The odds ratio is a useful estimate of the relative riskwhen:
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The disease is rare/infrequent |
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The exposure is common |
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The number of controls is equal to the number of cases |
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The association is truly causal |
In a case-control study of teenage suicide, interviews wereconducted with the parents of 100 teenagers who had committedsuicide and the parents of 100 teenagers who had died from othercauses. Of the teenagers who committed suicide, 40 of themexperienced substance abuse problems per their parents. Of theteenagers who died from other causes, 10 of them experiencedsubstance abuse problems per their parents. The incidence ofsuicide among teenagers with substance abuse problems in thegeneral population is:
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50% |
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40% |
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10% |
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Incidence in the general population cannot be determined fromthis study design |
