Table 1 Characteristics of included reviews

Author (date) Funding

Objective

Evidence relevant to the overview

Population

Interventions

Comparators

Study designs

Outcomes

Adiewere (2018) [13]

UK

Funding: The Independent Diabetes Trust (UK)

To examine the effectiveness of patient education in preventing and reducing the incidence or recurrence of adult diabetic foot ulceration and amputation

Type I or type II diabetes mellitus or those with diabetic foot ulcers, aged ≥18 years; ulceration risk not specified

Intervention focused on patient education

Not specified

RCTs

Incidence of diabetic foot ulcers; amputation rates

3 RCTs (Additional file 2: Supplementary references S2–S4) (n = 423)

Ulcer risk: high

Outcomes: ulceration; amputations

Meta-analysis

Ahmad Sharoni (2016) [29]

Malaysia

Funding: Not reported

To assess the effectiveness of health education programmes to improve foot self-care practices and foot problems among older people with diabetes

Older people with diabetes, average age ≥ 60 years; ulceration risk not specified

Educational programmes in relation to diabetes foot selfcare that included teaching, coaching, discussion, demonstration, and assessment, conducted by medical personnel

Not specified

Intervention studies (e.g. RCTs, non-randomised controlled study); studies with or without a control group

Primary outcome: diabetes foot self-care

Secondary outcome: foot problems (neuropathy, lesion, ulcer, amputation, foot disability, callus, tinea pedis)

1 RCT (Additional file 2: Supplementary reference S2) (n = 172)

Ulcer risk: high

Outcomes: ulceration; amputations

Narrative summary

Dorresteijn (2014) [15]

Netherlands

Funding: Cochrane review; no additional information

To assess the effects of patient education on the prevention of foot ulcers in patients with diabetes mellitus

Type 1 or type 2 diabetes mellitus, ≥18 years; ulceration risk not specified

Educational programmes or programmes that include education to reduce the incidence of foot ulceration; foot-care education as part of a larger educational programme or a more comprehensive diabetic foot programme

All types of control intervention

RCTs

Primary outcomes: foot ulceration or ulcer recurrence; amputation

Secondary outcomes: Callus development; resolution of callus; fungal infection; number and duration of hospital admissions for diabetic foot problems; foot care knowledge scores; patients’ behaviour assessment scores

2 RCTs (Additional file 2: Supplementary references S1, S2) (n = 225)

Ulcer risk: high

Outcomes: ulceration; amputations

Narrative summary

He (2013) [17]

China

Funding: Not reported

To assess the effectiveness of intensive versus routine education on diabetes mellitus for preventing diabetic foot ulcer

Type I or type II diabetes mellitus, ≥18 years, without current diabetic foot ulcer; ulceration risk not specified

Intensive diabetic education (any time, manner and duration of treatment)

Routine diabetes education

RCTs

Primary outcomes: incidence of diabetic foot ulcers; amputation rate

Secondary outcomes: diabetes knowledge; quality of life

2 RCTs (Additional file 2: Supplementary references S1, S2) (n = 225)

Ulcer risk: high

Outcomes: ulceration; amputations

Meta-analysis

Author (date) Funding

Objective

Evidence relevant to the overview

Eligibility Criteria

Evidence relevant to the overview

Author (date) Funding

Objective

Eligibility Criteria

McGloin (2021) [24]

Ireland

Funding: NIHR (UK) via Cochrane Wounds Group infrastructure funding

To evaluate the effects of psychological interventions on healing and recurrence of diabetic foot ulceration

People with a diabetic foot ulcer or a history of diabetic foot ulcer, ≥18 years; in any care setting

Psychological interventions: CBT; cognitive therapy; psychodynamic therapy; counselling; family systems or systemic therapy; other, as provided by a facilitator.

