Hi Amanda, thanks for your question. Interesting topic for your DNP project! Wondering if the project focuses on patients seen at a national, regional or institutional level. Also, I'm assuming the patients you are referring to are patients seen at wound clinics, and not at other types of clinics? Dr Worth and I briefly discussed your question today, and here are some of our thoughts: 

1) Regarding the barrier you mentioned to obtaining ABI upon first visit  ("the MD's prefer to do US instead"): wondering if this observation was based on data from an institutional sample? Meaning, do MDs from a specific institution(s) you studied prefer to order US instead of ABI? Also, by 'US', assuming it's referring to arterial duplex ultrasound (DUS)? 

2) Regarding your question "are there any resources you know of that revert back to the least invasive ABI before waiting for US?"
It'd be important to understand the reasons why the providers are preferring to order arterial DUS instead of ABI or other noninvasive arterial testing. Would it be because providers are not aware of recommendations by clinical guidelines? Or because there are administrative obstacles or lack of available resources that prevent timely delivery of ABI results? Or maybe there are some other motivations/obstacles? (e.g. maybe providers were not happy with ABIs done in the past?)
Below are some resources that could be helpful in reverting back to ABI and other less costly noninvasive arterial tests before DUS: 
* Clinical evidence: 
-For all patients with suspected CLTI/PAD, clinical guidelines recommend ankle brachial index (ABI) and ankle pressure (AP) and as the first-line screening tests to detect PAD. However, limitations include falsely elevated readings in patients with non-compressible arteries due to arterial calcification, often seen in patients with diabetes, renal insufficiency or advanced age. For patients with advanced age, diabetes mellitus, chronic kidney disease, or ABI > 1.3, guidelines recommend measuring toe pressure (TP) and toe brachial index (TBI) to screen for PAD. (Guidelines: Society for Vascular Surgery and European Society for Vascular Surgery, WOCN, WHS, IWGDF) There is no mention of DUS as a screening test.
-Once ischemia in the wound bed is identified, prior to referring a patient to vascular specialist, wound clinicians may wish to consider ordering an arterial DUS to help expedite decisions about revascularization. DUS provides information on the anatomic location and extent of arterial disease as well as information about flow volume and velocity. However, DUS is time-consuming and highly operator dependent.
-DUS is indicated for patients with vascular symptoms (Claudication  • Ischemic rest pain  • Arterial ulceration  • Peripheral arterial disease (PAD)  • Suspected arterial  embolization  • Follow-up endovascular procedure (e.g., angioplasty, stent)  • Bypass graft  • Pseudo-aneurysm  • Arterio-venous fistula  • Hemodialysis access  • Trauma), and not for PAD screening. See Society for Vascular Ultrasound Guidelines
See:
 https://woundreference.com/app/topic?id=arterial_ulcers_intro_assessment#-noninvasive-arterial-tests,
 https://woundreference.com/app/topic?id=arterial_ulcers_intro_assessment#-vascular-imaging 
https://woundreference.com/files/13496.pdf
https://www.svu.org/practice-resources/professional-performance-guidelines/
https://woundreference.com/files/14262.pdf

* Cost effectiveness:
If at risk patients are asymptomatic, screening for PAD with ABI would be cost-effective [1].
For patients with DFU, studies show that TBIs or SPPs used uniformly or to corroborate a normal pulse examination finding are among the most sensitive and cost-effective strategies to improve the identification of PAD  [2]
[1] https://pubmed.ncbi.nlm.nih.gov/24476213/
[2] https://pubmed.ncbi.nlm.nih.gov/27575813/

* Reimbursement: 
Not sure if having in-office vascular testing is even an option, but the clinic could invest in an in-office vascular testing device that allows on-site billable ABI. This could generate a good return on investment while providing outstanding care for at-risk patients, provided LCD requirements are met. Staff performing the test would need to become certified. While vascular testing for screening purposes is not reimbursable, most LCDs dictate that if patient has "vascular symptoms" (pain at rest, foot ulcer, gangrene, claudication, etc), provider can bill for the vascular test. CPT 93922 (Limited bilateral noninvasive physiologic studies of upper or lower extremity arteries, (eg, for lower extremity: ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus bidirectional, Doppler waveform recording and analysis at 1-2 levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries plus volume plethysmography at 1-2 levels, or ankle/brachial indices at distal posterior tibial and anterior tibial/dorsalis pedis arteries with, transcutaneous oxygen tension measurement at 1-2 levels)
See:https://www.podiatrytoday.com/ancillary-modalities-office-what-are-best-investments
LCD in Florida: https://www.cms.gov/medicare-coverage-database/details/lcd-details.aspx?LCDId=35761&ver=34&articleid=57593&keyword=Non-Invasive+Vascular+Studies&keywordType=starts&areaId=s12&docType=NCA%2cCAL%2cNCD%2cMEDCAC%2cTA%2cMCD%2c6%2c3%2c5%2c1%2cF%2cP&contractOption=all&sortBy=relevance&KeyWordLookUp=Doc&KeyWordSearchType=Exact&bc=AAAAAAQAEAAA&

* Patient cost: 
DUS is 3x more expensive than an ABI (93922 Upper/lower extremity physiologic studies (ABI/DBI) 2020 global charge is $155.00 vs. $455 for 93925 Lower extremity arteries/arterial bypass grafts duplex – bilateral)

* CMS Quality Measure/ Physician Compare site: 
The U.S. Wound Registry, which develops Quality Measures that wound clinicians can report when participating at CMS Quality Payment Program (MIPS), developed a reportable measure called "Non-Invasive Arterial Assessment of patients with lower extremity wounds or ulcers for determination of healing potential". Definition of arterial vascular evaluation: measurement of the ankle-brachial index, skin perfusion pressure measurements, transcutaneous oximetry, toe pressures or arterial Doppler studies. DUS is NOT included here. The arterial screening quality measure was chosen by CMS to be depicted on the Physician Compare website in 2019. 
https://www.todayswoundclinic.com/articles/vascular-assessment-enters-21st-century

3) one more thought, regarding "percentage of patients having ABI done on first visit": since ABI is not the best test for patients with diabetes, advanced age, chronic kidney disease etc, in addition to the percentage of patients having ABI done upon first visit, maybe it might be interesting considering how often other noninvasive tests are done (TCOM, SPP, TP, TBI or handheld audible Doppler with waveform) as well? Maybe you have already seen it, but the US Wound Registry reports that fewer than 10% of patients with chronic non-healing leg ulcers undergo any type of vascular assessment (ABI, transcutaneous oximetry or skin perfusion pressure) even at hospital based outpatient wound centers.

Hope this helps!

Wow, thank you very much for all of your thoughts and time! I am glad to know that some of this information I have come across in my research such as guidelines and CMS. I was just so confused as to why the MD's revert to ordering US.

The project setting is an outpatient wound care clinic with HBOT and ability to bedside ABI via manual and automatic device. The MD's prefer manual bedside ABI because they feel the matching is not accurate. One of their reasons for ordering US. And, I had the same thoughts as you and your colleague did, as far as cost and availability. It is quicker and non invasive and less expansive as you also mentioned above, so I just could not understand why they would jump to the test, "because it gives better results."

National barriers that I have read in my research include time constraints, lack of providers and nurses (that are trained), and ulcer location, just to name a few. The director of the clinic has done recent education once again with the staff, and increased staff in the clinic to help with patient load. But, is seems that ABI take more than 30mins than the estimated, "15mins" that guidelines state, and they lack staff and room to do so (another barrier). Obviously, for this project I have to narrow it down to one thing.

There is a compliance issues with ordering ABI, and I do agree I would love to study the TBI etc (because they are more accurate), but at least with the first test, it can lead to further testing, but something is being done on the first visit. Guidelines state, "Every patient should have a ABI and foot assessment in wound clinic.:

I plan to do a retrospective chart review over a 6 week period on what percentage of patients had ABI done on first visit. I will use a template to track compliance in the clinic with every new patient where the provider will be able to check a box when the test was ordered and why it wasn't (providing a brief summary). I will provide education on current guidelines before implementation of template, and then measure the data over 6 weeks.

Thank you so much for providing information on the cost! That was going to be the next information I was going to research! I have to present to my hospital IRB, and that information will be extremely helpful. Thank you so much!

Implementing this project, I see so much I would love to research! The hard part is narrowing it down to a workable 6 weeks! :)

Wow, thank you very much for all of your thoughts and time! I am glad to know that some of this information I have come across in my research such as guidelines and CMS. I was just so confused as to why the MD's revert to ordering US.

The project setting is an outpatient wound care clinic with HBOT and ability to bedside ABI via manual and automatic device. The MD's prefer manual bedside ABI because they feel the matching is not accurate. One of their reasons for ordering US. And, I had the same thoughts as you and your colleague did, as far as cost and availability. It is quicker and non invasive and less expansive as you also mentioned above, so I just could not understand why they would jump to the test, "because it gives better results."

National barriers that I have read in my research include time constraints, lack of providers and nurses (that are trained), and ulcer location, just to name a few. The director of the clinic has done recent education once again with the staff, and increased staff in the clinic to help with patient load. But, is seems that ABI take more than 30mins than the estimated, "15mins" that guidelines state, and they lack staff and room to do so (another barrier). Obviously, for this project I have to narrow it down to one thing.

There is a compliance issues with ordering ABI, and I do agree I would love to study the TBI etc (because they are more accurate), but at least with the first test, it can lead to further testing, but something is being done on the first visit. Guidelines state, "Every patient should have a ABI and foot assessment in wound clinic.:

I plan to do a retrospective chart review over a 6 week period on what percentage of patients had ABI done on first visit. I will use a template to track compliance in the clinic with every new patient where the provider will be able to check a box when the test was ordered and why it wasn't (providing a brief summary). I will provide education on current guidelines before implementation of template, and then measure the data over 6 weeks.

Thank you so much for providing information on the cost! That was going to be the next information I was going to research! I have to present to my hospital IRB, and that information will be extremely helpful. Thank you so much!

Implementing this project, I see so much I would love to research! The hard part is narrowing it down to a workable 6 weeks! :)