Provider Strategy

Clinically Speaking: Group 2 vs. Group 3

Determining which type of power wheelchair is right for a client requires 'knowing the code' as well as understanding patient needs.

Selecting the clinically appropriate power wheelchair (PWC) base for an individual with a permanent need for mobility assistive equipment can be daunting, even for the most experienced clinicians. With 29 power wheelchairs showing as “active” on the Pricing, Data Analysis and Coding (PDAC) website in the Group 1 category, 366 available in the Group 2 category, 297 in the Group 3 category and 66 listed in the Group 4 category how does anyone narrow down the selection to the “right one?” The reality is, there are not 758 power wheelchairs that can meet the unique identified needs of an individual, there are a much smaller number once you “know the code.”

On Nov. 15, 2006 the Centers for Medicare and Medicaid Services (CMS) established new HCPCS codes for all powered mobility devices based on their specific features, functions and minimum performance criteria. In advance of this change CMS sought advice from a Technical Expert Panel (TEP) comprised of industry leading engineers, technicians, specialists, corporate officers, and advocates in the development of the codes and testing standards to differentiate each category of chairs.

Connecting Devices to Need

We can use this information, derived from subject matter experts, to help narrow down the selection process. For adult power wheelchairs the TEP recommended four power wheelchair categories, based on speed, range and terrain handling features so the first question is, what group will accommodate my patient’s daily routine in all settings of anticipated use?

1. Standard Use (Group 1) – A category of chairs designed primarily for intermittent use on flat, hard surfaces with minimal surface irregularity.

2. Standard Plus Use (Group 2) – A category of chairs designed primarily for regular use on flat hard surfaces with minimal to moderate surface irregularity.

3. General Use (Group 3) – A category of chairs designed for a mixture of continuous use on flat to rolling terrain, and hard surfaces with moderate surface irregularity.

4. High Activity Use (Group 4) – A category of chairs designed for frequent use on uneven terrain, hard and soft surfaces with moderate to extreme surface irregularity, or for speeds and ranges that exceed those of chairs designed for standard or general use.

Group 1 PWCs are ideally suited for beneficiary’s living in an independent or assisted living facility due to their limited performance characteristics. On the other end of the spectrum, CMS determined that Group 4 PWCs have performance characteristics that are not necessary for use in the home and will not consider them for coverage and reimbursement. However, many other third-party payers may provide funding for this level of PWC for the health, safety and well-being of the individual, especially when it allows them to live in the “least restrictive environment possible” (i.e., home and community).

Defining “Use”

This leaves us with Group 2 and Group 3, which takes us down to 663 PWCs. The second question is, what is the difference between “regular use” and continuous use?” In its local coverage determination (LCD) for powered mobility devices CMS implemented restrictions for reimbursement purposes between these two groups of PWCs, which we can use as a guideline when recommending the right power wheelchair base, but it is just that — a guide. Per the LCD and individual must have a neurological condition, a myopathy or a congenital skeletal deformity to qualify for a Group 3 PWC.

Typically, individuals that fall into one of these three diagnostic categories will, in fact, use their chair all day, every day as their only way of moving about for the 12 to 18 hours they are up out of bed. However, there are many other individuals that do not have a diagnosis that fits in one of these categories such as, but not limited to rheumatoid arthritis, multiple limb amputations, etc. who may also use their PWC on a continuous basis as opposed to bouts of use.

Assisted vs. Unassisted Transfers

This brings us to our third question: can the individual transfer to and from the PWC independently and change their position in it of their own volition, or do they require assistance to transfer and the mechanical means to change their position in the chair throughout the day?
For individuals who must change their position by mechanical means the TEP recommended that power seat functions only be available on power wheelchair bases designed for “continuous or high activity use” as follows:

1. Specific Use (Single Power Option) – A category of chairs designed for a mixture of indoor and outdoor use on flat to rolling terrain, and hard surfaces with moderate surface irregularity and with the capability to accommodate positioning and power modalities and accept one power option at a time on the base.

