Foot Care Interventions for Low-risk Diabetic Patients and those Without Foot Ulcers: A Mapping Review

Aim of mapping review

This mapping review is employed to identify existing evidence on intervention for diabetic patients at low risk of DFUs and without DFUs delivered by health care professional (HCP) (medical doctors, nurses, midwives, dentists and pharmacists) to identify the core components of foot care intervention (FCI). More specifically, the objectives are to: identify the components of an intervention, including method of delivery, procedure, intervention provider, pre-existing specific skill, location of intervention, place and duration of intervention, and intervention content (Hoffmann et al., 2014). This review was undertaken using the Joanne Briggs Institute (JBI) guidance for conducting and reporting scoping reviews (which also applies to mapping reviews) (Campbell et al., 2023), and the Preferred Reporting Items for Systematic Reviews extension for Scoping Reviews (PRISMA-ScR) (Peters et al., 2020).

Population

This mapping review focused on investigating studies involving patients with type 2 diabetes mellitus (T2DM) who are over 18. T2DM is the most common type of diabetes and accounts for over 90% of all diabetes cases worldwide. The initial assessment revealed limited studies that specifically targeted patients with low-risk foot ulcers. To obtain more evidence on this topic, we explored the evidence of FCIs provided by HCPs for patients with T2DM who fall into one of the following categories: (1) low-risk foot ulcers; (2) no current foot ulcers or without DFUs; or (3) those who receive FCI as part of their diabetes management in general, but without DFUs.

The exclusion criteria for this review included studies that focused on healthy individuals or those with medical conditions other than diabetes, individuals with active foot wounds, those suffering from severe psychiatric or cognitive disorders, or those who have experienced major diabetes complications such as proliferative retinopathy, cardiovascular disease, or lower limb amputation.

Concept

Interventions included structured education on footcare or self-care using different forms of health prevention, applying different methods, at various intervals, of different lengths, and with different educators, to help identify the appropriate method for a particular target population. FCIs consisted of basic foot information components for diabetic patients, including daily foot checks, receiving professional footcare and assessment, keeping feet clean and dry, protecting feet from temperature extremes, wearing appropriate footwear, minimizing the risk of foot complications, and exercises related to the legs (RNAO, 2007; ADA, 2020; Bus et al., 2020). The review only considered interventions delivered by HCPs.

Context

We assessed reported foot health outcomes, including indirect outcomes related to ulcer prevention, such as footcare behaviour assessment scores, knowledge and practice scores, and adherence to foot self-care. However, studies that only reported physiological interventions (such as muscle or nerve electrical stimulation), or general self-care interventions without foot-related content (such as insulin or BP monitoring and nutritional education) were excluded.

Study types

We considered comparative studies such as randomized controlled trials, non-randomized controlled trials, before-and-after studies, and interrupted time-series studies. To enable data analysis related to risk and benefits, observational (prospective and retrospective) and case-control studies were included. Qualitative studies comprised phenomenology, grounded theory, ethnography, action research and feminist research. Secondary research encompassed narrative reviews, evidence summaries, or systematic reviews, to gain a broad assay of the evidence. Opinion pieces, editorials and books were excluded. Studies not available in English or via the University library were excluded from this mapping review.

Search strategy

A four-step search strategy was designed to find relevant published and unpublished resources.

We searched the following electronic databases for peer-reviewed articles from the dates first indicated until June 2021. An initial step applied a scoping search, with a narrow preliminary search of PubMed, EMBASE, and CINAHL, using a set of search terms around the major theme of the review question about the core component of FCI to identify an initial set of free-text and thesaurus terms.

We then implemented a comprehensive search using Medical Subject Heading and text words. The search terms were:

These words were chosen to encompass all potential articles, as very few papers focused on foot care for low-risk and non-ulcerative feet have been published based on preliminary studies. The following databases were searched: CINAHL Plus with full text, EMBASE, (Ovid), Medline (Ovid), PubMed (Ovid), Cochrane Library, Scopus, and Science Direct, ASSIA. APA PsycArticles. Unpublished studies were retrieved from ProQuest Dissertations and Theses.

We undertook a third search for institutional or organizational websites with public policies using the term (Guideline OR Consensus) AND (“footcare”) for the first 20 pages of the Google search. A search was carried out on 21st April 2021 and found 23 websites. Studies included after the full-text review had guidelines in English and were strictly about the topic area; evidence-based (e.g., containing references descriptions of the evidence, and sources of evidence); and available and accessible for retrieval.

