Accuracy of Two Screening Tests Administered in Series Consider a population in
ID: 3358892 • Letter: A
Question
Accuracy of Two Screening Tests Administered in Series
Consider a population in which there are 500 diabetic individuals among a total population of 10,000.
A, Calculate the sensitivity and specificity of the blood sugar screening test, and interpret each of these values in one sentence.
For each calculation, report the numerator and denominator, and provide your answer as a percentage.
B, Calculate the predictive value positive and predictive value negative of the blood sugar screening test, and interpret each of these values in one sentence.
For each calculation, report the numerator and denominator, and provide your answer as a percentage.
Diabetes Blood sugar screening test + - Total + 350 1900 2,250 - 150 7600 7,750 Total 500 9500 10,000Explanation / Answer
A)sensitivity=350/500=0.7 ~ 70%
sensitivity reflects probability of a person to be tested positive for diabetes given person have diabetes.
specificity =7600/9500=0.8 ~80%
specificity reflects probability of a person to be tested negative for diabetes given person doesnot have diabetes.
B)predictive value positive =350/2250=0.1556 ~15.56%
posiitve predictive value reflect probability of aperson to have disease given test result comes positive.
predictive value negative =7600/7750=0.9806~ 98.06%
negative predictive value reflect probability of aperson not to have disease given test result comes negative.