A few weeks ago we published a manuscript about the development of the Wound Healing Index for Venous Leg Ulcers (VLUs). The link is below.

What is the VLU WHI?

The VLU WHI makes it possible to predict at the initial visit whether a venous ulcer will heal with standard wound care. The model incorporates both wound and patient factors. In other words, you do not have to wait 4 weeks to predict whether a wound will heal.

What is the VLU WHI Used For?

Medicare’s Quality Payment Program (QPP) is changing reimbursement from a system based only on volume to one based on outcome. Healing is a very obvious outcome for us to report to Medicare under the QPP. However, without some way to understand how sick the patients are and/or how bad the leg ulcers are, it is not possible to compare healing rates fairly between practitioners. Without a “risk stratification” or some type of “severity score,” the practitioners caring for the sickest patients will appear to have worse outcomes than their peers whose patients are not as difficult. Also, without risk stratification, it’s too tempting to assign all the sick patients to some “palliative” category out of fear that your healing rate will look bad, and then report >90% healing rates.

There are a lot of problems with “imaginary” healing rates, but the biggest one is that CMS does not allow outcomes to be reported that way. CMS requires that if an outcome is reported under the QPP, it MUST be risk stratified so that fair comparisons can be made from one practitioner to another. That’s why we spent years creating the WHI (in conjunction with the Institute for Clinical Outcomes Research at the University of Utah),  a series of 7 predictive models. (There are different models for different wound types.)

Since 2015, venous leg ulcer and diabetic foot ulcer healing rates have been reported to CMS using the WHI to stratify wound by their predicted likelihood of healing. Wound centers should not brag about healing wounds that were going to get well anyway! Additionally, practitioners should not be “punished” or subjected to an “intervention plan” if they are not able to heal wounds that are so severe we know they are highly unlikely to be healed.  (Sometimes we do heal the wounds we think are impossible, and when we do, it’s a BIG DEAL and might suggest the treatment(s) we used were highly effective. However, but you can’t celebrate that accomplishment without a way to stratify wounds by severity!)

The category that is the most interesting is the middle group – the wounds that might or might not heal – depending on what we do. If you want to find a terrific wound management practitioner, look for one with high healing rates in that middle category. Among the wounds that “could go either way,” quality of care is everything.

Right now, the primary use of the VLU WHI is in reporting venous leg ulcer healing rate to CMS under the Merit Based Incentive Payment System (MIPS).  (We also use the DFU WHI to report diabetic foot ulcer healing rate, and new in 2019 we will use the PrU WHI to report pressure ulcer healing rates). However, the WHI is also used to create matched cohorts of real world patients for retrospective comparative effectiveness studies, and occasionally to help match cohorts for prospective randomized trials of VLU treatments.

The take-home message about the WHI is that if a quality action (e.g. adequate compression) or a TREATMENT really make a difference, then we will see healing among VLUs predicted to fail. This means that the VLU WHI can demonstrate when, for example, venous ablation or a CTP made a difference (and thus was worth the COST!). That seems like a powerful tool to have, but not everyone is happy about it. . . .

Model predictions will be available for incorporation into any electronic health record via “SMART app” technology in a few months. I will keep you posted on that.

Check out the abstract here:


The 90% development model included 9,898 ulcers, of which 7,498 healed (75.8%). The 10% validation sample included 1,044 ulcers, of which 809 healed (77.5%). The following variables significantly predicted healing in VLUs: number of concurrent wounds of any etiology, wound size, wound age (in days), evidence of bioburden/infection, the patient is non-ambulatory, and the patient underwent hospitalization for any reason.

Conclusions: The WHI can identify which VLUs most likely require adjunctive therapies to heal, prioritize referral to venous experts, risk-stratify ulcers to create more generalizable clinical trials and understand the impact of clinical interventions. The Centers for Medicare and Medicaid Services accepts this method for reporting VLU outcome under the Quality Payment Program.

For fun, answer these two questions:

1. The majority of venous ulcers enrolled in the prospective trials of cellular and/or tissue based products (CTPs) generally fall into which of the following categories:

A. VLUs that could be predicted to fail with standard treatment
B. VLUs that are about equally likely to heal or not heal
C. VLUs that could be predicted to heal with standard wound care

Answer: C

The majority of VLUs enrolled in prospective trials of CTPs could have been predicted to heal without the use of a CTP, if the trials ran long enough.

2. The majority of venous ulcers actually TREATED with cellular and/or tissue based products (CTPs) fall into which of the following categories:

A. VLUs that could be predicted to fail with standard treatment
B. VLUs about equally likely to heal or not heal with standard treatment
C. VLUs that could be predicted to heal with standard wound care

Answer: Categories A and B

The majority of VLUs TREATED with CTPs (at least in hospital based outpatient wound centers) were not likely to heal with standard care alone, because the patients were so sick and/or the total wound surface area was very large. The VLUs we treat clinically are totally different from the ones we enroll in most clinical trials, and that is very sad.