2. Specialized Use (Multiple Power Options) – A category of chairs designed for a mixture of indoor and outdoor use on flat to rolling terrain, and hard surfaces with moderate surface irregularity and with the capability to accommodate positioning and power modalities and accept more than one power option at a time on the base.

As we know, CMS did not take this advice from the TEP and included HCPCS codes for Group 2 PWCs with single and multiple power options in the code set. However, when we analyze the Medicare provision of single and multiple power option chairs from 2010 to 2017 we find that 86.5 percent of them were provided on a Group 3 base. Why is this the case when roughly 95 percent of the PWCs with no power options provided during that timeframe were coded in the Group 2 category? Is it because the clinical and provider community is unaware that there are Group 2 power wheelchairs with a power tilt option available? Is it because two of every three where a medical need for power seating is established include both power tilt and recline for a multitude of reasons, and there are no Group 2 PWCs with a combination power tilt/recline available in the United States? Or, Is it because clinicians and providers are intuitively following the recommendations put forth by the TEP?

Clinically speaking, the vast majority of individuals with a permanent need for a power wheelchair that use it continuously for 12 to 18 hours per day and have a medical need for power tilt, power recline or the combination of power tilt and recline require the performance characteristics of the Group 3 base, regardless of diagnosis, to safely navigate all settings of actual and anticipated use. The difference between the two groups is as follows:

All Group 2 PWCs must meet the following requirements:

  • Minimum Top End Speed – 3 mph
  • Minimum Range – 7 miles
  • Minimum Obstacle Climb – 40 mm (slightly more than 1 1/2 in.)
  • Dynamic Stability Incline – 6 degrees

All Group 3 PWCs must meet the following requirements:

  • Minimum Top End Speed – 4.5 mph
  • Minimum Range – 12 miles
  • Minimum Obstacle Climb – 60 mm (about 2 3/8 in.)
  • Dynamic Stability Incline – 7.5 degrees
  • Drive wheel suspension to reduce vibration

Minimum top end speed is important as it is used in bouts: 3 mph is roughly the average walking speed of adults while 4.5 mph is a brisk walk, much like ambulatory individuals use when crossing the street. It is not needed all the time, but when it is needed it is essential to have.

For an individual that will use their chair continuously the distance per charge is extremely important, especially if they are traversing a multitude of terrains, are closer to the top end of the chair’s weight capacity, must cover long distances or a combination of all three, which draws a lot more power from the batteries. For anyone that wears an activity tracker you know that there are days when you barely get 10,000 steps in, but then there are days when you walk 10-plus miles because of the activities you are engaged in. Wheelchair users need the same capability.

If the individual traverses mostly level terrain, and the environments they encounter consist of minimal transitions a Group 2 base that can navigate a 1 1/2 in. threshold may meet their needs. However, if the environment they will, or are likely to encounter once they are provided with an appropriately configured PWC includes uneven concrete, grass, gravel etc. then a Group 3 chair that can safely navigate a minimum obstacle height of 2 3/8 in, would be necessary for safe navigation.

A ramp that is compliant with the American’s with Disabilities Act (ADA) has a slope of 4.8 degrees. If the individual has absent or impaired sensation or balance limitations, the ability to safely negotiate a 7.5 degree incline (whether that be a ramp or the landscape of mother earth) is essential for safety. Someone with an impaired sensory-motor feedback system will likely be unable to sense a Group 2 base tipping, which puts them at risk for injury when they encounter a hill or steep ramp.

Lastly, any PWC user in the chair for extended periods of time should have a drive wheel suspension system, as required for code verification as a Group 3 chair, because the constant jarring forces placed on the body can be extremely destructive over time. In addition, drive wheel suspension may be necessary to reduce spasticity or reflex activity, increase postural stability and allow the user to maintain contact with the drive control device.

When recommending “the right wheelchair” for a consumer that will be using it continuously throughout the day, every day in a variety of settings it is important to keep this very important information in mind.

This article originally appeared in the Jan/Feb 2019 issue of HME Business.

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