1000 births) OR = 10 95%CI -4.9 to 5.4)". And then you confirmed that by saying "we found that infants born at 37 and 38 weeks' gestation experience a 26-fold and 10-fold increased risk of severe RDS, respectively". My understanding is that the measure of association, (OR) in this article, should be within the 95% Confidence Interval (CI). The CI of an OR should not be less than zero.

    I did some calculations using statistical program (STATA) OR were 25.2(95%CI 3.2-1136) and 9.7 (95%CI 1.08-459, respectively. These CI are so wide, so I recommend to use the Risk Ratio (RR), since its a prospective cohort study, which will give you the following RR 4 (95%CI 3-5.2) and 2.4 (95%CI 3-5.2), respectively.

    Please let me know your comments.


    Competing interests

    None declared