How to Proceed When a Testing Standard Doesn’t Exist

Scenario: You spent months and hundreds of thousands of dollars customizing a test method in verifying and validating the design of your new device. You included the data with your premarket submission to FDA, and their response is a list of questions as to why you think the test method is adequate and valid. You provide a rebuttal. The conversation circles on.

There will be times when current testing standards or guidance set by ISO, ASTM, ASME, AAMI, etc., don’t meet your company’s needs. How should you handle these situations? Brian Choules, Ph.D., Director of Testing at MED Institute, offered proactive recommendations during his OMTEC® 2015 presentation.

The best strategy: Ask a standard body to review and approve your test method.

This approach demonstrates industry leadership and controls the way the test method is designed and carried out.

“It’s quite possible that everyone else is struggling with the same question,” Choules says. “When you bring a group of people together to do this, you end up with a better standard and a better test method.”

A second advantage is that FDA is often involved in standards committees.

“FDA reviewers can take that information and share it among their colleagues, so that FDA gets a glimpse of best test methods. This can be valuable,” Choules says. “You build synergy when you use a collaborative effort like this. You get more companies following the same method, even before the standard is developed, and that leads to global acceptance.”

One disadvantage is that standards can take up to five years to be finalized.

The fastest strategy: Validate your test method.

You need to validate the test in order to understand its parameters and share that data with FDA.

“Some people think of validation as a black and white process—it is not. You’re not validated and then done; it’s a continuum,” Choules says. “The level of validation you need to accomplish for your test method is really commensurate with the risk associated with that test method. If you’re evaluating the color of a device it’s probably not as risky, so you don’t need to do much validation. If you’re validating the test method for the fatigue of a particular implant, the risk would be higher and more validation is needed.

“What are the advantages of validation? You understand the repeatability, the reproducibility, the uncertainty, the robustness; you understand the range of applicability, and then you can also understand the comparability or the bias of your method. It’s good to compare back to clinical data for validation. The disadvantages are that you’re working in a vacuum; there’s increased regulatory risk.”

At the basic level, the best way to validate a mechanical test, for example, is to start with an uncertainty analysis. Walk through the factors that could potentially affect the outcome and understand the sensitivity, Choules says. Then you must establish a monitoring sample so that when the test is performed in the future, you know what results are expected.

The unproven strategy: Join FDA’s Medical Device Development Tools (MDDT) pilot program.

The agency kicked off the MDDT program in 2013 to target clinical outcomes assessments, biomarker tests and non-clinical test methods.

“This is evidence that FDA was clearly frustrated with the time it was taking for standards to be developed; they wanted to make this happen quicker and take control of it,” Choules says. “No one knows if it’s going to work.”

Choules’ concerns are that the process doesn’t involve industry collaboration, and if the program is fully implemented, standards organizations might be less likely to spend time adopting test methods already qualified by FDA.

Companies and academia that participate in the MDDT program must make their test methods public, and in doing so, could sell them to others.

The complete presentation on Design Verification Testing can be downloaded here. Don’t miss the August issue of BONEZONE, which will delve more into device testing trends.

Carolyn LaWell is ORTHOWORLD’s Content Manager. She can be reached by This email address is being protected from spambots. You need JavaScript enabled to view it..