Index
When a sign/test/symptom has a high Sensitivity, a Negative result rules out the diagnosis. For example,
the sensitivity of a history of ankle swelling for diagnosing ascites is 93%; therefore is a person
does not have a history of ankle swelling, it is highly unlikely that the person has ascites.
Proportion of people without the target disorder who have a negative test. It is used to assist in
assessing and selecting a diagnostic test/sign/symptom.
What a sign/test/symptom has a high Specificity, a Positive result rules in the diagnosis. For
example, the specificity of a fluid wave for diagnosing ascites is 92%; therefore if a person does
have a fluid wave, it rules in the diagnosis of ascites.
The likelihood that an observed difference between groups within a study represents a real difference
rather than mere chance or the influence of confounding factors, based on both p values and
confidence intervals. Strength of inference is weakened by various forms of bias and by small
sample sizes.
A summary of the medical literature that uses explicit methods to perform a thorough literature
search and critical appraisal of individual studies and that uses appropriate statistical techniques
to combine these valid studies.
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Duke University
Last modified on: 16-Dec-04