Explore BrainMass
Share

Explore BrainMass

    Sensitivity, specificity and predictive value

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Please see the attachment.
    12. Table 1. Results of a screening test for diabetes, using a cutoff point of 160 mg.dl.

    True Diagnosis
    Test result Diabetic Not Diabetic Total
    Positive 34 20 54
    Negative 116 9,830 9,946
    Total 150 9,850 10,000

    The specificity of the screening test for diabetes is

    a. 0.3%

    b. 22.6%

    c. 63.0%

    d. 77.4%

    e. 99.7%

    Save Answer

    13. The sensitivity of the screening test for diabetes is

    a. 0.3%

    b. 22.6%

    c. 63.0%

    d. 77.4%

    e. 99.7%

    Save Answer

    14. The positive predictive value of the screening test for diabetes is

    a. 0.3%

    b. 22.6%

    c. 63.0%

    d. 77.4%

    e. 99.7%

    Save Answer

    15. If the cutoff is set higher than 180 mg/dl, how would this affect the sensitivity and specificity?

    a. no changes

    b. sensitivity increase, specificity decrease

    c. sensitivity decrease, specificity increase

    d. both decrease

    e. both increase

    Save Answer

    16. What will be the effect on false negatives (FN) and false positives (FP) of setting the cutoff higher than 180 mg/dl?

    a. FP increase, FN unchanged
    b. no changes

    c. FP increase, FN decrease

    d. FP decrease, FN increase

    e. both decrease

    Save Answer

    17. When the screening cutoff point was lowered to a blood glucose value of 130 mg/dl, 164 persons now tested positive; 98 of these people were among the 9,850 persons judged by diagnostic tests not to have diabetes. Compute the sensitivity, specificity and predictive value of a positive test at this cutoff level in the next 3 questions Sensitivity is

    a. 1%

    b. 40%

    c. 44%

    d. 56%

    e. 60%

    f. 99%

    Save Answer

    18. Specificity is

    a. 1%

    b. 40%

    c. 44%

    d. 56%

    e. 60%

    f. 99%

    Save Answer

    19. Positive predictive value is

    a. 1%

    b. 40%

    c. 44%

    d. 56%

    e. 60%

    f. 99%

    © BrainMass Inc. brainmass.com October 9, 2019, 9:23 pm ad1c9bdddf
    https://brainmass.com/statistics/descriptive-statistics/sensitivity-specificity-and-predictive-value-183337

    Attachments

    Solution Preview

    Please see the attachment.

    12. (Points: 2)
    Table 1. Results of a screening test for diabetes, using a cutoff point of 160 mg.dl.

    True Diagnosis
    Test result Diabetic Not Diabetic Total
    Positive 34 20 54
    Negative 116 9,830 9,946
    Total 150 9,850 10,000

    Condition is
    Present Absent Total=
    Test is Positive True Positive=34 False Positive=20 54
    Negative False Negative=116 True Negative=9830 9946
    Total= 150 9850 10000

    The specificity of the screening test for diabetes is

    a. 0.3%

    b. 22.6%

    c. 63.0%

    d. 77.4%

    e. 99.7%

    Answer: e. 99.7%

    Specificity = True Negatives/ (False Positive + True Negative)
    = 9830 / (20 + 9830) = 99.7 %

    13. (Points: 2)
    The sensitivity of the screening test for diabetes is

    a. 0.3%

    b. 22.6%

    c. 63.0%

    d. 77.4%

    e. 99.7%

    Answer: b. 22.6%

    Sensitivity = True Positives / (True Positives + False Negatives)
    = 34 / (34 +116) = 34 /150 = 22.6 %

    14. (Points: 2)
    The positive ...

    Solution Summary

    The solution calculates sensitivity, specificity and predictive value

    $2.19