Perceptions of hyperbaric oxygen therapy among podiatrists practicing in high‐risk foot clinics

Abstract

Foot ulceration is a devastating and costly consequence of diabetes. Hyperbaric oxygen therapy is recognised as an adjunctive therapy to treat diabetes‐related foot ulceration, yet uptake is low. Semi‐structured interviews were conducted with 16 podiatrists who manage patients with foot ulcers related to diabetes to explore their perceptions of, and the barriers/facilitators to, referral for hyperbaric oxygen.

Podiatrists cited logistical issues such as location of facilities as well as poor communication pathways, lack of delegation and lack of follow up when patients presented for hyperbaric treatment. In general, podiatrists had an understanding of the premise of hyperbaric oxygen therapy and evidence to support its use but could only provide very limited citations of key papers and guidelines to support their position. Podiatrists stated that they felt a patient was lost from their care when referred for hyperbaric oxygen and that aftercare might not be adequate.

Improved referral and delegation pathways for patients presenting for hyperbaric oxygen, as well as the provision of easily accessible evidence to support this therapy, could help to increase podiatrists’ confidence in deciding whether or not to recommend their patients for hyperbaric oxygen therapy.

1. INTRODUCTION

Diabetes‐related foot ulceration (DRFU) is a debilitating condition, which frequently results in amputation and is estimated to affect up to 25% of those with diabetes mellitus.1, 2, 3, 4 Of the US$116 billion allocated for diabetes care in the United States in 2007, one‐third was used to treat DRFU.5 In Australia, there has been a 30% rise in lower limb amputation rates in the past decade6, 7; therefore, it is imperative that strategies to improve ulceration management are evaluated and put into place.

Hyperbaric oxygen therapy (HBOT) is the therapeutic administration of 100% oxygen at environmental pressures greater than 1 atmosphere absolute (ATA) to promote microvascular angiogenesis.8 The mechanisms by which HBOT works are still not fully understood, but HBOT has been shown to lead to the synthesis of growth factors and promotion of wound healing through the elevation of both the partial and hydrostatic pressure of inspired oxygen.9 In Australia, Medicare “funds” HBOT for longstanding and recurrent DRFU under the Medicare Benefits Schedule item number 13020. The National Health and Medical Research Council (NHMRC) endorsed the Australian Guideline on Prevention, Identification and Management of Foot Complications in Diabetes, which grades HBOT as Level B evidence,10 yet consensus amongst those who treat DRFU is that rates of uptake of HBOT are low. The medical director of Hyperbaric Health, Australia's largest private provider of HBOT (personal communication), estimated that the rate of referral to HBOT for DRFU represents less than 0.5% of the estimated 27 000 people treated as inpatients for this condition.11

In a previous qualitative study, patients who received HBOT found their treatment to be a positive experience.12 However, to date, no studies have investigated the perceptions of those who may be in a position to recommend and, therefore, influence the rate of referral to HBOT. In Australia, most DRFU are managed by multidisciplinary high‐risk foot clinics, which are predominantly staffed by podiatrists, as recommended by the NHMRC. The aim of the present study was to determine how podiatrists employed at public hospital high‐risk foot clinics understand, perceive, and evaluate HBOT as a treatment for DRFU. Barriers and facilitators that may result in HBOT being endorsed or rejected by those who influence management planning for patients with DRFU will be explored. The information yielded will be useful in the planning of health services for those with DRFU.

2. METHODS

2.1. Study design and population

A qualitative study consisting of in‐depth semi‐structured interviews of 15 to 30 minutes were conducted between August and November 2016. Recruitment for the study was initially from the heads of High Risk Foot Services within 100 km radius of Sydney, approximately 12 people. A snowball approach was taken whereby each of these individuals was invited to participate themselves and nominate another qualified podiatrist to partake in an interview (n = 16). Written consent was obtained from all participants included in the study. From the heads of service approached, 3 were not contactable, and 5 were unable to schedule a time for an interview; 4 were interviewed, and 12 other staff members were nominated for an interview. Of these, 9 were senior staff members (Level 3 or above as deemed by NSW Health), and 3 were junior staff members (Level 1 or 2 as determined by NSW Health). The levels of education in podiatry or related fields and clinical experience of the interviewees are summarised in Table 1. The study population comprised 8 males and 8 females with an average of 8 years of service in a high‐risk foot clinic (range 6 months to 18 years). The sample size was guided by the principle of saturation of the main themes—that is, recruitment continued until additional interviews were uncovering the same main themes as in previous interviews.