Finally, we searched the reference lists of all identified articles for additional studies (commonly referred to as a citation search).

Data management: Study selection and data collection process

All identified articles from database searching were collated, and data were subsequently imported into EndNote VX9.1 (Clarivate Analytics, PA, USA). Duplicate articles were removed using EndNote, and other articles were deleted manually after first author had examined the titles and abstracts of studies. After all duplicates were removed from included data, titles and abstracts were screened for assessment against the inclusion criteria for the review. The full text of included studies was retrieved and assessed in detail against the inclusion criteria. Contact with the authors of selected articles was undertaken for missing information if needed.

The PRISMA flow diagram (Page et al., 2021) for the search and selection process in this review is presented in Figure 1.

Figure 1. PRISMA flow diagram.

Data extraction

Data were extracted from each publication and included in an evidence-based table using standard data extraction tools available at JBI SUMARI (Tricco et al., 2018). These data had participant and study characteristics, research methods, intervention, and primary and secondary outcomes. The first author extracted the data and checked the data for content included in the table and rechecked by the second author.

Data analysis and synthesis

Disagreements or differences in the table were discussed with the other authors. The results presented in the evidence table included references, study design, population and outcome categories of intervention. A narrative synthesis was then used to summarize key findings from each study group based on type of study or specific intervention for type of risk of DFUs. The core components of FCI of nine studies delivered by healthcare professionals for T2DM patients ( Table 1) are reported following the checklist and Template Guide for Description and Replication of Interventions (TIDieR) (Hoffmann et al., 2014).

Characteristics of sources of evidence

The studies included in this review were published between 2007 and 2021, with the majority published after 2011. These studies were conducted in diverse countries, including the UK (n = 4), Iran (n = 3), China (n = 2), India (n = 2), Turkey (n = 2), the US (n = 2), and Japan, Canada, and Vietnam (with one study for each country).

Several studies utilized randomized controlled trial designs (n = 5), while others used group pre-test post-test (n = 4), quasi-experimental (n = 2), or cross-sectional study (n = 6) designs. One study did not report its design (Ooi et al., 2007). Qualitative studies were not included in this review, as none reported the specific experiences of diabetic patients with LR-DFUs or without DFUs. Observational (prospective and retrospective) and case-control studies related to the risk of DFUs were presented in the review but were not examined for intervention components (supplementary appendix A), these studies were included to provide a deeper understanding of the area related to the risk of DFUs.

Intervention for patients with LR-DFUs

Three articles reported FCIs for diabetic patients with LR-DFUs; two reported on one study conducted in Canada (Fan et al., 2012, 2013), and one study was conducted in Vietnam (Nguyen et al., 2019). To improve the effectiveness of DSME, both studies provided hands-on skills taught by nurses, followed by phone contact boosters. In Vietnam, Nguyen et al. (2019) used small-group education, whereas Fan et al. (2019) provided one-on-one patient interaction in Canada. The intervention groups had positive outcomes in encouraging positive behaviour towards self-footcare, lowering the prevalence of foot risk factors for ulceration, and effectively reducing the occurrence of minor foot skin and toenail problems.

Observational and case control studies related to the risk of DFUs

Cohort studies and case-control studies are two primary types of observational studies that aid in evaluating associations between diseases and exposures. Cohort studies can be prospective or retrospective (Song & Chung, 2010).

Two cohort studies that evaluated footcare programmes based on foot risk classification (Harwell et al., 2001; Kishore et al., 2015; Pollock et al., 2004; Wei et al., 2019; Liaofang Wu et al., 2015) (supplementary appendix A). Wu et al. (2015) conducted a study in China to investigate the prevalence of risk factors among diabetic patients and found that 35% of patients were considered low risk, while 49% were at high risk for feet ulceration. In India, Kishore, Upadhyay and Jyotsna (2015) revealed that almost half of the diabetic patients attending a tertiary care centre had a foot at risk. Increasing duration of diabetes, lower educational, lower socioeconomic status and level of healthcare have significant correlation with foot at risk (Kishore et al., 2015).

