Diagnostic Devices with Intermediate/Gray Zone Output

• Activity Number: 410 - Diagnostic Tests: Regulatory Considerations of Intermediate Outputs and Oncology Screening, and Optimal Point of Heterogeneous ROC Curves
• Type: Contributed
• Date/Time: Tuesday, July 30, 2019 : 2:00 PM to 3:50 PM
• Sponsor: Section on Medical Devices and Diagnostics
• Author(s): Bipasa Biswas*
• Companies: U.S. Food and Drug Administration - CDRH
• Keywords: binary; intermediate zone; probability

Abstract

Medical diagnostic tests often provide a binary response- positive or negative result for a target condition. However, in some cases, the incorporation of a “gray Zone” or intermediate zone, leading to more than two results is recommended for clinical management. Using an intermediate/gray zone, to define a 3x2 table is appropriate than ignoring the test scores in these zones. The six-cell matrix (3x2 table), however, would serve limited purpose if clinicians cannot apply the additional information provided by the conditional operating characteristics to effect better patient management decisions. This presentation discusses a decision analytic approach utilizing pre-test and post-test probability to the target condition that can be used for efficient categorization of more than two results for such tests.