Table 1.

Characteristics of the interview participants; bachelor's degree (Undergraduate academic degree (3 or 4 years duration)

Participant	Position	Education level	Experience (years) in high‐risk foot (HRF) podiatry
1	Manager	Bachelor's degree, master's degree	10‐15
2	Senior Podiatrist	Bachelor's degree	5‐10
3	Junior Podiatrist	Combined bachelor's/master's degree	5‐10
4	Manager	Bachelor's degree, master's degree	15‐20
5	Junior Podiatrist	Bachelor's degree	1‐3
6	Junior Podiatrist	Combined bachelor's/master's degree	1‐3
7	Senior Podiatrist	Bachelor's degree	4‐5
8	Senior Podiatrist	Bachelor's degree	5‐10
9	Senior Podiatrist	2 X Bachelor's degree with honours	10‐15
10	Manager	Diploma	15‐20
11	Senior Podiatrist	Bachelor's degree	1‐3
12	Manager	Bachelor's degree, master's degree	5‐10
13	Senior Podiatrist	Unknown	5‐10
14	Senior Podiatrist	Bachelor's degree, master's degree	4‐5
15	Senior Podiatrist	10‐15
16	Senior Podiatrist	Diploma	15‐20

2.2. Interview guide

Interviews were informed by a schedule using open‐ended questions, shown in Table 2, which explored the following topics: knowledge, beliefs, and experience of HBOT; facilitators and barriers to recommending referral; previous interaction and experience with patients with regards to HBOT; and evidence‐based practice in general in podiatry.

Table 2.

Interview script

1. I just want to start off with you telling me about your understanding of hyperbaric oxygen and anything that may have encouraged you or stopped you from recommending hyperbaric oxygen to your patients. Prompts:

How effective do you think hyperbaric oxygen is?

How do you think it is supposed to work?

What would encourage you to or prevent you from recommending hyperbaric oxygen to your patients? (evidence of efficacy, rebate, previous experience, cost, availability)

2. If you have been asked by a patient about hyperbaric oxygen for people with diabetic foot ulcers:

What did you say to them?

Where did you obtain your information to inform your opinion?—prompt—patients, colleagues, clinicians, journals, conferences—what prompted you to choose these sources?

How did these resources influence your opinion of hyperbaric oxygen as a wound therapy?

Describe the current evidence base for hyperbaric oxygen for wounds as you see it.

What challenges are associated with using evidence‐based practice in your clinical decision making?

How can evidence‐based practice be better supported in your clinical role?

What experiences have you had or heard about in the past that may have influenced your opinion of hyperbaric oxygen?

3. Final questions:

How do you feel about recommending HBOT in the future?

What could be done to make you change your mind?

What do you think could be done to improve care for people with diabetic foot ulcers?

Is there anything you would like to ask me?

Interviews were conducted by a research assistant educated in podiatry (undergraduate degree with honours) at a quiet and convenient location at the participant's work place. Interviews were audio‐recorded and transcribed verbatim. All identifying information was removed, and pseudonyms were used throughout. Transcripts were analysed by thematic (inductive) analysis.13 From the data collected, repeated ideas, concepts, or elements were tagged as codes. As more data were collected from the transcripts, merging themes and associations between the codes led to the development of several categories. The principle of saturation informed the analysis, and data were collected until no new main themes emerged, that is, new interviewees no longer contributed to a deeper understanding of the themes. A proportion (20%) of transcripts were coded by an independent researcher and checked for agreement. Discrepancies were discussed, and adjustments to the coding framework were made as required once agreement was met.

2.3. Ethical considerations

The study was approved by the Human Research Ethics Committee of Western Sydney University (H11392) in compliance with recognised international standards, including the principles of the Declaration of Helsinki, and was carried out with the informed consent of participants.

