The FDA is responsible for ensuring the safety of biomedical devices that are available in the United States. Precision and accuracy are both factors that affect how doctors and patients will react to results from a medical instrument, and so both are vital to ensuring safety standards. Accuracy is how close an instrument’s result is to that of a reliable “gold standard.” It is incredibly vital because an inaccurate measurement can lead to an inaccurate diagnosis. Misdiagnoses can result in wrong treatments, which can result in poor patient outcomes.

Precision is concerned with the differences in results for a set of measurements, regardless of the accuracy. According to the FDA, precision is related to uncertainty meaning that the instrument in question needs to be able to repeat results consistently in order to reduce the uncertainty of future results independent from its accuracy. This is important because an instrument that provides different results each time it is used is not very useful. Analytical validation must be conducted on all medical instruments to check for Precision, including repeatability and reproducibility.

Over time, both precision and accuracy for instruments “drift,” causing instruments to become both less accurate and less precise. For this reason, the FDA also has safety standards related to equipment calibration, so that original instrument performance is maintained. Based on standards for all of these things, FDA often engages in product recalls. Do any of you know of any FDA recalls specifically for poor accuracy or precision for a medical device?

In agreement with what Ibraheem stated above, Precision and Accuracy are most at risk with aging devices as use brings wear and fatigue. Part 21 CFR 820.72 of the FDA Medical Device regulations defines the rubric for calibration standards. proper calibration is not just dependent on the upkeep of the device, it must be considered during the design process as well. consider an simple caliper for example. a cheap potentiometer, poor sliding mechanisms or locks, or even a misplaced access port that can introduce dust into the system can cause faulty calibration and therefore need for repair. I believe much emphasis should be placed on designing products that require minimal upkeep and minimize part replacement cost so that maintaining FDA standards for calibration is simple and inexpensive for the user.

Hello All,

While searching for the accuracy and precision over the internet, I came across a very interesting blog :

Check the following link where people discuss about accuracy, reliability safety and regulations from other countries.They have explained multiple examples of medical devices and their drawbacks as well.

https://www.researchgate.net/post/How_do_you_know_that_medical_devices_are_reliable_accurate_and_safe2

Phil Petursson
Phil Petursson
How do you know that medical devices are reliable, accurate, and safe?

How do you know that medical devices are reliable, accurate, and safe?
I would like to evaluate several medical devices (for example: therapeutic ultrasound unit, interferential unit, cardiac defibrillator, laser therapy unit, etc.). The evaluation would include the reliability, accuracy, and safety of the medical devices. This would be important contributing to best practice procedures.
For example, I looked at AED (Automated Electronic Defibrillator) info by checking the FDA site: http://www.fda.gov/default.htm
There are numerous defibrillators that are not approved/registered by the FDA. And several approved/registered units, have been recalled by the FDA, due to serious problems. Therefore, I thought the FDA is a very credible site to obtain an independent evaluation of medical devices.
I believe that approval ratings that include: 'CE', 'UL', and 'GS' are only electrical safety ratings, and do not evaluate the reliability and validity (accuracy) of a medical device. I believe that ISO certification generally refers that a manufacturer "has introduced and applies a Quality Management System"; "demonstrated compliance of the Quality Management System" related to a particular area/code/regulation/policy. This information does not readily show reliability, accuracy, safety of a product. And, any claims by the manufacturer could be prone to internal bias. This is where independent evaluations by the FDA provides strong, credible evidence. And, I noticed that several medical devices state that they are FDA approved/registered. However, medical devices are regularly sold without FDA approval/ registration.
Please let me know if I am mistaken with any information, and provide further advice.
Why would a manufacturer of a medical device not obtain FDA approval/registration? I believe that FDA approval would be an exceptional selling feature.
Is it best to choose a medical advice on the basis of FDA approval and registration?
Or are there other regulatory bodies that provide a recognised standard of approval?
I hope that this information would be helpful to share with all health/medical practitioners.
Cheers, Phil
Topics

