Abstract

1. Introduction

Foot ulceration is the most devastating complication of diabetes, affecting up to one-third of people with diabetes during their lifetime [1]. It has been reported that the National Health Service in England spends over £1 billion annually managing diabetic foot ulcers (DFUs) and their consequences, which accounts for ~10% of the National Health Service diabetes budget [2]. Notably, these costs are higher than those spent for the treatment of many common types of cancer [3]. Furthermore, 20% of people with a DFU may require lower extremity amputation because of moderate to severe infection. This complication results in frequent and long-term hospitalisations and an increase in mortality at five years, which may exceed 70% in some patients [4].

Crucially, a DFU is responsible for deterioration in physical function and loss of independence in people with diabetes, resulting in psychological distress and poor quality of life [5]. Moreover, a third of people with their first DFU suffer from clinical depression. This condition is associated with an increased amputation and mortality risk compared with people with no evidence of clinical depression [6].

Although most research to date has focused on psychosocial consequences of DFUs, a growing number of studies investigate the psychological antecedents of patient engagement in preventive foot self-care [7]. Among commonly examined psychological constructs are patient cognitive and emotional representations of DFU risk [8,9,10], depression [11,12,13], personality traits [14], and cognitive functioning [10,15]. The strongest evidence so far supports the link between patient common-sense interpretation of their DFU risk and associated emotional responses, and preventive foot self-care [7,8,9,10].

Several reports showed that psychological and behavioural factors predict the first, but not recurrent DFUs [12,13]. A recent systematic review [16] reaffirmed these findings indicating that psychosocial and behavioural factors play a role in the development of first DFUs and proposed that more research is needed to determine whether these factors influence DFU recurrence. The observation that basic foot care behavioural strategies are ineffective for secondary DFU prevention was also supported by a randomised controlled trial, where the intervention group reported an improved foot self-care; however, no significant differences in DFU recurrence were observed between the control and intervention groups [17]. A subsequent study examined the role of motivational interviewing in DFU prevention and demonstrated that people with prior DFUs reulcerate despite motivational interviewing, as this group has biological DFU risk factors that are beyond control by this type of intervention [18]. The observations from descriptive and interventional studies therefore necessitate a search for more effective foot selfcare behavioural strategies, especially in secondary DFU prevention.

As we live in the era of rapidly improving medical technologies, smart wearable devices are being developed for ongoing monitoring of DFU risk factors, with the aim of DFU prevention through monitoring parameters, including foot pressure [19]. These technologies are highly effective in reducing DFU recurrence through improved foot self-monitoring [20]. Wearable devices have also been developed for monitoring wound healing and inflammatory biomarkers (i.e., cortisol, glucose, and interleukin-6), promoting them as a tool for managing diabetes and DFU [20].

Currently, intelligent socks and insoles are the main available wearable devices that show promising results in the prevention of DFU [21]. In particular, smart socks—an optical fibre-based smart textiles–allow the measurement of plantar foot temperature, whereas insole devices monitor plantar pressure through specific sensors. Both devices may alert patients via a mobile interface (e.g., smartphone or smartwatch) to modify their behaviour. Recently, a proof-of-concept study conducted in the UK demonstrated that DFU recurrence can be significantly reduced by 71% compared to the standard of care by providing timely feedback on foot pressures to individuals through smart insoles [19].

Although promising, smart wearable devices introduce additional layers of complexity in preventive foot self-care for people at high risk of DFU, and present challenges for digital literacy. Currently, information about the patient and provider perspectives on smart wearable devices and factors is limited, or facilitating their use is lacking. Several systematic reviews that have evaluated smart technology in diabetic foot disease either focused on the effectiveness of devices and not the patient experience [22], or evaluated patient experience in the management of active DFUs and not DFU prevention [23,24].

Therefore, this systematic review aimed to thoroughly examine the literature on patient and provider perspectives of usability, satisfaction barriers, and facilitators concerning the use of smart wearable devices for preventing DFU in people with diabetes.

2. Materials and Methods

This systematic review followed the preferred reporting items for systematic reviews and meta-analyses (PRISMA) [25]. The PROSPERO register was searched and no prior systematic review of our topic of interest was identified.

3. Results

3.1. Study Characteristics

Figure 1 shows the PRISMA flow diagram. The literature search revealed a total of 1735 articles, of which only 6 were considered eligible for inclusion. Of these, one article was excluded after thorough examination, as it did not meet the inclusion criteria [28]. Thus, a total of five articles were included in the analysis [29,30,31,32,33]. The publication year of these studies ranged from 2017 to 2021. Three articles used a mixed quantitative/qualitative design [31,32,33] and two were quantitative in nature [29,30].

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Figure 1

PRISMA flowchart illustrating the process of study selection.

The characteristics of the studies included are summarized in Table 1. Three of the five studies (60%) were patient-related [29,30,31], one focused on the healthcare provider [33], and one included both patient and provider perspectives [32]. Four articles (80%) considered the use of smart insole devices [29,31,32,33] and one article focused on smart socks [30].

Table 1

Summary of studies exploring patient and provider perspectives on the usability of smart wearable devices in people at high risk of diabetic foot ulcer.

