Testimony of Dr. Anna E. Mazzucco on Classification of Stair-climbing and Mechanical Wheelchairs

By Anna E. Mazzucco, Ph.D.

December 12, 2013


My name is Dr. Anna Mazzucco, and I thank you for the opportunity to speak today on behalf of the NationalResearchCenter for Women and Families.   After completing my Ph.D. in at HarvardMedicalSchool, I conducted research at the National Institutes of Health.  Those are the perspectives I bring today.

Our nonprofit organization conducts research, analyzes data from the research literature, compares the risks and benefits of comparable medical products, and also explains the evidence so that it is understandable to patients and providers.  Our president is on the Board of Directors of the Alliance for a Stronger FDA, which is a nonprofit dedicated to increasing the resources that the FDA needs to do its job.  Our organization does not accept funding from medical device companies, and therefore I have no conflicts of interest.

We recognize the incredible value of stair-climbing wheelchairs for consumers.  For this reason, we want to make sure they continue to be held to the highest safety and quality standards.  Stair-climbing wheelchairs are have been considered high risk – Class III – and have been required to submit studies of safety and effectiveness under the PMA review process.  The proposed order being considered today would reclassify stair-climbing wheelchairs into Class II indicating moderate risk, and reviewing it through the 510(k) process.  If FDA makes that decision, no studies of safety or effectiveness would be required or available.  If that happens,  patients and their families could not make informed choices about which stair-climbing wheelchairs are best.  In addition, if they are down-classified, no pre-market inspections of the manufacturing facilities would be conducted prior to putting the new wheelchairs on the market.

While we care deeply about innovation and access, we do not want those to come at the cost of safety or quality.  There are 55 adverse events reported for stair-climbing wheelchairs in the Manufacturer and User Facility Device Experience (MAUDE) database, with the most common events being falls and fractures.  This should be unacceptable, since the entire purpose of a stair climbing wheelchair is to help people get up and down the stairs safely and avoid falls and fractures.

Remember that the stair-climbing wheelchairs that hurt patients were approved after testing them for safety and effectiveness.  It would make sense to make sure that future approval decisions require even BETTER research.

These devices are noted to be very heavy and are often used by people who are not able to get out of the wheelchair without help.  That obviously makes falls especially dangerous to both the users and their assistants.  For elderly patients especially, fractures can be serious or even life-threatening.

In addition to these safety issues, the battery charger can overheat and cause serious  burns.  That’s exactly what happened, in fact, which resulted in a moderate-risk recall 3 years ago.

If there were only 55 adverse events nationwide, that would not be so terrible.  But as has already been mentioned, reporting of adverse events is voluntary for physicians and consumers, and therefore the MAUDE system is not going to capture the vast majority of adverse events.  This is especially true of adverse events that will usually occur in the home, in the presence of family or caretakers who never heard of the MAUDE system.

Changing the classification from class III to class II means that companies who produce new models of stair-climbing wheelchairs will not have to demonstrate safety or effectiveness of their devices.  They will only have to show that their devices are substantially equivalent to other wheelchairs on the market.   But what if some of these stair-climbing wheelchairs that are on the market are safer than others?  We don’t have comparative effectiveness research to tell us if that is true, and so a company would be eligible for 510(k) clearance by showing the FDA that their new wheelchair is substantially equivalent to the worst wheelchair currently on the market.  By not requiring proof that the new wheelchair is itself safe and effective, we would be putting consumers in harm’s way.

In addition to lack of data on safety and efficacy, the lack of pre-market inspections means that nobody is checking to make sure that these wheelchairs are made the way they are supposed to be made, and that the batteries are safe and won’t cause burns.

Retaining Class III status and finally requiring proof of safety and efficacy will save lives, and certainly improve the quality of people’s lives.

Also under consideration today is whether mechanical wheelchairs should be reclassified from Class I (low risk) devices that require a 501(k) pre-market notification to a Class II with special controls (moderate risk) device that is exempt from 501(k) requirements.  This makes no sense at all – increasing the risk category but requiring less testing prior to marketing.

From 2006 to 2013, there were 3,492 adverse events reported in MAUDE with use of mechanical wheelchairs, including one fatality directly attributed to the device, and three other fatalities where the device cannot be ruled out as a direct cause of death.  Among these thousands of adverse events, there were 265 serious injuries.  The most common were fractures, fingertip amputations and cuts or lacerations.  During the same time period, there were also 12 recalls for problems such as premature bolt failure, improperly installed parts such as anti-tipper components and stabilizer bars, and inappropriate safety claims in advertising.

As part of the 1997 Food and Drug Modernization Act, FDA determined that Class I devices “that are of substantial importance in preventing impairment of human health, or any device that presents a potential unreasonable risk of illness of injury” must complete 510(k) pre-market notification requirements.  Based on the data presented here, how can anyone question whether mechanical wheelchairs present significant safety risks that substantiated that decision.

The central question regarding mechanical wheelchairs today is whether special controls will address these safety concerns if no 510(k) pre-market notification is required.  When people’s health and safety is at stake, as it clearly is here, the FDA should not lower the standards – especially for wheelchairs that don’t have a good track record to begin with.

Why make it even easier for poorly designed or badly manufactured wheelchairs to get on the market?  The 510(k) process is quick and easy – 90% of all 510(k) reviews result in approval, and many are cleared within only 2 months of their application!

For these reasons, the FDA should continue to require a 510(k) review for mechanical wheelchairs and also ensure that special controls are performed, both for mechanical wheelchairs currently on the market and new models in the future.