Medicine
May 16, 2012
Recommend5 Recommendations
Popular Answers
Rahul Dimber
Rahul Dimber · Frimley Park Hospital NHS Foundation Trust
There is the fundamental problem in classification of medical device.Current classification is risk based-which is more of an engineering concept applied to medical field.This makes the device assessment more confusing.There are more than 100,000 medical devices on market compared to around 10,000 medicinal product.The current regulatory system is not is a position to assess each and every medical device placed on the market.There is a need for development of regulatory system which can evaluate medical device for its efficiancy and effectiveness.
Jun 1, 2012 · Recommend8 Recommendations
Steven Bellistri
Steven Bellistri · Mercy Health System
My advise is to first look to FDA approved devices and those with the CE for European devices. Those are more then electrical. Then I look to those that meet my budget, are easy to use, and have support from the manufacture. Then do a side-by-side comparison to make your choice.
May 6, 2013 · Recommend5 Recommendations
All Answers (90)
Phil Petursson
Phil Petursson ·
Thank you for the info. Http://www.hc-sc.gc.ca/index-eng.php is an excellent site, and I found that the site is strongly correlated with the FDA. I have contacted Health Canada regarding: How to confirm if medical devices are reliable, accurate, and safe? The situation is that I find several medical companies are promoting medical devices without an established standard of valid and reliable evidence. Best evidence would be with independent testing/ approvals from appropriate medical organisations or regulatory bodies. I believe this is an important topic. I'll post my updates as I receive info.
Regards,
Phil (New Zealand)
May 16, 2012 · Recommend1 Recommendation
Lava Kafle
Lava Kafle · Kathmandu University
Great for healthcare entrepreneurs researchers like me thanks
May 16, 2012 · Recommend1 Recommendation
Arnaldo Guimarães Batista
Arnaldo Guimarães Batista · New University of Lisbon
And as far as I know non-CE marked device is not marketable in the European Union, right?
May 16, 2012 · Recommend1 Recommendation
Conrad Wall
Conrad Wall · Massachusetts Eye and Ear Infirmary
Potential investors might be put off unless your device did have some kind of certification. This is true in the US in my experience.
May 16, 2012 · Recommend1 Recommendation
H.-J. Cappius
H.-J. Cappius · W.O.M. World of Medicine GmbH
In Europe the CE mark is needed for marketing a (medical) product, as it signifies the conformation with the EC-wide harmonized standards.
But also researchers need a simplified EC conformation just to use a medical device in clinical research settings..
May 16, 2012 · Recommend1 Recommendation
Arnaldo Guimarães Batista
Arnaldo Guimarães Batista · New University of Lisbon
That explains the labelling "for research purposes only" . No clinical treatment based upon on the device outputs
May 16, 2012 · Recommend1 Recommendation
Patrice Forget
Patrice Forget · University Hospital Brussels
I agree that the CE mark is needed for safety issues. But it does not imply that the device is reliable/accurate and certainly not that it makes sense from a clinical point of view. The only way is to critically analyse the published litterature.
May 16, 2012 · Recommend1 Recommendation
Arnaldo Guimarães Batista
Arnaldo Guimarães Batista · New University of Lisbon
defibrillator history confirms that: certified devices going wrong...

I find that, many times, there is a gap between state-of-the-art research and the certified corresponding systems. At least in my research area (biomedical signal processing). By the time the systems hit the hospital, the algorithms might be just not up-to-date...
May 16, 2012 · Recommend1 Recommendation
Sabine Sabouraud
Sabine Sabouraud · Centre Hospitalier Universitaire de Lyon
In France, the manufacturer himself has responsibility for putting on the market a medical device. First, the CE mark must be given, before putting on the market, that is evidence of its agreement with health and safety European requirements. The French health Authorities, called Afssaps, becoming ANSM at present (www.ansm.sante.fr), intervenes after, doing the surveillance (safety).
I personally fit the Lyon city out with AED, and the duration of guaranty is 7 years now, instead of 5 years. The problem is maintenance, servicing.
Best regards
Sabine
May 17, 2012 ·

Precision and accuracy play critical roles in medical device development as it is these factors that determine the validity of what a device claims to do. The FDA has guidelines that refer to calibration measures for instruments and such. In addition, in the case of instrumentation, the device in question has to produce consistent outputs with respect to the "golden standard" the FDA sets out. Things like a device's measurement resolution can also play into this depending on the application, but no matter what, it still has to meet FDA standards; otherwise the company risks shutdown and even legal repercussions. The reason things like accuracy and precision is so important to the FDA is because a lack of accuracy and precision in devices can result in a misdiagnosis and other preventable complications.

The importance of accuracy and precision when it comes to the FDA stems from concerns over safety. If a device or drug is not accurate or precise, there is no way the FDA can allow that level of variability and unknown be used by the general population. Additionally, precision and accuracy are needed if a new device or drug is to be used over a well established treatment methodology. That is not to say that this will eliminate complications or side effects, but more so to establish the consistency of these unwanted effects as much as the desired effects.

