Diagnostic power of the test is reflected by -
Ans. is 'c' i.e., Predictive value Predictive accuracy (Predictive value) of screening testo In addition to sensitivity and specificity, the performance of screening test is measured by its predictive valueo Predictive value reflects the diagnostic power of the test.o Predictive value depends upon sensitivity, specificity and prevalence.i) Positive predictive value (Post test probability of a disease or precision rate).# It is the probability a patient with positive test result has the disease in question, i.e., the proportion of patients with positive test results who are correctly diagnosed.# In other words, it is the precentage of the diseased people among those who show positive results.# For example, if positive predictive value of a test is 50%, that means there is 50% probability a patient with positive tests results has the disease.# A high positive predictive value indicates that a person with a positive test has the disease - diagnostic power of a screening test to correctly identify the disease.# It is the most important measure of a diagnostic method as it reflects the probability that a positive test reflects the underlying condition being tested for.ii) Negative predictive value# It is the probability that a person with negative test results, is infact healthy.# In other words the percentage of healthy people among those who show negative test results.# A high negative predictive value means there is high probability that a negative test rules out the disease - diagnostic power of a screening test to exclude the disease.o The sensitivity and specificity are properties of the screening test, while the predictive value is property of both the test and the population under study.
Sensitivity
Specificity
Predictive value
Population attributable risk
Screening for Disease