3. RESULTS

All but 1 of the podiatrists who were interviewed were aware of hyperbaric oxygen as a therapy for the treatment of foot ulcers in diabetes and at least a rudimentary understanding of its mechanism of action. Overall, interviewees contended that the financial cost outweighed the benefit of the therapy. Participants also felt that the evidence available to support the use of HBOT for DRFU was extremely limited and would only recommend a referral at the patients’ request. Many of the participants expressed that they felt that their input to the patients’ care plan would be overlooked and their DRFU patients would be “lost” in terms of follow‐up and secondary preventative care (such as pressure‐offloading footwear) if they were referred for HBOT. Almost all participants felt that they had adequate systems in place for their continual professional development (CPD); however, they did not prioritise HBOT as part of their CPD.

3.1. Evidence base for HBOT as a treatment for foot ulcers in diabetes

Of 16 participants, 2 were very well informed about HBOT for DRFU and demonstrated that they had critically appraised current evidence. One of these patients was a service manager and extremely experienced podiatrist, whilst the other was, interestingly, a junior staff member who has a keen interest in evidence‐based practice and is also a lecturer in this subject area at the undergraduate level. They both reported awareness of guidelines regarding HBOT, mentioning the NHMRC10 and the International Working Group on the Diabetic Foot (IWGDF).14 Although both articulated that the guidelines mentioned HBOT, neither participant mentioned that the guidelines explicitly recommended the therapy for DRFU.

“The NHMRC guidelines certainly have a portion of it, just saying it exists, but they don't recommend it as a standard of care. That's replicated in the International Working Group as well.” (Manager)

“I don't think that we have enough evidence for or against it.”

(Junior Podiatrist)

One participant reported that he or she did not have any knowledge regarding HBOT and knew nothing of the indications for its use, process, or benefits—this person had less than 1 years’ experience managing a high‐risk foot.

The remaining 13 participants had limited awareness of research articles regarding HBOT. Of these participants, many reported that the evidence was “poor”, stating that the quantity and quality of evidence was very low and methodologically flawed, but they were unable to cite key publications to support this. Whilst a lack of robust methodology was frequently highlighted, participants did not provide specific examples of how bias or study design had informed their opinion, despite being prompted by the interviewer, per the interview schedule (Table 1).

“if there was evidence to back it up that it did greatly affect wound healing, then it would definitely be something we would advocate.” (Senior Podiatrist)

3.2. Hyperbaric therapy—mechanism of action

The 2 participants who had an in‐depth knowledge of the evidence base for HBOT also had a deep understanding of the theories related to its mechanism of action.

“my understanding is that the concept is obviously breathing pure or concentrated oxygen under pressure for a prescribed period of time, to try and improve oxygen saturation of peripheral tissues.” (Manager)

“I only read recently I think it's two to 2.5 atmospheres absolute or within that range. I think the absolute maximum is 2.8 for the chamber, so it's pressurised but also then saturated 100 per cent saturation of oxygen.” (Junior Podiatrist)

In general, the other participants had a basic knowledge of the mechanism of HBOT. Whilst they understood that HBOT increased oxygen saturation to a wound, they were unable to articulate exactly how this occurred and what effects this purportedly had on wound healing.

“From my understanding it is meant to improve the oxygen flow to the site which is important because in diabetes that's one thing that can be compromised, is the blood flow and the amount of oxygen getting to it, because without oxygen you can't heal it.” (Senior Podiatrist)

3.3. Recommendation for referral to hyperbaric therapy

Some participants outlined that they felt they could not recommend HBOT as it is not endorsed as best practice in New South Wales, and they were unclear if benefits would arise from its use. Participants spoke favourably of “gold‐standard” treatments and recommendations, such as debridement, offloading, multidisciplinary care, and more frequent patient review times. General opinion was that current evidence was not sufficient to warrant adjunct therapies such as HBOT.

“I think my perspective on it though is that we're so aware of the national guidelines and the international guidelines for managing diabetic foot along with that cost effectiveness, I'm not just sure in my opinion that it (HBOT) is worth it.” (Manager)

There was a notion that podiatrists did not have any input in the referral process. Decisions regarding the management of patients with DRFU were made by other members of the treating Multidisciplinary Team, and ultimately, recommendation decisions rested with specialist consultants and medical officers, who had the ability to refer patients to HBOT via the Medicare MBS schedule.

“that's normally where they're referred by their medical officer so either (the) general practitioner or vascular surgeon, so I didn't really have a voice or an opinion in that.” (Manager)

Geographical location of hyperbaric facilities was cited by some interviewees as a barrier for recommendation of referral. In the greater Sydney area, there are only 2 HBOT facilities, which limit accessibility for those who do not live close by.

“A big thing because currently our Hyperbaric Oxygen facility is in [named a suburb of Sydney] which is probably about an hour from here and the frequency that they're required to go ‐ sorry frequency and duration.” (Senior Podiatrist)

Two participants reiterated that the logistics of getting to and from HBOT facilities poses a challenge for the patients involved.

“It's the getting there and the transport and around that is the problem.” (Senior Podiatrist)

“I had one (patient) that was considering doing it, but because of travel arrangements and not having accommodation and what have you, didn't actually go through with it.” (Senior Podiatrist)

Participants highlighted that undertaking a course of HBOT could be onerous for the patient, specifically mentioning the time taken from the patients’ day to complete the appointments as well as the frequency of visits.

“So, you have to actually be available for a long period of time. If that doesn't suit your lifestyle or your work commitments et cetera it's probably not a therapy that you'd go for.” (Junior Podiatrist)

“One of the main issues that I've got with patients with Hyperbaric is that there's a whole set of appointments that they have to go to.” (Senior Podiatrist)

On the other hand, 1 podiatrist spoke of some motivated individuals for whom time would not be a barrier to undertaking HBOT therapy but inferred that distance was.

“I think if it was offered locally I don't think time is as much of a barrier because I think a lot of these people are prepared to do whatever it takes to heal a wound.” (Manager)

3.4. Organisation of care received

Clinicians who have recommended patients for HBOT expressed that they had very little contact or correspondence with patients and/or facilities once HBOT treatment had been initiated. They feared that patients referred to the care of the HBOT facilities lose contact and continuity of care with their regular care providers.

“I feel as though the clinicians that work at those facilities don't engage the multidisciplinary routine which manages diabetics… I didn't like how they really didn't interact with other colleagues who are obviously engaged in managing those patients.” (Manager)

Some clinicians reported that they felt patients returning from a course of HBOT came back with ulcerations worse than when they were referred.

“a few of our patients have accessed hyperbaric oxygen therapy and it hasn't always necessarily ended in a good result or a positive result or it hasn't ended in wound healing.” (Senior Podiatrist)

3.5. Podiatrists continuing professional education

All but 3 of the participants reported that they were not up to date with current literature regarding HBOT because of time constraints due to clinical workload being a barrier.

“I haven't really touched base of any hyperbaric literature in the last few years at least. But I'm sure it's out there. I just am a busy man and I just don't go around looking for research all the time.” (Manager)

Although they did not specifically reference HBOT literature during the interview, the majority of participants felt that they had adequate procedures in place to cater for their continual professional development in the area of evidence‐based practice and understanding research literature.

“We've got time set aside for our own individual research” (Junior Podiatrist)

“I think we do a pretty good job at having evidence based practice because every fortnight we do journal club, so if there is something that we're a bit unsure about we go and research it and bring it back.” (Senior Podiatrist)

Some participants commented that direct contact with HBOT care facilities would be beneficial to inform their decision as to whether a patient would benefit from hyperbaric therapy.

"Maybe even just doing a day there [at a HBOT facility] just to see how it is with patients" (Junior Podiatrist)

4. DISCUSSION

In general, podiatrists had an understanding of the premise of HBOT and an overview of the evidence base for the therapy. Podiatrists expressed concerns around the cost of HBOT in terms of financial cost to the health system as well the time and travel costs for patients. Podiatrists cited issues such as referral pathways, poor communication including lack of delegation of care, and poor follow‐up when patients presented for HBOT.

Several interviewees stated that they felt a patient was lost from their care when they were referred to HBOT due to lack of communication with HBOT facilities. Additionally, podiatrists feared the lack of long‐term patient follow‐up after HBOT had ceased.

4.1. Podiatrists perspectives on professional education and knowledge of HBOT

This study highlights that podiatrists who work in high‐risk foot clinics felt they were receiving adequate CPD but acknowledged that they had not specifically sought out information regarding HBOT. All but 1 of the podiatrists interviewed had an awareness of HBOT as a therapy for the treatment of foot ulcers in diabetes and at least a rudimentary understanding of its mechanism of action, but only 2 participants showed a deep knowledge of the therapy. CPD activities undertaken varied from semi‐structured journal club‐type meetings to self‐directed learning but did not follow a formal programme of study. Podiatrists have a wide scope of practice. HBOT is 1 of a whole plethora of wound therapies, yet 1 of the few a podiatrist cannot instigate themselves. It is therefore plausible that podiatrists’ interest in this area has diminished due to restrictions that preclude podiatrist‐initiated HBOT referral. This is exacerbated by lack of engagement with podiatrists and high‐risk foot clinics by HBOT providers.