Precision and accuracy are two valuable pillars of judgement that are often overlooked by consumers. How well these two conditions are met can significantly impact the ruling presented by the FDA on any medical device, substance or product. If precision and accuracy are not met properly by a commonly used medical device, it can often lead to a misdiagnosis for patients, which can prove to be fatal. There have been many instances where the FDA has ordered a recall of medical devices due to its lack of precision and accuracy. On June 8th, 2017 a recall was initiated by the FDA on a 3D revascularization device produced by Penumbra inc. During the surgical implant of this device, there was a risk of the delivery wire breaking or separating during use. As a result, fractured pieces of the delivery wire could be left inside the patients brain. This led to many serious adverse health effects on the patients. This example showed that although the device precisely served its purpose, it wasn't able to prove itself to be accurate. Although all case of precision and accuracy may not be this severe, this shows how imperative it is for all medical devices to follow their guidelines as best as possible.

reference: https://www.fda.gov/medicaldevices/safety/listofrecalls/ucm567913

Accuracy, as stated above, is an evaluation of the device to measure it up to existing standards. Precision evaluates the device against itself. Accuracy comes into play with the initial acceptance of the device. In order to accept the device, it should be confirmed that it complies with existing standards. The accuracy of the device qualifies how it performs in comparison to existing values.
Precision is the next step before completely accepting the device, as it must be confirmed to be consistent with itself. With precision, the FDA will evaluate if the device is properly functioning not just the first or third or last time it is tested but every time. The values attained must continue to hit the standard achieved with accuracy. For a medical device to be officially accepted, it must hit both accuracy and precision.

They are both important to the FDA, because these are the numbers that decide if the device is going to work and how well will it work. For example, if you are inventing a device for chemotherapy it is must to know if the machine is accurate and precise. Because if either one is bad and the FDA cannot pass the device because device could harm or perhaps even kill people.

I agree that precision and accuracy are both important when it comes to the FDA and regulating medical devices. Accuracy and precision are both important actors for medical devices - when used on patients the medical device may need a certain degree of accuracy and precision in order for its intended use. Precision and accuracy are two important concerns for the FDA for medical devices.

Accuracy and precision play important role when it comes to FDA and their rules and regulations. I think they main reason they are important is to make sure any medical device is consistent and there is no adverse effect on the patient. Any medical device needs to pass through accuracy and precision or else it cannot pass the validation of that particular device.

"It’s also a common practice to check the accuracy and precision of laboratory equipment whenever a new instrument is brought into the lab, when equipment is suspected of being damaged, and on a periodic schedule thereafter. In addition, accuracy and precision checks are frequently used as part of the qualification process of a new laboratory technician."
Source:
Defining Accuracy and Precision | Quality Digest. (2017). Qualitydigest.com. Retrieved 2 October 2017, from https://www.qualitydigest.com/inside/fda-compliance-article/defining-accuracy-and-precision.html

The manufacturing of a product should only be allowed if precision and accuracy are guaranteed. When some doctor or medical personnel goes to use a device they should be utterly sure that it is going to work exactly how they are expecting a device to work. Products are seen to have a huge mark up if you look at just the overhead cost of the products material. This up charge is also to cover the expenses of all the products that are discarded for not being able to meet these regulations. Devices are checked continuously throughout their production to make sure these goals are met and maintained

In the medical device department I think that accuracy is making sure the device will perform the necessary actions that it is set out to do, and precision is making sure that the test results you get are consistent with each other and that you are not getting any extreme results or findings in your research. Accuracy is important because if a device or drug does not perform the way it is intended to, then it is useless and will not be bought on the market. Precision will convince the FDA and the user that the drug will most certainly always work, that is reliable to use, and that it will not cause any risky side effects that are not anticipated for. They are so important to the FDA because if you can not prove that your device actually meets the description set out for it then it will not be approved, as the results do not meet the intended use. Precision is important because the FDA wants to see that the device will always work no matter who it is used on or implanted in. If the device shows it will only work half of the time then the FDA will not accept it because of the risk of unanticipated side effects. Pre-Clinical and Clinical trials show that a device is accurate in its results and that the results are precise and consistently around the same desired results.

Accuracy is a measure how closely your product meets a specified standard or criteria. Precision is a measure how reproducible your results are, whether your product performs consistently across a group of customers. The FDA tries to optimize quality of medical devices by focusing on these two aspects of a product. If a product performs inaccurately, then no one will buy the product and this will hurt the business. It will also hurt the business if the desired result isn't reproduced across most scenarios. It won't matter if the product can performed ideally because more than person is buying this product, so it has to be consistent in maintaining that standard when people use it. Ideally, the product will be both accurate and precise in performance. However, this is a difficult task that many companies struggle with, which is why they have employers who do risk/error analysis on their products to find ways to lower the amount of defects in their products by changing an aspect of a process of some external factor.

In terms of medical devices, accuracy measures how closely certain data fall into the acceptable ranges of operation. If this does not hold true for the device, the device may not perform as intended. Precision requires the device to perform in a similar way consistently so that the same results are produced every time. The FDA requires medical devices to be both accurate and precise so that people using them are effectively getting the drugs/treatment/aid they need.