Harwell et al.’s (2001) cross-sectional study in the US claimed that 30% of respondents were at high risk for future foot complications, and such patients were more likely than their low-risk counterparts to report having an annual foot examination, use protective footwear, and perceive themselves to be high risk for future foot complications. In the UK, Pollock, Unwin and Connolly (2004) reported that most patients had received some form of advice, with greater prevalence among high-risk patients (85.6%, 79.8–91.5) than their low-risk counterparts (77.1%, 68.1–86.2), responses to the knowledge questions revealed higher scores for high-risk patients, but there was no statistically significant difference in these scores (p = 0.21) (6.8/11 and 6.5/11 for high- and low-risk patients, respectively), and the high risk patients’ footcare practice was better than the low risk patients’ foot care practice (Pollock et al., 2004). In summary, these studies emphasize the need for targeted footcare education and interventions to avoid further increasing DFUs risks.

It should be emphasized that one study conducted in the UK by Heggie et al. (2020) presented differing perspectives on the topic of annual screening for patients with LR-DFUs. A recent epidemiology study examined the cases of 10,421 individuals with diabetes who underwent foot screening at an NHS outpatient clinic. The study analysed data collected between 2009 and 2017 on patients diagnosed with diabetes during their first visit to screening clinics in Fife, Scotland (Heggie et al., 2020). The research found that individuals with diabetes gradually transitioned from low to moderate risk. After two years, 5.1% of low-risk patients became moderate-risk, while around 9.9% and 11.3% changed after five and eight years, respectively. Peripheral neuropathy in the feet was the cause of risk status changes for the vast majority (94%). Additionally, only 0.4% of low-risk patients developed ulcers after two years, with 0.1% requiring amputation.

The study concluded that annual screening for low-risk individuals demands substantial National Health Service (the UK government funded medical and healthcare service) resources, which may hinder other preventative measures. There is no clear evidence to support this recommendation, and the optimal screening frequency remains uncertain. For individuals with T2DM, the risk of ulceration remains relatively constant over an 8-year timeframe. It may be suitable to modify the monitoring schedule from yearly to every two years for individuals at low risk (Crawford, Chappell et al., 2020a).

Core components of intervention (using comparative studies)

The mapping review identified key themes related to the core components of FCIs (Hoffmann et al., 2014).

The core components of interventions could not be extracted from observational studies (cohort studies and case-control studies), because a cohort of subjects was selected based on exposure status, and outcome data (i.e. disease status, event status) (Song & Chung, 2010) whereby experimental (randomized or non-randomized design) comparative studies identify and assign samples of participants to different treatment groups for a given time duration, and analysis of their outcomes enable conclusions to be drawn which (subject to the nature of study setting, participants, intervention, measures, analysis and interpretations etc.) can produce results that can be generalized for other analogous settings (Lau & Holbrook, 2016). However, the FCI as part diabetes self-management education (DSME) in general (supplementary appendix B) could not be used for further descriptive analysis, since no specific information was available on FCI (Eroglu & Sabuncu, 2021; Ghavami et al., 2018; Yang et al., 2020).

This review examined the experimental study of FCI for diabetic’s patients to gather information about intervention components. Table 1 presents the key data extraction from the included nine studies for patients with LR-DFU and without DFU, and Table 2 presents the core components of the interventions nine studies.

Sample characteristics of comparative studies

The comparative analysis comprised nine studies conducted in various countries, including Canada, India, Iran, Japan, the UK, the US, Turkey, and Vietnam. The studies included participants from both high and low-resource countries, with sample sizes ranging from 56 to 324 participants. However, most of the included studies did not report specific clinical outcomes which measure success of FCI such as the incidence of foot ulceration, amputation, callus development, fungal infection, or duration of hospital admission for DFPs (Dorresteijn & Valk, 2012). Two studies did report the effectiveness of FCI in reducing minor foot skin and toenail problems at a 3-month follow-up for diabetic patients with LR-DFUs (Fan et al., 2013) and free of tinea pedis (Fujiwara et al., 2011).

Nonetheless, all studies reported process outcomes, such as footcare knowledge scores and patient behaviour assessment scores, as expected outcomes in patient education for preventing DFUs. Statistically significant improvements were observed in footcare knowledge (Dincer & Bahçecik, 2021; Fan et al., 2013; Ooi et al., 2007; Rahaman et al., 2018) footcare behaviour (Borges & Ostwald, 2008; Dincer & Bahçecik, 2021; Fan et al., 2014; Fardazar et al., 2018; Moradi et al., 2019; Nguyen et al., 2019), self-efficacy (Borges & Ostwald, 2008; Dincer & Bahçecik, 2021; Fan et al., 2014), and footcare practice (Rahaman et al., 2018).

