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Summary
If you’re involved with premarket submissions, you’re probably familiar with selecting a product code for your device and the resources available to select the appropriate one. And if your device is a prioritization or triage-related software used for radiological applications, which have been increasingly popular over the past several years, then you’ve likely debated over selecting the QFM or QAS product code.
Despite several resources being available, it can still be difficult to differentiate between these codes and determine which one actually applies to your device. Based solely on their definitions, both shown in the table below, it’s difficult to make an immediate distinction.
QFM vs QAS
While their definitions are almost identical, there are nuances in the technical method description that provide insight behind the differences between these product codes. The most telling difference is that the QFM product code includes performance requirements; with a >95% area-under-the-curve (AUC) target for sensitivity and specificity, the idea being since there’s less benefit to the prioritization it’s more important to demonstrate high accuracy to have an overall benefit to the device. Thus, devices classified under QFM tend to offer a passive notification strategy to end users rather than an active notification. Devices classified under the QAS product code tend to be less accurate but offer a quicker availability of results, thus are associated with more urgent findings.
Take, as a comparison, the following devices which have recently obtained 510(k) clearance:
QAS Product Code
- The Viz subdural hematoma (SDH) uses an artificial intelligence algorithm to analyze non-contrast CT images of the head for subdural hemorrhage and sends notifications to a neurovascular or neurosurgical specialist that a suspected subdural hemorrhage has been identified and recommends review of those images. The idea is that this device offers the ability to identify acute and chronic subdural bleeds, then quickly notify the care team to mobilize in case an immediate intervention is necessary.
QFM Product Code
- The Viz abdominal aortic aneurysm (AAA) uses an artificial intelligence algorithm to analyze CT angiogram images of the abdomen for the presence of an aortic aneurysm. It highlights studies with suspected abdominal aortic aneurysms in a standalone application for study list prioritization or triage in parallel to ongoing standard of care. The idea for this device is that it allows physicians to quickly and easily identify patients who have a suspected aortic aneurysm and take appropriate measures to prevent a future rupture. Its findings are not as urgent as the Viz SDH, described above.
CONCLUSION
Users can consider the following rule of thumb when deciding whether to classify their device under the QFM or QAS product code:
- QFM is intended for less urgent, but still time sensitive, and more accurate findings.
- QAS is intended for extremely urgent findings with less of an emphasis on accuracy.
The FDA’s 510(k) Premarket Notification Database [4] is always a great resource to search for devices under a specific product code. This database can be used to identify a previously cleared product(s) under a specific product code and use that as a starting point to establish your potential regulatory strategy. If there are further doubts, users always have the option of requesting a Q-Submission [5] to approach the FDA with specific questions related to determining a product code. Just keep in mind that it’s up to the user to already have a product code in mind and to be prepared with those specific questions to justify their product code selection to the FDA.
REFERENCES
[1] https://www.fda.gov/media/82781/download
[4] https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm
