II. Definition

  1. Receiver Operating Characteristic (ROC)
    1. Graphical representation of balance between Test Sensitivity and Test Specificity
  2. Test Criterion
    1. Threshold for which a test is considered positive
    2. A Screening Test may set the test criterion low to minimize false negatives (at the expense of increased false positives)
    3. A confirmatory test may set the test criterion high to minimize false positives (at the expense of increased false negatives)

III. Technique

  1. Given a range of test criteria (from low threshold to high threshold)
    1. Identify the Test Sensitivity and Test Specificity at each of the test criteria
  2. For each test criteria, plot the Test Sensitivity and 1-Test Specificity
    1. True Positive Rate (Test Sensitivity)
      1. Plot on Y axis
    2. False Positive Rate (1-Test Specificity)
      1. Plot on X axis

IV. Interpretation

  1. Identify the Shoulder or inflection point in the curve as the optimal threshold
  2. Best tests have maximal area under the curve (AUC)
    1. Most distinct, highest inflection point best distinguishes between positive and negative test
    2. Poor tests, have no inflection point
      1. Flat, linear relationship between Test Sensitivity and 1-Test Specificity at various test criteria

V. Resources

  1. Receiver Operating Characteristic (Wikipedia)
    1. https://en.wikipedia.org/wiki/Receiver_operating_characteristic

VI. References

  1. Desai (2014) Clinical Decision Making, AMIA’s CIBRC Online Course

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