Educational contents

The material provided to participants encompassed basic footcare information including:

This review also identified data about content of diabetic FCIs from manuals of footcare education from websites and organizations and also through citation searching. Reports were identified from various organizations, including the National Institute for Health and Care Excellence (NICE, 2020), the American Diabetes Association (ADA) (Boulton et al., 2018), and the International Working Group on Diabetes Foot (IWGDF) (Bus et al., 2020), along with “Footcare education in Diabetic patients at low risk of complications: a consensus statement” (McInnes et al., 2011) (supplementary appendix C). These manuals provide DFU risk classification and the steps that should be followed by patients according to their risk classification.

Patients with no risk factors present except callus alone (NICE, 2020), or who are categorized as being at the low-risk grade 0 based on the IWGDF classification (Bus et al., 2020), are advised to have annual foot assessments with the importance of footcare being emphasized, and patient’s aware-raising is recommended for those who may progress to moderate or high risk (NICE, 2020). In addition, the ADA (Boulton et al., 2018) recommends that patients with a very low risk (ADA risk category 0) should engage in education on topics such as routine footcare, athletic training, appropriate footwear, or injury prevention while patient with low-risk of foot ulcers (ADA risk category 1); loss of protective sensation (LOPS) ± longstanding, non-changing deformity also requires prescriptive or accommodative footwear.

Patients at moderate or high risk of developing diabetic foot problems (DFPs) are referred to foot protection services (NICE, 2020). All other categories are considered “at risk” or (IWGDF risk 1-3), and require more frequent foot screening, regular inspection, and foot examination than patients who are not at risk. Patients at risk of DFUs are advised to protect their feet by not walking barefoot, in socks without shoes, or in thin-soled slippers, whether indoors or outdoors (Bus et al., 2020). Patients at risk of foot ulceration (IWGDF risk 1-3) should be instructed (and then encouraged and reminded) to: inspect the entire surface of both feet daily, and the inside of the shoes that will be worn; wash the feet daily (with careful drying, particularly between the toes); use emollients to lubricate dry skin; cut toe nails straight across; and avoid using chemical agents or plasters or any other technique to remove callus or corns (Bus et al., 2020). This educational content is similar with footcare education was recommended by Ireland’s National Model of Diabetic Footcare (National Diabetes Working Group, 2011).

Notably, the IWGDF refers to their document as “Guidance”, rather than a “Guideline”, to underline that these documents are written for a general situation, and may require modifications for specific contexts. As acknowledged in their summary guidance, principles in the IWGDF Guidance need to be adapted to local circumstances. Specific recommendations in the Australian guideline concerning the indigenous population or rural and remote areas exemplify such “local translation” (Diabetic Foot Australia, 2016).

Information available from footcare guidelines taken from several websites indicates that the educational content for medium-risk and high-risk DFUs is similar (National Diabetes Working Group, 2011) and this is also found in personal footcare guidelines for the elderly without diabetes (The Scottish Goverment, 2013). Such basic information used to educate diabetic patients is commonly referred to as “self-footcare educational content”.

Procedure of intervention

Some FCIs were administered to patients after HCPs had examined their feet and determined the risk of foot ulcers (Borges & Ostwald, 2008; Fan et al., 2014; Nguyen et al., 2019). Following the discrimination of the diabetic foot risk category, patients were enrolled in the footcare programme, which HCPs administered according to the diabetic footcare programme. Fujiwara (2011) allocated patients into groups 0–3 according to their IWGDF (2007) diabetic foot risk classification.

Prior to the intervention, patients with a low risk of foot ulcers were screened by evaluation of their foot sensation, circulation, deformities, and prior foot ulceration history. The following were assessed as indicators of low risk for foot ulceration: 1) normal protective sensation as determined by a 10 g monofilament; 2) normal circulation of the lower extremities as determined by the presence of pedal pulses; 3) absence of foot deformities such as bunions, mallet toe, hammer toe, or claw toe as determined by the researcher; 4) patients’ self-report of no history of ulceration or amputation, and the absence of ulceration (Fan et al., 2013, 2014; Nguyen et al., 2019).

Place of intervention

The intervention was conducted in various settings across the studies. One study took place in a hospital (Borges & Ostwald, 2008), while the others were carried out in community health centres (Fan et al., 2014; Moradi et al., 2019; Nguyen et al., 2019), diabetes clinics (Dincer & Bahçecik, 2021; Fardazar et al., 2018), and endocrinology outpatient departments (Fujiwara et al., 2011; Rahaman et al., 2018). The location of intervention was not reported in one study (Ooi et al., 2007).