Standard care, another psychological intervention, education on healing and/or recurrence

RCTs, quasi-RCTs

Primary outcomes: complete wound healing, time to recurrence, number of recurrences

Secondary outcomes: amputations (major or distal), health-related quality of life, self-efficacy, cost

1 RCT (n = 41) (Additional file 2: Supplementary reference S25)

Ulcer risk: High

Outcomes: ulceration

Analysis; narrative summary

Norman (2020) [23]

UK

Funding: NIHR (UK)

Summarise the evidence for the effectiveness of psychosocial interventions to promote healing and/or reduce the occurrence of foot ulceration in people with diabetes

Type 1 or 2 diabetes with or without active foot ulceration; any ulceration risk level

Any individual or group psychological, behavioural or social intervention alone or in combination (eg CBT, motivational interviewing counselling, psychological therapy, social support, mindfulness)

Any, including alternative interventions, usual care, no treatment

RCTs

Primary outcomes: complete healing, ulceration

Secondary outcomes: wound healing rate, amputation, foot care knowledge, adverse events, mortality, psychological outcomes, health related quality of life

6 RCTs (n = 824) (Additional file 2: Supplementary references S1–S4, S12, S14)

Ulcer risk: All levels

Outcomes: ulceration

Analysis: narrative summary

Binning (2019) [27]

UK

Funding: Not reported

To determine whether motivational interviewing has been found to be an effective intervention to improve adherence behaviours for the prevention of diabetic foot ulceration

Diabetes of any type, aged ≥18 years, classified as “at risk” of developing diabetic foot ulceration as defined by the IWGDF, with current or recurrent ulceration or a co-existing risk factor

Motivational interviewing or a motivational approach as the sole intervention or as an intervention component; interventions solely aimed at improving knowledge and skills were excluded

All types of control intervention were accepted

Not pre-specified beyond studies without comparator groups were eligible if they were prospective with a before-and-after study design

A new episode of ulceration and/or at least one behavioural outcome measure

1 RCT (Additional file 2: Supplementary reference S4) (n = 131)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

Author (date) Funding

Objective

Evidence relevant to the overview

Population

Interventions

Comparators

Study designs

Outcomes

Ahmed (2020) [38]

Australia

Funding: None

Evaluate the evidence for footwear and insole features that reduce pathological plantar pressures and diabetic neuropathy ulceration at the plantar forefoot in people with diabetic neuropathy

Diabetes, > 18 years; with or without neuropathy and foot deformity, history of plantar forefoot ulcers but no Charcot foot, history of heel ulcer or active foot ulcers

Footwear or insoles as a long-term offloading intervention; conventional materials and manufacturing techniques; closed-in footwear

Not specified

All study designs except systematic reviews and case reports

Outcomes: (re)-occurrence of forefoot ulcer or change in forefoot plantar pressure

5 RCTs (n = 888) (Additional file 2: Supplementary references S7–S10, S19)

Ulcer risk: High

Outcomes: ulceration

Analysis: Narrative synthesis

Bus (2015) [32]

Netherlands

Funding: Not reported

To assess the effectiveness of footwear and offloading interventions to prevent or heal foot ulcers or reduce mechanical pressure in patients with diabetes

Type I or type II diabetes mellitus; ulceration risk not specified

Casting, footwear, surgical offloading, and other offloading techniques

Not specified

Systematic reviews, meta-analyses, RCTs, non-randomised controlled trials, case–control studies, cohort studies, controlled before-and-after studies, interrupted time series, prospective and retrospective uncontrolled studies, cross-sectional studies, case series

Ulcer prevention, ulcer healing, pressure reduction

7 RCTs (Additional file 2: Supplementary references S5–S11)

(n = 1554)

Ulcer risk: high

Outcomes: ulceration

Analysis: Narrative summary

Collings (2021) [40]

UK

Funding:

NIHR (UK)

To identify the best footwear and insole design features for offloading the plantar surface of the foot to prevent foot ulceration in people with diabetic peripheral neuropathy

Type 1 or type 2 diabetes mellitus, > 18 years; peripheral neuropathy, nonulcerated feet, no major amputation of the foot or Charcot arthropathy

Therapeutic footwear and/or insole

Therapeutic footwear and/or insole design feature compared with another or no intervention

