Outcomes Measurements in Upper-Limb Prosthetics: Why So Elusive?

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The O&P EDGE assembled a panel of upper-extremity specialists to share their expertise and express their opinions on a variety of subjects relating to upper-limb prosthetics. Their responses are featured in a series of articles in print and online.

Our panel of experts:

Randall Alley, BSc, CP, FAAOP, is the head of Clinical Research and Business Development for the Hanger Prosthetics & Orthotics Upper Extremity Prosthetic Program. He is chair of the Upper-Limb Prosthetics Society of the American Academy of Orthotists and Prosthetists (AAOP) and an international lecturer and consultant.

Diane Atkins, OTR, A clinical assistant professor in Physical Medicine and Rehabilitation at the Baylor College of Medicine in Houston, Atkins is an occupational therapist who has specialized in amputee rehabilitation for more than 25 years-with special focus on rehabilitation of the upper-limb amputee.

John Billock, CPO/L, FAAOP, a past president of the Academy, is the clinical/executive director of the Orthotics & Prosthetics Rehabilitation Engineering Centre, Warren, Ohio.

Carl Brenner, CPO, is the director of Prosthetic Research at the Michigan Institute for Electronic Limb Development, Livonia, Michigan.

John M. Miguelez, CP, FAAOP, president of Advanced Arm Dynamics, serves as a clinical consultant worldwide on issues regarding upper-extremity prosthetics and operates a Center of Excellence in Dallas, Texas.

Robert H. Meier III, MD, is the founder of Amputee Services of America, a comprehensive "center of excellence" that addresses issues related to limb amputation. Meier's experience in rehabilitating persons with amputation encompasses some 2,700 amputees, 45 percent of whom are upper-limb amputees.

Question: Why, in your opinion, have accurate and acceptable outcomes measurements in upper-limb prosthetics been so elusive?

Alley: There are innumerable reasons for the lack of adequate outcomes in upper-extremity prosthetics. The problem lies in two distinct areas: the sheer scope and variety of variables surrounding and unique to each case, and the instruments used to gather the data.

Acceptable outcomes are elusive because many of the variables involved that are critical in determining patient acceptance of an upper-extremity prosthesis have little to do with the prosthetic device, and more to do with psychological and psychosocial adaptation to traumatic upper-limb loss, which is more common than congenital amelia or elective amputation.

So while the focus has been on comparing one type of prosthetic control to another, we need to look more closely at determining, for example, when presented with two patients with identical limb loss and matching prosthetic devices, why one was successful and the other was not. This is the crux of the issue.*

*Note: See Alley's in-depth discussion of the outcome measurements problem in OrthoKinetic Review, "Optimum Outcomes," April 2002.

Atkins: Outcomes measures for upper-extremity amputees are very difficult to define in clear objective terms. The score is prone to be very subjective-based upon (a) the experience of the evaluator-usually an occupational therapist, and (b) the knowledge of the evaluator of what is appropriate to ask the amputee to do with a prosthesis.

So many questions must first be answered: Is it more appropriate for the unilateral amputee to do an activity without the prosthesis and accomplish the activity with the good side? If the prosthesis is used to assist in dressing, for example, is the prosthesis helpful or a hindrance in terms of time and effort? Does the amputee need adaptations tor clothing to achieve independence? How do we account for extraneous body movements that may be used to accomplish an activity? What is an appropriate time factor to allow?

How can all these considerations be factored into a simple outcome measure?

Since the level of the amputation and the dominance or non-dominance of the limb involved will impact the scoring, should there be a different expected outcome measurement and score dependent upon (a) the level of limb loss, (b) whether the dominant or non-dominant limb was lost, and (c) whether the amputee is unilateral or bilateral?

Having a consistent evaluator at the initial stage of evaluation, mid-point and end of the evaluation should be kept in mind, as well.

These are just a few of the factors that play a large part in this equation. A good outcome measurement tool is definitely needed, but the ease with which it is designed and executed is the challenge.