Intervention provider

The educators who delivered the FCI in the studies reviewed were predominantly nurses (Fan et al., 2014; Fujiwara et al., 2011; Nguyen et al., 2019), podiatrists (Moradi et al., 2019; Ooi et al., 2007), or unspecified HCPs (Borges & Ostwald, 2008; Rahaman et al., 2018). One study used a multidisciplinary approach, involving physicians, nurses, and mental health professionals (Fardazar et al., 2018). Prior to the footcare education intervention, medical doctors assessed minor foot conditions before the nurse delivered footcare education (Nguyen et al., 2019).

In a study that employed multimedia platforms to deliver the intervention, the development was overseen by experts in diabetic foot and mobile technologies. These experts included certified diabetes nurses, certified wound care nurses, university experts in diabetes, university experts in mobile design, teaching technology experts, and software specialists (Dincer & Bahçecik, 2021).

Timing and duration of intervention

The interventions were all administered through face-to-face interaction. The duration of the main session ranged from 20 to 120 minutes for the group. Borges and Ostwald (2008) spent a relatively short time on education (20 minutes) compared to other studies, due to differences in the intervention settings (emergency department).

In two studies (Nguyen et al., 2019 and Fan et al., 2013), participants received a telephone contact booster 2–3 times after the main session, each of which lasted approximately 10–15 minutes, offered once a week over two weeks (Fan et al., 2013, 2014), and three regular booster follow-up phone calls were undertaken over six months (at weeks 2, 10, and 20) by Nguyen et al. (2019).

Multimedia platforms, such as mobile education apps, audio-visual aids, and pamphlets, were utilized in two studies to disseminate information (Rahaman et al., 2018; Dincer and Bahçecik, 2021). The average duration of the intervention in these studies was 9 minutes per session. Borges and Ostwald (2019) conducted a brief FCI in the emergency department while patients waited to complete their visits. The study found no delay in emergency department care or prolongation of the visit when patients received brief self-management footcare education during a short intervention period.

Method of delivery

The educational FCIs were delivered in multiple forms, most often in face-to-face meetings. One study reported using varied methods to convey the information through lectures, practically demonstrating feet examination and special foot exercises, playing films, practicing, group discussion, question and answer, providing educational pamphlets and compact discs (CDs), followed by individual counselling about footcare with the presence of a doctor and diabetes expert, and psychological counselling with a mental health professional provided in the clinic (Fardazar et al., 2018). Individual face-to-face interactions included short patient teaching sessions in the emergency department (Borges & Ostwald, 2008), interactive teaching sessions (Fan et al., 2014) or sessions delivered by a podiatrist (Ooi et al., 2007). Small groups sessions was administered to groups of 8-10 participants in many studies (Ooi et al., 2007; Fujiwara et al., 2011; Rahaman et al., 2018; Nguyen et al., 2019).

Through the telephone contact booster sessions, participants were empowered to solidify their understanding of foot self-care, address any unresolved concerns, and review the critical components of daily self-care practices. This approach serves as a reminder to consistently prioritize these strategies in one’s daily routine (Fan et al., 2014; Nguyen et al., 2019). To support proper footcare and prevent diabetes-related complications, patients were equipped with essential educational materials, including a brochure, booklet, and booklet that outlines footcare procedures (Nguyen et al., 2019). Additionally, a foot self-care kit comprising a basin, a gallon of water, antibacterial non-deodorant soap, a hand towel, a washcloth, an emery board, hypoallergenic lotion, and a mirror was provided (Borges & Ostwald, 2008). Furthermore, one experimental group received suitable socks for diabetic foot prevention (Fardazar et al., 2018).

In addition, Moradi (2019) used text messages to deliver the intervention through the patient’s mobile phone. Over three months, 90 text messages were sent (at a rate of one message per day).

Tailoring intervention

Several studies have been conducted on diabetic FCIs in different countries. In Vietnam, family support was incorporated as an essential aspect of the intervention, considering the cultural norms for elders (Nguyen et al., 2019). Stress management was also included in the intervention in Iran (Fardazar et al., 2018). Mobile phone delivery was utilized in two studies, one of which used animation-based patient education to make education more engaging (Dincer & Bahçecik, 2021).