Diabetic Foot Australia guideline on footwear for people with diabetes

The Diabetic Foot Australia guideline on footwear for people with diabetes aims to provide guidance to the multidisciplinary healthcare professionals involved in the provision of footwear for people with diabetes. The Australian Diabetes Foot Network 2013 practical guideline on the provision of footwear [16] was used as a baseline for the creation of this updated guideline. Information from the 2013 footwear guideline was updated first by the primary author after reviewing and incorporating any new footwear-related recommendations from the most recent Australian National Health and Medical Research Council (NHMRC) diabetic foot guideline [31] and the International Working Group on the Diabetic Foot (IWGDF) guidance documents [10, 14, 15]. The primary author then reviewed and incorporated common findings from all recent systematic reviews on footwear interventions for people with diabetes [17‐22], recent randomized controlled trials included in these reviews [23, 24], and finally any further studies obtained from hand searching reference lists of these articles and an additional non-systematic search of the literature [9, 25‐30]. After collating all findings, three tables and one figure were created describing footwear requirements and offloading effects of footwear modifications to prevent diabetic foot ulceration, based on published literature [10, 15, 16, 32‐34] and expert opinion. Furthermore, to ensure a common and clear vocabulary between all the different multidisciplinary healthcare professionals involved in the provision of footwear for people with diabetes [14, 31], a table of definitions for common terms related to footwear for people with diabetes was developed based on literature [15, 16, 32, 33] and expert opinion (Table 1).

The first draft of this guideline was written by the first author (JvN), and then sent to two co-authors (PAL and PW) for critical review and expert opinion. A second draft incorporating consensus feedback from the three authors was sent to all authors for critical review and expert opinion feedback. The authors of this guideline, all (inter)national experts in the field of diabetic foot ulcer and footwear management, came from the following backgrounds: podiatric medicine (n = 5), podiatric surgery (n = 1), human movement science (n = 2), wound medicine (n = 2), pedorthics (n = 1), rehabilitation medicine (n = 1), endocrinology (n = 1), and vascular surgery (n = 1). A third draft incorporating feedback from all co-authors was written by the first author (JvN) and again sent to all co-authors for review. This process was repeated one more time, until consensus was reached from all authors, leading to the final version of the guideline, approved by all authors.

The purchase and wearing of appropriate footwear is an important process of care for all individuals with diabetes. This importance increases as the individual’s risk for developing a foot ulcer increases. Different classifications for foot risk status are used worldwide. For the purpose of this Australian footwear guideline we followed the classification provided in the Australian NHMRC guideline [31]:

According to the NHMRC guideline, Aboriginal and Torres Strait Islander people with diabetes are considered to be at high-risk for foot ulceration, until the person’s level of risk is adequately assessed and confirmed otherwise [31].

To determine foot risk status, all people with diabetes should undergo at least a yearly foot screening by an appropriately trained registered healthcare professional with demonstrated competency [14, 31]. People with an intermediate- or high-risk foot status should be screened at least once every 3 to 6 months [14, 31]. In accordance with the NHMRC guideline, this should consist of screening for peripheral neuropathy (10 g monofilament sensitivity; vibration perception; neuropathy disability score), peripheral artery disease (palpation of peripheral pulses; ankle-brachial pressure index; toe-brachial pressure index), foot deformity (six point scale scoring small muscle wasting, Charcot foot deformity, bony prominence, prominent metatarsal head, hammer or claw toes and limited joint mobility), and assessment of a history of foot ulcer(s) or lower-extremity amputation [31]. The Australian Diabetes Society has published a video-example of such a foot examination [35].

This guideline consists of three parts and a discussion. Firstly, footwear recommendations and their rationale are provided for people at-risk of foot ulceration; These recommendations apply to people at low-, intermediate- or high-risk. Secondly, additional specific footwear recommendations and their rationale are provided for people at intermediate- or high-risk of foot ulceration. Thirdly, footwear and offloading recommendations for people with a diabetic foot ulcer are summarised. Finally, considerations on footwear provision, on education and adherence, on cultural and geographical differences, and on methodology and terminology are discussed.

When providing footwear to a person with diabetes, ensure they know their foot risk status and confirm this via an evidence-based screening by an appropriately trained healthcare professional [31]. In addition to the foot screening, other factors that should be considered include the person’s gait pattern, activity levels, occupation, level of mobility, living situation, cultural beliefs, personal goals, and preferences. These factors may influence the possible options for appropriate footwear.

When providing footwear, measure the length, width, depth and girth of the foot the footwear needs to accommodate and ensure that the footwear follows the criteria in Tables 3 and 4. For length and width, we suggest at a minimum using a Brannock measuring device [44]. Although new scanning devices are becoming available to measure foot shape, we still suggest depth requires clinical assessment until accuracy of these devices can be independently quantified, taking into account that people with peripheral neuropathy cannot feel whether depth is accurate. Evaluate the shoe fit with the person in standing position, preferably at the end of the day to ensure that any developing oedema is taken into account. Further considerations in relation to oedema are footwear height (high footwear may have a compression function), outdoor temperature, and changes in oedema treatment.