Overall, there was a consensus that the evidence for HBOT was scarce, and studies were flawed and lacked scientific rigour. This viewpoint is broadly aligned with the current literature, such as the findings from a Cochrane Review, which concluded that HBOT has a short‐term benefit in DRFU but that further research is needed.15 A recent systematic review by Stoekenbroek et al16 and several other studies17, 18, 19, 20 report that HBOT is no longer considered a “fringe” therapy and shows some efficacy in improving the healing of DRFU in patients with concomitant ischaemia. Again, these studies suggest that larger trials of higher quality are needed.16, 17, 18, 19, 20

Evidence for the therapy has been disseminated but is not reaching or not being used by podiatrists. Participants did not cite specific studies to support their opinions or refer to any of the more positive outcomes from the literature, such as the conclusion of the Cochrane review (which states that there is evidence for HBOT in the short term).15 Interviewees frequently referred to “gold‐standard” therapies such as debridement and offloading, yet the evidence for these, as graded by the NHMRC, is actually no greater than that for HBOT (Level B evidence—Body of evidence can be trusted to guide practice in most situations). Most respondents stated they had not formally appraised the literature regarding HBOT, suggesting that knowledge had been gained in a non‐formal manner (defined as learning without intention).21 No participant referred to the fact that the therapy has a Medicare rebate available, which in itself might imply some proven degree of utility of HBOT for DRFU.

4.2. Podiatrists perspectives on recommendation for referral

The primary contact for patients in the majority of high‐risk foot clinics at tertiary hospitals is a podiatrist, per NHMRC guideline recommendations.10 Most patients with foot ulcers are frequently seen by their treating team,22 where the opportunity to build a strong therapeutic relationship exists. Patients rely on their treating practitioner to provide them with the most up‐to‐date management options based on evidence.23

A few participants stated that they would only recommend a referral to HBOT if the patient broached the subject or insisted. The reason commonly cited for this was the lack of evidence available to support HBOT use in DRFU, as well as previous experience of patients of poorer outcomes following HBOT treatment. Health care practitioners are challenged to deliver evidence‐based care whilst respecting patients’ rights to make decisions.24 Patients largely rely on the expertise of their treating practitioner so that joint decisions can be made regarding their care.25 Five individuals said that if patients expressed an interest in HBOT, they would facilitate referral, indicating that podiatrists are able to influence the referral process in some cases, even though they cannot refer directly and are engaged in joint decision‐making. Evidence‐based practice (EBP) has become increasingly important in health care as a framework for clinical problem solving that allows practitioners to keep up to date with current best practice in their field.26 If practitioners had a deeper understanding of HBOT and its evidence base, they would be more likely to raise HBOT in care‐planning discussions with patients (whether in a positive or negative light).

Sydney has only 2 hyperbaric facilities that treat foot ulcers, and both are located within 10 km of the CBD, whereas high‐risk foot clinics are, by comparison, abundant in the Sydney metropolitan area, meaning these clinics are geographically more accessible. There was opinion amongst interviewees that even motivated patients would be prepared to devote the time to HBOT, but travel to therapy and thus distance from facilities could be seen as a barrier to access.

Transportation barriers are an important barrier to health care access, particularly for those with lower incomes. A course of HBOT can be intensive, extending to up to 40 weekly sessions, lasting between 30 minutes and 2 hours per session. A study conducted by Eton et al (2012)27 explored the effect that intense health care regimens have on those with chronic conditions. The authors suggested that patients find it difficult to adhere to strict lifestyle alterations to control the symptoms and development of chronic diseases. They highlight that the usual mode of action from clinicians is to increase treatments, which can prove to be counterproductive and that the “burden of treatment” may lower the patients’ quality of life.27 This is mirrored in the concerns of some of the participants relating to the time needed to undertake a course of HBOT when combined with pre‐existing routine medical consultations. The rate of comorbidities relating to diabetes is high, mostly consisting of cardiovascular complications. Considering this, the majority of DRFU patients will be regularly attending consults to manage the disease. It is important to consider the time already dedicated to medical consultations as well as work and family arrangements and how this will affect patients’ quality of life. HBOT is considered an adjunct therapy and is deemed inaccessible by many clinicians. It is therefore likely that they will focus on more convenient therapies available rather than adding to the “burden of treatment”.