RCTs, non-randomised controlled trials, quasi-experimental, before and after studies, prospective and retrospective cohort studies, analytical cross-sectional studies

Primary outcome: foot ulcer incidence

Other outcomes: kinetic, kinematic or clinical measures of plantar foot loading/offloading, side effects or adverse events

7 RCTs (n = 1357) (Additional file 2: Supplementary references S5–S10, S18, S19)

Ulcer risk: High

Outcomes: ulcer

Analysis: Narrative summary of RCT data

Heuch (2016) [28]

Australia

Funding: Not reported

Review question: what is the effectiveness of methods of offloading in preventing primary DFUs in adults with diabetes?

Diabetes mellitus, ≥18 years, no history of foot ulceration

All offloading methods and strategies to prevent foot ulcers

Alternative offloading methods; all other comparators, including traditional treatment by a podiatrist

All quantitative study designs, including RCTs, quasi-experimental studies, cohort studies, case-control studies, and descriptive studies including case series and before-and-after studies

Primary outcome: prevention of primary diabetic foot ulcers

Secondary outcome: indications of changes in pressure on the skin of the foot

0 RCTs

Healy (2013) [34]

UK

Funding: Not reported

To examine the effectiveness of footwear as an intervention for prevention of diabetic foot ulcers or the reduction of biomechanical risk factors for ulceration

Type I or type II diabetes mellitus, adults; ulceration risk not specified

Footwear as a preventive intervention

Alternative types of footwear

RCTs, quasi-experimental and observational studies with a control group or a repeated measure design

Ulceration/re-ulceration rates or biomechanical risk factors for ulceration (callus and plantar pressure measurement)

2 RCTs (Additional file 2: Supplementary references S5, S6) (n = 469)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

Paton (2011) [35]

UK

Funding: Not reported

To evaluate the effectiveness of insoles used for the prevention of ulcer in the neuropathic diabetic foot

Type I or type II diabetes mellitus, diagnosed with neuropathy, free from ulceration at study entry; ulceration risk not specified

Insoles

Not specified

RCTs, non-randomised control trials, follow-up/longitudinal studies

Primary outcome: time to ulceration

Other outcomes: pressure measurement, patient-based response/patient perception, cost

1 RCT (Additional file 2: Supplementary reference S5) (n = 69)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

Maciejewski (2004) [36]

USA

Funding: Department of Veterans Affairs (USA)

To review the evidence for the effectiveness of therapeutic footwear in preventing re-ulceration in people with diabetes and foot risk factors

Individuals with diabetes and foot risk factors

Off the shelf therapeutic shoes with custom or generic inserts or custom shoes with custom inserts; used with other interventions or footwear reimbursement as the primary intervention

Not specified

RCTs, non-randomised controlled trials, analytic studies, descriptive studies

Prevention of re-ulceration

2 RCTs (Additional file 2: Supplementary references S5, S6) (n = 469)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

Spencer (2000) [20]

UK

Funding: Cochrane review; no external sources of support

To assess the effectiveness of pressure relieving interventions in the prevention and treatment of diabetic foot ulcers

Type 1 or Type 2 diabetes mellitus, with (treatment trials) or without (prevention trials) foot ulcers; ulceration risk not specified

Relief or redistribution of pressure in the neuropathic and/or neuroischaemic diabetic foot e.g. callus removal, orthoses including insoles, bespoke and customised shoes and casts

Not specified

RCTs

Time to complete healing or proportion of ulcer(s) completely healed in trial time, healing rates, recurrence rates, new ulceration, complications and morbidity, patient satisfaction, quality of life, presence of callus, cost effectiveness, cost benefit

1 RCT (Additional file 2: Supplementary reference S5) (n = 69)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

Author (date) Funding

Objective

Evidence relevant to the overview

Population

Interventions

Comparators

Study designs

Outcomes

Hoogeveen (2015) [16]

Netherlands

Funding: Cochrane review; NIHR (UK) via Cochrane Wounds Group infrastructure funding

To assess the effectiveness of complex interventions in the prevention of foot ulcers in people with diabetes mellitus