The timing of footwear provision is important for any footwear that is not pre-fabricated. This becomes even more important when a person with diabetes at intermediate- or high-risk does not have appropriate footwear at a given moment. The longer a person needs to wait to receive appropriate footwear, the more steps they will take in inappropriate footwear, potentially increasing the repetitive stresses on the foot and in turn the risk for foot ulceration. Timing is most important for people with a recently healed plantar foot ulcer. Delivery of their prescribed footwear should be coordinated to a point as close to healing as possible. Ideally, the transition from an offloading device required to heal the ulcer to the preventative footwear is immediate. Any delay in this transition increases the risk of ulcer recurrence. When appropriate preventative footwear is not available for a person with a nearly healed foot ulcer, footwear prescription should be initiated before the ulcer is healed. Prescription can be initiated when foot shape (especially volume), structure and function are not expected to change during the healing process, and should take the manufacturing time-schedule into account. When prescribed footwear cannot be made available immediately when the ulcer has healed, continuation in the offloading device meeting the offloading requirements is needed until the prescribed footwear becomes available. Further, when new footwear is provided to a person with diabetes after healing a foot ulcer, advise them that a “wear-in” period may be needed where they alternate the new footwear with the offloading device that was required to heal the ulcer, and that they should be extra vigilant with checking of their foot health in this period.

In Australia, various state-based schemes are available that may provide financial assistance to people with diabetes who require medical-grade footwear. However, these schemes change over time and discussion of the specific schemes is outside the scope of this guideline.

Early education on the importance of adequate footwear for foot health is important for all people with diabetes. This education needs to continue life-long, and needs to be expanded if a person’s level of risk of foot ulceration increases. The importance of footwear for people with diabetes should be discussed in the context of the individual’s foot risk status and health literacy [45]. Education should aim to increase people’s understanding of the requirements of their footwear to adequately fit, protect and accommodate their feet. This may also include, but is not limited to, education on proper donning of the footwear, the importance of wearing socks in footwear to reduce shear and friction, and explaining the risks to foot health of inappropriate footwear such as slippers and sandals, of narrow heels, of heels higher than 3 cm, and of pointy, flat or hard toe boxes. Education should further focus on motivating people with diabetes at intermediate- or high-risk of foot ulceration to wear their footwear at all times. Footwear can only be effective when it is worn, and adherence to wearing footwear is an important factor in foot ulcer prevention [17, 23, 26, 30].

Achieving better adherence is a challenge, and unfortunately we found no intervention studies on the effect of interventions that aim to increase footwear adherence in people with diabetes [17, 41]. However, we found a number of observational studies investigating reasons for (non-)adherence to footwear [26, 28, 45‐49]. An improvement in walking has been described as the most important footwear-related characteristic affecting adherence, while the importance of cosmetic appearance and ease of use varies greatly between people [28, 48]. Rather than focussing on footwear characteristics, it is suggested in various studies that personal perceptions, values and experiences are more important factors to improve adherence [26, 28, 45‐49]. A perceived benefit of footwear is associated with increased adherence to wearing the footwear [26], and conversely, a lack of understanding of the need for footwear hinders adherence [28]. Acceptance of the need for footwear is another important factor affecting adherence [28, 46, 47]. This does not only concern accepting the need for footwear, but also acceptance of the person’s underlying diabetic foot disease [28, 46, 47]. Footwear has been described as a “visible representation of the disease”, and people with diabetes at-risk of foot ulceration may choose to moderate their adherence to align with functional requirements and societal norms [28, 46, 47].

These personal values and experiences cannot be assessed using a standardised measurement device. Adequate communication between healthcare professionals and patients is needed to assess these perceptions [45, 50]. For this communication to be effective, it should be person-centred, not footwear-centred [45, 50]. Footwear is very personal, and this should be taken into account during education and communication to ensure maximum acceptance of and adherence with the footwear provided [28, 47, 50].

For people at intermediate- or high-risk of foot ulceration, the importance of adherence to wearing appropriate footwear both indoors and outdoors needs extra attention. People at risk of foot ulceration have been found to perform the majority of their total daily steps indoors [30, 42], while their adherence to wearing their footwear is significantly lower indoors compared to outdoors [30]. To improve adherence, people may need to be made aware of the greater repetitive stresses on their feet when at home resulting from the greater number of steps. It has also been suggested to provide separate footwear for indoor and outdoor use [30]. For people from cultures that may prefer not to wear ‘normal’ footwear indoors, it is suggested that health professionals consider providing indoor footwear that is manufactured to not look like ‘normal’ footwear, which may then be more acceptable to be worn indoors.

