Risk Severity Estimation for Medical Devices as per ISO 14971

N

nussehund

#1
Dear Everyone,

When estimating the severity of a risk I often find that there are multiple possible outcomes (severities). Obviously, the conservative thing to do would be to go with the worst case but what if the worst case is not very likely?

How do you guys handle this? Do you go with the average case? the worst case? do you split the risk into two different risks?

The reason that I am asking is that I am analyzing a risk where part of a device breaks off and hits the patient. In most cases this is unlikely to cause serious harm but if "the stars are right" permanent injury or even death could be a possibility. Assigning a severity of "catastrophic" to the risk is not without problems ...

Thanks!
Nusse
 
Elsmar Forum Sponsor

Jen Kirley

Quality and Auditing Expert
Staff member
Admin
#2
Welcome to the Cove!

Not being a medical device person myself, I will suggest you try looking at the similar threads shown at the bottom of this page.

I hope this helps!
 

Marc

Fully vaccinated are you?
Staff member
Admin
#3
I'm not a medical device person myself either, and I do not have a copy of ISO 14971, but in automotive and aerospace I always go with "worst case" when assessing "severity". If you have multiple outcomes, split the risk and address individually. If you do not, you better have a statistically valid reason (among other things) why you didn't because if the impossible happens (struck by lightning comes to mind, as does the GM ignition switch fiasco) you'll have a lot of explaining to do. I think the old saying is "better safe than sorry".
 
P

pldey42

#5
I understand that when Disney do an annual service on a rollercoaster they take it completely apart, inspect and replace things as necessary, then reassemble it. The first people to test-ride it are the maintenance team including the manager.

So for me the tests are: would I allow my child to be the patient? And would the CEO allow her child to be the patient?

Just 2c
Pat
 
N

nussehund

#6
Thanks you for the answers!

Splitting a risk to address the different scenarios based on the severity of harm and analyzing them individually sounds like a promising idea.

I could conclude that for a given event a "serious" outcome is "unlikely" and that a "catastrophic" outcome is "improbable". Both risks would be acceptable according to my acceptance criteria. Fantastic :)

But is this approach acceptable ???

One could argue that because the difference in probability hinges only on issues related to exposure that the different outcomes for the event must be treated as one risk?

If this is not so, then it would be possible to postulate that because each actual incident will be different, the probability component should be considered in relation to a single interaction with the equipment rather than with total amount of interactions over the cause of the equipment's lifetime.

At the very least this would be something that should be considered during "residual risk assessment"?
 

sagai

Quite Involved in Discussions
#7
I do not know how happy I would be to participate in an extremely rare case when a improbable catastrophic event does happen ... :cool:

Assessing probability is wordsmithing for me, it is subjective, up to the assessment team, up to cultural and educational background, etc. I see no real benefit of emphasising too much on probability to be honest.

Cheers!
 
M

medgar

#8
If you calculate 'probability' in with the severity aren't you then "double dipping" on 'Likelihood' in your risk assessment?
 
#9
Hello Nusse.

Score the worst case scenario against the likelihood of the event
This is all about reasonably foreseeable sequences of events following the identification of hazards and not unlikely sequences. :agree1:
 
M

MedTechSoftware

#10
Risk is made up of two factors - severity and probability. Both have to be considered when evaluating risk, so a risk with high severity, but extremely low probability might be considered acceptable. It is the responsibility of senior management to determine criteria for acceptability of risk. Also, in the EU, the Medical Devices Directive requires that all risks are reduced "as far as possible" taking account of the "generally recognised state of the art".

There is also the relationship between a hazard, a hazardous situation and harm. An example of this might be a shark in a swimming pool is a hazard; a person getting in the pool with the shark is a hazardous situation and the person being attacked by the shark is a harm. Each of those occurrences has a lower probability than the one preceding it. Someone might not get into the pool if they know a shark is in there and even if they do, the shark might not be hungry.
 