Billock: Developing acceptable outcomes measurements is difficult in all areas of prosthetics. I think, however, that there is just not sufficient effort being made to pursue this particular problem. Speaking for myself as an independent facility owner, I find the requirements of managing a business in general day-to-day practice and serving patients challenging enough; there's not much spare time to get together with other prosthetists and try to evolve such a system, although one is certainly needed.

The complexities and shortcomings of today's reimbursement system are another such key issue-also not getting the attention it should.

Since there are smaller numbers of upper-limb patients, this is an area of prosthetics that receives less attention. Likewise, there is not as much focus on upper-limb prosthetics for that reason. In schools with prosthetic programs, there is less time is spent on teaching upper-limb prosthetics because of the lesser likelihood that students may someday have to fit an upper-limb patient.

Brenner: I think for the greater part, the failure to develop appropriate outcome measures is because the population we are dealing with is so small in terms of potential patients, and there are fewer upper-limb practitioners. We're also dealing with a low-utilization issue, as opposed to lower limbs where there is extremely high utilization. Major programs such as Medicare need to equate function with components.

However, upper-limb procedures are not driven in that way by third parties, simply because utilization isn't very high.

Miguelez: I think they've been elusive for a number of reasons.

1) There are probably three tiers of prosthetic experience in the United States-which apply to prosthetists, therapists, and doctors, as well: Those who see a lot of upper-limb amputees are in one tier; those who see perhaps two to five a year in another; and those who rarely see an upper limb amputee in the third tier.

Coming up with appropriate outcomes studies is difficult because not only are the practitioners' experience levels so diverse, but the outcomes are practitioner-related; you have a much greater potential for maximizing rehab potential if you go to a prosthetist who has more experience.

That group of experienced practitioners is very small and can be competitive, so sharing that information among themselves is something we haven't seen.

2) There are several outcomes measurement systems, but they are somewhat antiquated. They are based on a body-powered approach as the primary approach, then try to shoehorn in other prosthetic options. An appropriate outcome measurement needs to really look at all the options.

3) Such studies need to look not only at the time of therapy-within the first few days of fitting-but also a year after prosthetic intervention, when the patient has had time to fully adjust to his prosthesis. I can get someone functional within a few days, but if the patient is still using the prosthesis a year later, it means we have truly solved his issue, and the prosthesis has been integrated into his lifestyle. This is much more challenging than the question of whether he can open and close the terminal device or flex the elbow, or pick up X or Y.

4) There are several outcome measurement tools available, but we don't have one that covers everything. The question is, do we develop our own? That could solve our company's internal challenges; but then when you share your findings with other people, they're not using your system, so your data doesn't mean a lot.

If you use an existing system, you'll find that none of them have a really comprehensive approach that we can all agree upon.

I'd love to see such a system that offers the ability to influence patient decisions based on reproducible tests that could perhaps demonstrate that the experience of the rehab team does have a direct impact on the patient's ability to maximize rehab potential.

We've all discussed this-but coming up with a measurement tool specific to upper limb patient needs is a real challenge due to the personalities involved. When I was in charge of the NovaCare upper extremity program, there was a lot of discussion about this. I wouldn't say that this is a contentious situation, but if a company puts costly resources into the development of such a tool, it's difficult for them to share it freely-or it has been so far.

Meier: Outcomes measurements in upper-extremity prosthetics have been difficult to develop simply because no one has been willing to take the time, effort, and expense to do so. Compiling scientifically valid data takes time most people are not willing to spend.

The responsibility for coming up with a reliable measurement tool probably belongs in a center of excellence with an academic base. At one time, the old NovaCare organization was attempting to develop a system, but they were basing it on patient satisfaction, which is not the most proper criterion if data is to be valid and reliable. Patients may be satisfied with poor workmanship or function because they don't know the difference.

Judith Otto is a freelance writer based in Holly Springs, Mississippi.