In this guideline, we describe features and criteria for footwear for people with diabetes, and specific recommendations based on a person’s foot ulcer risk following the NHMRC risk classification. Footwear is very personal and multiple other factors may need to be taken into account when providing footwear to a person with diabetes and ensuring this footwear is being used. We acknowledge the cultural differences in regard to footwear behaviour, specifically for Aboriginal and Torres Strait Islander people and from other diverse ethnic backgrounds. Furthermore, individuals in geographically rural and remote areas of Australia may have a limited range of footwear options available to them, and limited access to appropriately trained professionals. However, we decided not to provide specific recommendations for different cultures or for people living in rural and remote areas. The criteria and recommendations in this guideline are to be seen as the standards to be achieved, and these recommendations can be used by clinicians in their communications to discuss the footwear requirements for each person’s situation. Specific circumstances may require that a compromise is made to the recommendations, which then may be considered to be better than no footwear at all. However, in our opinion, offering deviations from the standards in this guideline, without supporting evidence and solely based on specific cultural or geographical backgrounds of people, does not align with offering equality of best practice care for all people and may increase the risk of foot ulceration and will weaken this guideline. Rather, we encourage healthcare professionals to use this guideline to discuss footwear requirements with people with diabetes, to try and achieve, if needed, a compromise that is optimal for the person’s situation that most closely aligns with the requirements and recommendations described in this guideline.

We have based this update of the 2013 guideline on contemporary evidence-based guidelines [10, 14, 15, 31], scientific evidence from systematic reviews [17‐22], randomised controlled trials [23, 24], observational studies [9, 25‐30, 32‐34], and expert opinion, involving experts from eight different disciplines involved in the treatment of people with diabetic foot disease. However, this should not be looked upon as an evidence-based guideline, as we did not follow a specific guideline development methodology. Developing evidence-based guidelines is an extensive and costly process. With recent studies providing a much stronger evidence-base for footwear requirements for people with diabetes we felt that a new footwear guideline to update information in the NHMRC guideline [31] and the 2013 Australian practical guideline on footwear provision [16] was more important than waiting for completion of a full evidence-based guideline. Compared to the recommendations from the 2013 guidelines, some have not changed, and a number of new ones have been added. These include the need for health professionals to prescribe medical grade footwear that has demonstrated plantar pressure reducing effects at high-risk plantar areas for those people with a healed plantar foot ulcer, to review the adequacy of any prescribed footwear every three months, and to treat a plantar foot ulcer primarily with appropriate offloading devices. With this current document, healthcare professionals can immediately start to implement the new footwear evidence to begin to further reduce the large national burden of diabetic foot disease.

The specific footwear requirements are closely related to an individual’s foot risk status. This means that to provide people with diabetes with appropriate footwear, their foot risk status must be assessed first. We followed the classification as provided in the NHMRC guideline [31]. Other countries may use different risk classifications, and we advise healthcare professionals to ensure they use the guideline that is applicable in their own country with regard to foot risk status assessment. In this guideline, we did not separate between intermediate- and high-risk. The first reason for doing so was that some recommendations do not depend on foot risk status per se, but on the presence (or absence) of the specific risk factors of foot deformity or previously healed ulcer. To cover these differences, specific recommendations were needed that applied both to people at intermediate- and high-risk. Further, combining both groups while including specifically targeted recommendations also gives healthcare professionals from other countries the opportunity to match the recommendations in this guideline with their own country’s foot risk status classification system. Finally, the recommendations that did not target a specific risk factor were similar for people at intermediate- or high-risk, which means they could be combined.

As recommended in this guideline, people at intermediate- or high-risk of foot ulceration should be instructed to obtain their footwear from an appropriately trained professional with demonstrated competencies in footwear fitting for people with diabetes. We have not defined ‘appropriately trained’ or ‘demonstrated competencies’, as that was beyond the scope of the current document. However, as a minimum, we suggest an appropriately trained professional should be able to show documented evidence of their training and competency, and should meet the standards of their profession when such standards are available. This way, other healthcare professionals may confidently inform people with diabetes where to obtain their footwear.

The methodology followed to write this guideline does have some limitations. The first, not following a guideline development methodology, has been discussed above. A second is that no patient advocates were involved in its creation. This is a consequence of not following a specific guideline methodology, and we hope that this will be done in the next update of the NHMRC guideline [31]. A third is the limited evidence base with regard to the recommendations for people at low-risk of ulceration [17, 41]. These recommendations might be seen as “good practice statements”, a terminology used in official guideline development for recommendations that are predominantly based on expert opinion and standard of practice, when limited evidence is available [51]. As argued in other publications, it is hoped that researchers and healthcare providers combine efforts to build a stronger research evidence base for these recommendations [41]. Finally, we are unaware of cost-effectiveness information for any of the proposed footwear interventions [17], and thus no such specific information can be added to this guideline. However, a recent Australian cost-effectiveness analysis reported appropriately prescribed footwear as part of a suite of optimal diabetic foot care practice was always cheaper than standard care, and with the high costs associated with foot ulceration [1, 52, 53], it is likely that preventative footwear efforts in this regard will be cost-saving [41].