Reference	Study Design	Participants	Clinical Condition	Sample Size	Type of Device	Data Collection Tools	Main Findings
Najafi et al. [29]	Quantitative	Patients	DPN	17	Insoles	Questionnaires	The device and smartwatch were considered easy to use and effective by the patients. A high level of satisfaction was reported. More frequent pressure alerts were associated with better adherence, improvement in offloading, and greater satisfaction with the device.
Reyzelman et al. [30]	Quantitative	Patients	DPN with and without a history of DFU	35	Socks	Questionnaires	Patients described the socks as useful, comfortable, well-designed, and easy to wear. The mobile application was easy to use. Patients were highly satisfied with the device and mobile application.
Macdonald et al. [31]	Mixed	Patients	Diabetic patients with and without a history of DFU	53	Insoles	Questionnaires/focus groups	Attitude, self-efficacy, performance expectancy, and effort expectancy were predictors of the patients’ behavioural intention to use an insole system.
Macdonald et al. [33]	Mixed	Podiatrists	-	111	Insoles	Questionnaires/focus groups	Podiatrists considered the insole device as a useful tool for monitoring diabetic foot disease. Performance expectancy was the main predictor of the intention to use the device in clinical practice. Providers raised several concerns about the cost, type of footwear, and functionality of the insole device with elderly and remote populations.
Macdonald et al. [32]	Mixed	Patients/Podiatrists	DPN	10/2	Insoles	Questionnaires/focus groups	Patient perspective: Performance expectancy, attitude, and behaviour intention decreased significantly after 4 weeks of intervention. The patients were particularly concerned about alert intrusiveness and restricted choice of footwear. Although they appreciated the potential benefits of the smart insole, they did not intend to adopt its current version in the future. Provider perspective: Patients’ negative experiences with the insole device negatively impacted the podiatrists’ view of the device. Although the device was regarded as being useful for foot monitoring, podiatrists were of the opinion that its performance and usability require several improvements.

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Abbreviations: DFU: diabetic foot ulcer; DPN: diabetic peripheral neuropathy.

Four reports [29,31,32,33] used theory-based assessment tools to evaluate patient and provider perceptions of usability and ease of use, whereas one study [30] employed an in-house-designed questionnaire to examine patient levels of satisfaction with the device. The heterogeneous nature of the study designs, aims, and key findings precluded a meta-analysis of the data.

4. Discussion and Conclusions

This systematic review is the first to explore patient and provider perspectives on the acceptance of smart wearable devices in people at high risk of DFU, and to examine the factors limiting or facilitating their use in clinical practice. We identified only a limited number of quantitative and qualitative articles (five studies), which were at moderate-high risk of bias, with quantitative studies rating lower on methodology scores than qualitative studies. The main methodological issues were inadequate sample size, poorly defined recruitment procedures, the lack of psychometric description of the assessment tools, and in particular, the absence of user involvement in the study design. Moreover, the results of these studies were partially conflicting. For example, although the report by Najafi et al. [29] demonstrated that the study participants receiving more alerts in response to elevated plantar pressure adhered better to wearing the device and reported greater satisfaction with the device, Macdonald et al. [32] showed diminished patient responsiveness to alerts and general fatigue with using the device over time. Current evidence is therefore inconsistent, and it is not possible to draw definitive conclusions about patient and provider perspectives on the usability of these devices for the prevention of DFU. Furthermore, only one group of researchers [31,32,33] has explicitly addressed psychological factors influencing patient and podiatrist acceptance of smart wearables. There were differences among patients and podiatrists in factors that influenced their behavioural intention to adopt a smart insole: although attitudes towards smart technology and self-efficacy were key in activating patients, the performance expectancy was a single most important factor motivating podiatrists to adopt smart insoles in their clinical practice. The qualitative findings [32] clarified, at least to some extent, the somewhat unexpected trend towards a significant reduction in smart insole performance expectancy scores: the performance of the device used in this study did not meet participants’ initial expectations. As a result, despite participants’ initial adoption of the smart insole, their attitude and behavioural intention towards future adoption were negatively impacted by their experiences.

These observations highlight an important limitation of the studies that use behavioural intention as a proxy for technology acceptance, thereby providing little insight on actual technology use. Moreover, they do not account for health system complexity and temporality, which require an approach to smart technology adoption as a dynamic and interactive system. This necessitates that as the relationship between people at high risk for DFU and technologies develop, technology implementation is evaluated longitudinally so that emerging issues between people at high DFU risk and care delivery processes can be identified and addressed. Thus, there is a need for timely patient and provider involvement in the development and delivery of such technologies if we are to promote sustained behaviour change. Furthermore, the theoretical models guiding such studies are typically social cognition models and thus do not incorporate DFU-specific domains, such as patient perceptions of their DFU risk or specific emotional responses that were previously identified as important predictors of preventive foot self-care [7].

Thus, adequately powered research is needed to assess longitudinally whether the patient and provider factors identified by these studies are effective in activating people at high DFU risk and in preventing diabetic foot ulceration.

Author Contributions

Conceptualization: G.O., Y.P., N.D.R. and L.V.; methodology: G.O. and L.V.; formal analysis: G.O. and L.V.; writing—original draft preparation: G.O. and L.V.; review editing: Y.P. and N.D.R. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare no conflict of interest.

Footnotes

References