Question

You conduct a case-control study in Portland pediatric clinics to evaluate the relationship between the exposure of exclusive breastfeeding for at least the first 6 months of life, and the outcome of no ear infections during the first year of life. The exposure is “exclusive breastfeeding” (as opposed to mixed feeding or formula feeding. The outcome of interest is “no ear infections during the first year of life” (as opposed to having at least one ear infection). Your study produces an OR of 0.3, relating exposure and outcome. Assuming that the 95% Confidence Interval indicates your result is statistically significant, the interpretation for the OR in your study is

Question 10 options:

	A) The odds of exclusive breastfeeding among children with no ear infections during the first year of life is 0.3 times that of those with at least one ear infection during the first year of life.
	B) The odds of no ear infections during the first year of life among exclusively breastfed children is 0.3 times the odds in the second year of life.
	C) The odds of exclusive breastfeeding and having no ear infections during the first year of life is 0.3%.
	D) The odds of exclusive breastfeeding and having no ear infections during the first year of life is 0.3 times that of non-exclusive breastfeeding and having at least one ear infection during the first year of life.
	E) None of the above.

Answer 1

Odds Ratio (OR) is a measure of association between exposure and an outcome. The OR represents the odds that an outcome will occur given a particular exposure, compared to the odds of the outcome occurring in the absence of that exposure.

option E) None of the above is correct