A study was undertaken to examine the characteristics of a new specific questionnaire for the assessment of quality of life in a diabetic population. One thousand patients were assessed using the reference gold standard. Six hundred and fifty were found to have reduced QoL using the reference and 350 had normal scores and all had the new questionnaire performed too. The investigators report that the sensitivity was 92%, the specificity was 85%, the positive predictive value was 92%, and the negative predictive value 85%. Which value will be affected if the test is applied to a population with a different prevalence of diabetes? a. Likelihood ratio negative b. Likelihood ratio positive c. Positive predictive value correct answer d. Sensitivity e. Specificity Sensitivity and specificity are features of the test that are not influenced by the prevalence of the disease in question, and likelihood ratios are calculated from the sensitivity and specificity. Positive predictive value is the proportion of individuals with a positive test who have the disease; the value is much higher if the prevalence of the disease is high compared to if it is low. The converse is true for negative predictive values.
Posted on: Wed, 26 Feb 2014 05:32:49 +0000
Trending Topics
Recently Viewed Topics
© 2015