Operational Validity in Decentralized Molecular Point-of-Care Diagnostics: A Human Factors Engineering Perspective.

Area of Science:

• Medical Diagnostics
• Human Factors Engineering
• Health Systems Science

Background:

• Molecular point-of-care (POC) diagnostics are increasingly used by non-expert users in decentralized settings.
• Traditional evaluations overlook human-system interactions, impacting real-world diagnostic reliability.
• Existing usability principles are fragmented and lack a lifecycle-based framework.

Purpose of the Study:

• Introduce and define Operational Validity for POC diagnostics.
• Compare Operational Validity with traditional evaluation dimensions and post-market metrics.
• Propose a lifecycle-based framework for ensuring diagnostic performance in real-world use.

Main Methods:

• Comparative analysis of Operational Validity against existing frameworks.
• Synthesis of international standards (IEC 62366-1) and FDA guidance.
• Analysis of molecular workflow complexities and use-related failure modes.
• Examination of human factors engineering (HFE) and usability testing.

Main Results:

• Operational Validity is defined as the ability of a diagnostic system to maintain intended performance with intended users in real-world environments.
• A formalized, lifecycle-based Operational Validity framework is proposed.
• HFE and usability engineering are foundational to achieving operational validity.
• Iterative usability testing is crucial for mitigating use-related risks.

Conclusions:

• Operational Validity is essential for translating the analytical sensitivity of molecular POC tests into consistent clinical utility.
• A lifecycle approach to HFE, including design, validation, and surveillance, is necessary.
• Ensuring operational validity is critical for the safe and effective expansion of POC diagnostics.