Thread starter Similar threads Forum Replies Date
S The Severity of a Medical Device Hazard - Risk Analysis Clarification ISO 14971 - Medical Device Risk Management 6
MrTetris Informational Risk Register - Same hazardous situation, different severity of harms ISO 14971 - Medical Device Risk Management 7
F Risk = Likelihood * Severity - Can we mitigate the Severity? Occupational Health & Safety Management Standards 44
E Risk Management selection Probability of Occurrence and Severity ISO 14971 - Medical Device Risk Management 24
T IEC 62304 : Risk control for SaMD IEC 62304 - Medical Device Software Life Cycle Processes 8
T Risk Assessment and Management Misc. Quality Assurance and Business Systems Related Topics 0
P Scenario based risk assessment IEC 27001 - Information Security Management Systems (ISMS) 1
Q KPI risk assessment - Criteria for the given score IATF 16949 - Automotive Quality Systems Standard 3
S Foreign Risk Notification Canada Medical Device Regulations 2
J HELP NEEDED ! Risk Management Exercise ISO 14971 - Medical Device Risk Management 12
O Should a Covid vaccine and testing policy be included as part of ISO9001 or AS9100 risk management? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 6
M Does 4.5 - Alternative RISK CONTROL apply to the Particular Standards? IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
Q Measurement Equipment Revocation - Looking for a Disposal Form with Risk Assessment IATF 16949 - Automotive Quality Systems Standard 10
B ISO13485 Risk managment implementation for suppliers ISO 14971 - Medical Device Risk Management 2
Moncia Chemical risk assessment / COSHH Manufacturing and Related Processes 5
E Supply chain main policies ,scope, risk assessments & relavant KPI Supply Chain Security Management Systems 2
D Use Error Risk Controls and Control Verification ISO 14971 - Medical Device Risk Management 6
J Risk Assessment of Lithium Ion Batteries FMEA and Control Plans 3
Melissa Risk Management Process, How far do I need to go? ISO 14971 - Medical Device Risk Management 13
D Does Risk Management apply to re-labeler (MDR) EU Medical Device Regulations 1
H Risk Management Plan in agile process ISO 14971 - Medical Device Risk Management 14
H Risk Analysis and Probability of Occurrence ISO 14971 - Medical Device Risk Management 3
B Risk analysis for defective measuring or measuring equipment out of calibration General Measurement Device and Calibration Topics 2
P Benefit risk analysis on pFMEA ISO 14971 - Medical Device Risk Management 9
B AS9102 - 3D printing a special tool required for assembly (counterfeit risk?) AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 12
K Defining risk control measures IEC 62304 - Medical Device Software Life Cycle Processes 14
U Supply risk management Manufacturing and Related Processes 4
T Biological Evaluation (10993) & Risk Management ISO 14971 - Medical Device Risk Management 9
D Cybersecurity and Risk Management: Loss of confidentiality IEC 62304 - Medical Device Software Life Cycle Processes 5
Q FMEA and Risk assessment in Microsoft Access FMEA and Control Plans 6
I Realization processes input into overall risk ISO 14971 - Medical Device Risk Management 2
M Need Help With Information Security Asset Risk Register IEC 27001 - Information Security Management Systems (ISMS) 2
thisby_ Post Market/Production Risk Assessment ISO 14971 - Medical Device Risk Management 0
S Risk Management Review ISO 14971 - Medical Device Risk Management 4
D Low risk IVD study in the UK, do I need MHRA approval? UK Medical Device Regulations 1
S Risk Management and other Files ISO 14971 - Medical Device Risk Management 8
silentmonkey Overall Benefit/Risk Analysis - Risk Management VS Clinical Evaluation ISO 14971 - Medical Device Risk Management 3
N ISO 27001 for Jumb Burger - Risk Assessment sheet IEC 27001 - Information Security Management Systems (ISMS) 11
C Risk Assessment Tools ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 3
qualprod Examples to mitigate risk from Covid ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7
G Risk of stopping your customer's line IATF 16949 - Automotive Quality Systems Standard 4
C Risk Matrix vs FMEAs ISO 14971 - Medical Device Risk Management 12
S IVD risk class II devices for Brazil and MDSAP Other Medical Device Regulations World-Wide 0
M ISO 14971:2019: Criteria for overall residual risk ISO 14971 - Medical Device Risk Management 11
M ISO14971:2019 - Verification of implementation and effectiveness of risk control ISO 14971 - Medical Device Risk Management 5
Aymaneh Medical Device Cybersecurity Risk Management IEC 27001 - Information Security Management Systems (ISMS) 2
S Traceability of requirements to design and risk Design and Development of Products and Processes 3
R Risk control measures as per ISO 14971 ISO 14971 - Medical Device Risk Management 6
D Deciding whether or not pre-market clinical investigation is required for low risk device EU Medical Device Regulations 5
R The term "Benefit Risk Ratio" in EU MDR, do I need to present benefit risk analysis as a RATIO Risk Management Principles and Generic Guidelines 4

Similar threads

Top Bottom