Prevention of diabetic foot complications

Education as the most important strategy

The key to prevention of diabetic foot problems is education. While this should be mainly directed at patients and caregivers, professionals must first be educated so that they understand the nature of patient education. Once trained and educated, they can then provide effective education for patients and caregivers.

There is controversy in the literature about the effectiveness of patient education in preventing diabetic foot ulcer (Table I). With regard to preventing ulceration and below-knee amputation, Malone et al(9) found, in a randomised controlled study, that the amputation rate in the control group was three times higher than that in the intervention group (p < 0.05). In addition, McMurray et al,(10) in a randomised controlled study involving end-stage renal failure patients, found significant improvement in self-knowledge in the intervention group (p < 0.001). They also found five amputations in the control group, versus no amputations in the intervention group (p < 0.05). In a blinded randomised controlled trial, Litzelman et al(11) also found the intervention group to be less likely to develop foot lesions (p = 0.05). The intervention group also demonstrated self-foot care behaviour (p < 0.001). However, Lincoln et al,(12) in an observer-blinded randomised controlled study, reported no significant difference in the two groups in terms of ulcer incidence at six months and amputation rate. The effectiveness of patient education may depend on the type of teaching pedagogy employed.(13) While Kruger et al(14) reported that hands-on teaching was ineffective compared to didactic teaching, Gershater et al(13) showed that group discussion is not an ideal method (Table I). More research is needed on the effectiveness of different teaching methodologies utilised.

Table I

Studies of patient education programmes.

Despite the controversy regarding the usefulness of patient education, several guidelines have recommended that care of the foot be taught to patients and caregivers(15-18) along with the use of appropriate footwear.(15,16) The International Working Group on the Diabetic Foot strongly recommended education on footwear and encouraged education for foot care.(16)

Professionals who require education include general practitioners, doctors, nurses and allied health professionals in hospitals and primary healthcare centres. Box 1 shows educational materials such as books, websites and guidelines that are available for training professionals.

Box 1

Materials for professional education.

Nevertheless, the main thrust of our education efforts should be directed at patients and caregivers. Education must be provided in three different areas: care of diabetes mellitus, care of the foot and choice of footwear. We found that patients usually do not understand diabetes mellitus and do not manage it well. They often present with a glycated haemoglobin (HbA1c) level of 10.0% or more. In our 2014 study on the effectiveness of the multidisciplinary team approach to treat diabetic foot, 45% in a cohort of 206 patients had a HbA1c level of more than 10%.(25) Hence, our education efforts should focus on first teaching patients about diabetes mellitus and its care, including diet, exercise and medication. Next, we must educate them on foot hygiene and care of the foot. Finally, attention must be given to the use of appropriate footwear.

Patient education materials that are available include books(26) and online materials (Box 2). Other materials include patient education pamphlets given by institutions. The pamphlets given to patients in our hospital included ‘Knowing Diabetes’, ‘Happy Feet’ and ‘Patients’ Guide for Footwear’.(17)

Box 2

Materials for patient education.

Foot screening

The effect of foot screening in reducing diabetic foot wounds is controversial. Lavery et al(27) showed that a combination of foot screening and education was able to decrease the incidence of amputation by 47.4% (p < 0.05), as well as reduce average inpatient length of stay by 21.7% (p < 0.05). However, in a retrospective case-control study involving 61 Pima Indian patients with prior amputation and 183 controls without prior amputation, Mayfield et al(28) found that receiving one or more foot care examinations does not significantly reduce the risk of amputation (p = 0.31). More prospective research is needed.

In addition, the frequency of foot screening may affect its outcome. More research is needed to evaluate the effect of different frequencies employed. In our hospital, all diabetic patients are subjected to annual foot screening in addition to yearly eye screening, heart screening and kidney screening.(29) The strategy of the Ministry of Health, Singapore, is to screen diagnosed diabetics as early as possible at the primary healthcare level.

The ‘foot at risk’

The purpose of foot screening is to detect signs of the ‘foot at risk’. This refers to a foot with the potential to ulcerate. The four key signs of the foot at risk are loss of protective sensation (peripheral neuropathy), one or both distal pulses not being palpable (peripheral arterial disease), presence of foot deformity or callosity, and inability to reach the foot or visual impairment.(16) The risk stratification tool by Leese et al can be used to predict the risk of foot ulceration.(30) The tool classifies the foot into one of three categories: low, moderate or high risk (Fig. 2). This stratification is based on four clinical criteria: patient history, foot pulses, monofilament testing and foot deformity.

Fig. 2

Foot risk stratification scheme.(30)

Methods of foot screening

There is no standardised protocol for foot screening. The different screening methodologies used by the various institutions are shown in Table II.

Table II

Different foot screening methods.

Our institution’s protocol consists of clinical history and examination (including neurological and vascular assessment), measurement of the ankle-brachial index (ABI) and toe-brachial index (TBI), the monofilament test and neurothesiometer test, foot risk stratification, foot care education and a management plan.(29) ABI/TBI measurement is not done in the American Diabetes Association’s protocol and the NHS (National Health Services) Scotland’s protocol. Singapore’s Ministry of Health intends to conduct foot screening on a national level, and future screenings will not include ABI/TBI and neurothesiometer measurement. Foot screening aims to detect the foot at risk, including the absence of a palpable pulse (can be detected clinically). Hence, there is no need for the ABI/TBI, which requires additional equipment and taking up more steps for screening. Furthermore, the monofilament test is able to reveal the clinical presence or absence of neuropathy, and therefore, the neurothesiometer is also not necessary.

Government intervention

In the United States, the country with the highest proportion of diabetic patients among developed countries,(2) the government of each state funds national campaigns and programmes to lower the prevalence of diabetes mellitus. The United Kingdom has implemented the DESMOND (Diabetes Education and Self-management for Ongoing and Newly Diagnosed) programme since 2003. This programme has not made a significant impact on glycaemic control, but has shown a better understanding of diabetes mellitus among patients.(34)

Government involvement is crucial for successful prevention on a national scale. It is noteworthy that the Minister for Health, Singapore, ‘declared a war on diabetes’(1) in April 2016. It initiated two ministerial task forces, one on Diabetes Prevention and Care and a second task force to promote a healthy lifestyle. Such government intervention needs to be long and sustained. Intervention is important not only to address diabetes but also other chronic related diseases, such as hypertension, ischaemic heart disease, stroke and renal impairment.