4.3. Podiatrists perspectives on patient care, follow‐up, and delegation

A common theme amongst interviewees was that input to their patients’ management would become obsolete, and they would ‘lose’ patients once they were referred to HBOT. Frequent references were made to the lack of communication from hyperbaric facilities once a patient had been referred and that there was no clear delegation of care. Clinicians felt disempowered by this situation and expressed concerns about HBOT facilities’ ability to provide aftercare, such as provision of suitable footwear once HBOT treatment was completed. As a result, clinicians felt less inclined to recommend hyperbaric oxygen. Professional “silos” have been identified amongst health care providers as barriers to health care delivery, leading to fragmented care.28 In interviews with recipients of hyperbaric oxygen and their carers, Katarina et al29 found that contact with primary health care became less functional once a patient was receiving HBOT, reinforcing the notion of patients becoming “lost to hyperbaric” and by proxy “lost to follow‐up” at high‐risk foot services from which they were derived.

Evidence suggests that a well‐facilitated multidisciplinary team can find creative ways to remove some flow impediments by organising and delineating tasks and responsibilities in patient care.6 Failure to formalise a delegation may be a key reason why podiatrist‐led recommendation to hyperbaric medicine is low. The Podiatry Board of Australia defines delegation as “one practitioner asking another person or member of staff to provide care on behalf of the delegating practitioner while that practitioner retains overall responsibility for the care of the patient or client”, 30 and the instigation of such would perhaps facilitate recommendation for referral.

4.4. Strengths and limitations

This study is the first qualitative exploration of podiatrists’ perceptions of HBOT care. By utilising a qualitative approach, we have been able to explore in detail the reasons why HBOT is not currently being recommended as a treatment for foot ulceration from the perceptions of podiatrists across Sydney.

The use of semi‐structured interviews in this qualitative study allowed for an in‐depth understanding of the use of HBOT for DRFU care. The sample size was relatively small; however, the in‐depth qualitative nature of the interview questions allowed for saturation to be reached at a relatively early stage.

Podiatrists are not able to refer directly to HBOT; only medical practitioners have this right under the Medicare Benefits Schedule, and the interview was scripted to reflect that fact. Non‐referring participants were specifically asked whether they would recommend referral for HBOT as opposed to actually referring directly. Despite this, several respondents stated they ‘could not refer’ for HBOT, indicating that this question may have been misinterpreted based on its wording—podiatrists understood the term “recommendation” in this case to have the same meaning as “referral”.

Participants were recruited from a relatively small area of Sydney, and perceptions of HBOT may have been influenced by local factors such as experiences with local providers of HBOT, and perceptions may be different in other areas of Sydney, Australia, or other countries where health care systems are different. Participants were only recruited from public hospitals because most people with longstanding foot ulcers are managed by public hospital clinics. Whilst it is accepted that qualitative studies are not generalisable and that podiatrists not interviewed may have different opinions of HBOT based on their own experiences and their appraisal of the evidence, it is noted that analysed results are transferable to people and contexts with similar characteristics.31 Therefore, the themes explored can be viewed as a representation of current opinion within the field.

5. CONCLUSION

This present study reveals that poor communication, including lack of defined delegations and negotiated care planning from HBOT providers, are barriers to recommendation for referral.

A more collegial approach between high‐risk foot clinics and HBOT facilities, along with the synthesis of more robust evidence to support HBOT and current evidence being better translated into practice, would increase the likelihood that HBOT would be raised by podiatrists in care‐planning discussions with patients. This should be noted when planning health care services.

As a result of our analysis, we recommend that improved access to guidelines and publications could address practitioners’ limited knowledge of HBOT, and as a result, this could influence referrals for HBOT. Another strategy might be the more formalised and structured delivery of CPD from impartial providers, such as the Australian Podiatry Association, the peak body for podiatrists in Australia.

Henshaw FR, Brennan L, MacMillan F. Perceptions of hyperbaric oxygen therapy among podiatrists practicing in high‐risk foot clinics. Int Wound J. 2018;15:375–382. 10.1111/iwj.12874