Difference between revisions of "QIBA Concepts"
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Revision as of 21:45, 17 November 2016
- QIBA is an initiative sponsored by RSNA to advance quantitative imaging and the use of imaging biomarkers in clinical trials and clinical practice by engaging researchers, healthcare professionals and industry.
- Groundwork is research and validation coordinated by QIBA to understand things like sources of variance, quantify and prove some of the underlying assumptions and details of Profiles.
- A Profile is an implementation guide. A Profile defines a problem and tells each participating person or device what it must be capable of doing, and how it must be capable of interacting with the other people and devices in the profile to solve the problem.
- Actors are the people (such as radiologists or technologists) and devices (such as scanners or analysis software) on which a Profile specifies requirements (e.g. The technologist shall record the current patient weight at the time of each scan).
- Activities represent steps in the chain of preparing for and generating biomarker values (e.g. product validation, system calibration, patient preparation, image acquisition, image analysis, etc.). Activities are a convenience to organize committee analysis of factors affecting biomarker performance and to subdivide the profile requirements by step.
- A Claim is a statement of the technical performance of a biomarker that is expected if all the Actors generating the biomarker conform to the specifications in the Profile.
- Conformance to a Profile involves each Actor conforming to all the specifications assigned to it in the Profile.
- Conformance to most requirements is assessed by direct observation. Some requirements specify that a particular Assessment Procedure must be used. The assessment procedure defines how a test is run. The original requirement defines the pass/fail mark.
- A Checklist extracts the requirements from the larger Profile document and regroups them for convenient assessment of the corresponding Actors. In case of a discrepancy, the Profile is the normative document.
- A Conformance Statement document is a formal attestation that an Actor conforms to all the requirements as specified by a Profile.
- QIBA uses the term Conformance rather than Compliance.
- QIBA Profiles progress through a sequence of stages as they are developed. These Profile Stages represent increasing degrees of confidence and evidence supporting the biomarker performance expressed in the Claim.
- Validation is the process of assessing a biomarker and its measurement performance characteristics, and determining the range of conditions under which the biomarker will give reproducible and accurate data (ref). QIBA does not formally declare profiled biomarkers to be validated, however much of the QIBA profiling work, particularly at later stages, might contribute to validation.
- Qualification is the evidentiary process of linking a biomarker with biological processes and clinical end points (ref). Biomarkers are qualified for a specific context of use. QIBA does not qualify biomarkers but it is hoped that QIBA Profiles provide a good detailed guide for clear consistent implementation of a biomarker, that the QIBA Profile Claim (particularly after confirmed) contributes clear performance characteristics, that the QIBA Groundwork findings and data may be useful to the qualification process, and that the biomarkers selected for QIBA Profiles would be good candidates for qualification.