Question 8: What is meant by odds ratio 0.52 for runny nose and asthma and what does it tell us?
The odds of asthma is the number with asthma divided by the number without asthma, or the proportion with asthma divided by the proportion without asthma. The odds ratio is the odds of asthma among those with one episode of runny nose divided by the odds of asthma for those with two episodes of runny nose, so the odds of asthma in children with two episodes is half the odds in children with one episode. Asthma is less likely in children with two episodes of runny nose before age one.
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Last updated: 27 July, 2009.