Overall risk acceptance criteria

mlo106

Registered
Dear all,
How do you set an overall risk acceptance criteria?

In my risk analysis plan I have decided to compare the medical device under evaluation to similar medical devices but notified bodies do not seem to like this methodology and prefer visual representation.
 

Ed Panek

QA RA Small Med Dev Company
Leader
Super Moderator
Comparisons are ok but not sufficient. The risk analysis must be discrete and unique to your own device. Design, Materials, Personnel, Tools, Customers, all vary so it must be an analysis that stands on its own.

Even if the comparable device is the predicate device, one must complete the analysis separately.

Mitigate all risks as much as you can. Whatever is left over needs to be Analyzed

"7.4 Benefit-risk analysis
If a residual risk is not judged acceptable using the criteria established in the risk management plan and further risk control is not practicable, the manufacturer may gather and review data and literature to determine if the benefits of the intended use outweigh this residual risk.'"


Remember risk control measures can introduce new risks. That must be addressed too. Imagine using lead shielding to prevent radiation. Lead is good for that but lead is also toxic. That needs to be controlled all on its own.
 

mlo106

Registered
Thank you Ed for your response,

Your response do not give me a methodology.

1) All risks have been reduced to an acceptable level
2) No unacceptable residual risk => no benefit-risk on individual risk to be performed as per ISO 14971
3) Overall residual risk acceptability has to be evaluated

The question is how to establish the criteria to confirm that the overall residual risk in relation to medical benefit is acceptable?

what I wanted to do is:
- consider that the residual risks are composed of side effects
- compare benefit and risks rates of the device to similar devices
=> the criteria is that the level of risk and benefit have to be comparable

or
-consider that the residual risks are composed of side effects
-perfom individual risk/benefit analysis
=> the criteria is define arbitrarily as a % of unfavorable benefit / risks ratio that would be acceptable

How do you operationnaly do it?

Thank you in advance
 

yodon

Leader
Super Moderator
notified bodies do not seem to like this methodology and prefer visual representation.
Hmm... sounds like they're edging into consulting! First, ask them to show you the requirements.

That said, 24971 does give some suggestions, factoring in aspects like both patient and caregiver perspectives. To me, it's like making a legal case for being acceptable. Certainly not sure how that could be represented visually.

We also do a heat map of all the final risk scores. That can be represented visually, but, to me, seems to be a bit weak in terms of justifying. But it can be colorful and visually pleasing. :)
 

Ed Panek

QA RA Small Med Dev Company
Leader
Super Moderator
Thank you Ed for your response,

Your response do not give me a methodology.

1) All risks have been reduced to an acceptable level
2) No unacceptable residual risk => no benefit-risk on individual risk to be performed as per ISO 14971
3) Overall residual risk acceptability has to be evaluated

The question is how to establish the criteria to confirm that the overall residual risk in relation to medical benefit is acceptable?

what I wanted to do is:
- consider that the residual risks are composed of side effects
- compare benefit and risks rates of the device to similar devices
=> the criteria is that the level of risk and benefit have to be comparable

or
-consider that the residual risks are composed of side effects
-perfom individual risk/benefit analysis
=> the criteria is define arbitrarily as a % of unfavorable benefit / risks ratio that would be acceptable

How do you operationnaly do it?

Thank you in advance
Lets try this stepwise

Have you identified and reduced all known risks within the acceptable limits (THAT YOU AS OEM) have defined?

It is important to note that the standard does not define acceptable levels of risk for medical devices - this is left to the manufacturer to determine as part of their risk management processes. You the OEM are THE SUBJECT MATTER EXPERTS WRT to your own device.
 

Tidge

Trusted Information Resource
This response cannot be taken to the bank, but I believe the most appropriate thing to currently do is (as suggested by @Ed Panek ) is to identify and knowingly reduce all risks, as much as possible and that the benefits outweighs these risks (my addition).

In an earlier regime of medical device risk management, there was a typical starting point of establishing risk acceptability "limits" first and then doing the risk management and making sure "all risks are acceptable". As many people figured out, this can sound a little like letting the runner decide the length of the race before the starting pistol is fired... and I'm sure there are examples of runners who'd want to change the distance mid-race!

I think it is still valuable to have a priori established acceptability targets, because having something like a stationary target provides a zeroth order assessment on the device and its ultimate safety profile. However: in the modern sense of medical device risk management I believe it is necessary to evaluate individual risks as acceptable, and not rely on something like mathematical hokum that says "for all risk lines N1 < N0, so the product is acceptable". I want to be practical, there are many devices that don't have acceptable risks but the risks can still be controlled while providing enormous medical benefits in certain circumstances.

Admitted personal defect follows: I could never grok how some companies could have both an a priori established set of risk acceptability criteria AND have a self-allowance to market devices that had risks that included unacceptable risks. I saw a lot of hand-waving, rationalization, and goalpost-moving and it always struck me that it was pretending that a priori criteria were somehow set in stone was the issue.
 

d_addams

Involved In Discussions
Yes, as I said before all risks have been reduced to an acceptable level.
are you able to demonstrate this objectively or are you just stating that based on a qualitative 'belief'. This may be what the reviewer is getting at, how have you determined that the risks are at an acceptable level. If your risk acceptability criteria were stated in context of some type of quantitative profile of risk categorizations this could be depicted visually (and may be something they have seen previously).
 

Ed Panek

QA RA Small Med Dev Company
Leader
Super Moderator
Make sure you are comfortable talking about risk and the work you have done so far.

Nothing creates doubt like doubt.
 
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