Type 1 or type 2 diabetes mellitus, ≥18 years; ulceration risk not specified

Complex intervention defined as an integrated care approach, combining ≥2 prevention strategies on at least two different levels of care (patient, healthcare provider and/or structure of health care)

Any comparison including single interventions, usual care, and alternative complex interventions

RCTs

Primary outcomes incidence of foot ulceration; partial or total amputation rates

Secondary outcomes: callus development; resolution of callus; number and duration of hospital admissions for diabetes related foot problems; foot care knowledge scores; patients’ behaviour assessment scores; adverse events; costs

3 RCTs (Additional file 2: Supplementary references S12–S14)

n = 2455)

Ulcer risk: All levels Outcomes: ulceration; amputations

Narrative summary

Blanchette (2020) [39]

Canada

Funding: None

What is the effect of contact with a podiatrist and their interventions in an MDT context on LEA and DFU in people with diabetes?

Type 1 or type 2 diabetes mellitus, ≥18 years; ulceration risk not specified

Educational prevention, foot care, offloading, infection control, wound care and surgical strategies delivered by a podiatrist in a multidisciplinary context or MDT programme

Interventions or treatments without an MDT context

RCTs, prospective or retrospective cohorts, comparative cohorts before and after

Primary outcomes: DFU or LEA occurrence Secondary outcomes: mortality/survival, DFU or LEA reoccurrence, other complications (infection), healthcare utilization, patient satisfaction

0 RCTs

Mayfield (2000) [37]

USA

Funding: Not reported

To evaluate the evidence supporting the Semmes-Weinstein monofilament and other threshold testing in preventing ulcers and amputation in people with diabetes

People with diabetes; ulceration risk not specified

Semmes-Weinstein monofilament or another threshold neuropathy assessment method that could be conducted in a primary care setting

A reference standard of foot ulceration or amputation (for diagnostic evaluations)

Not specified

Ulceration, amputation

1 RCT (Additional file 2: Supplementary reference S13) (n = 1997)

Ulcer risk: all levels

Outcomes: ulceration; amputations

Narrative summary

Author (date) Funding

Objective

Author (date) Funding

Population

Interventions

Comparison

Study Designs

Outcomes

da Silva (2020) [43]

Brazil

Funding: Not Reported

Assess the effect of mobile technologies as a tool in diabetic foot prevention and diagnosis in people with diabetes mellitus

Type 1 or type 2 diabetes mellitus; ulceration risk not specified

Mobile technology aimed at diabetic foot prevention, foot self-care, or diagnosis

NS

NS

NS

0 RCTs

Hazenberg (2020) [42]

The Netherlands

Funding: Not Reported

To assess the psychometric properties, feasibility, effectiveness, costs, and current limitations of telehealth and telemedicine approaches for prevention and management of diabetic foot disease

Diabetes mellitus with or at risk of developing a foot ulcer (risk defined according to the IWGDF as having peripheral neuropathy, with or without foot deformities, peripheral artery disease or lower-extremity amputation and/or a history of foot ulceration)

Any telehealth or telemedicine application, or medical tool that may potentially serve as a telehealth or telemedicine application

NS

RCTs, non-randomised trials, case-control studies, cohort studies, cross-sectional studies, case series, case reports, qualitative research

Validity, reliability, feasibility, effectiveness, costs in the outcome categories of monitoring, prevention, or treatment of diabetic foot disease

4 RCTs (n = 524) (Additional file 2: Supplementary references S21–S23, S25)

Ulcer risk: High

Outcomes: ulceration

Analysis: Narrative summary

Ena (2021) [26]

Spain

Funding: None

To determine the effectiveness of the daily measurement of foot temperature in 6 points to prevent the occurrence of foot ulcers in patients with diabetes

Type 2 diabetes, at high risk of developing foot ulcers (history of neuropathy, deformity of the feet, or previous ulcer)

Twice daily monitoring of the temperature of the sole of the foot in 6 different locations along with the standard of care (use of insoles or orthopaedic footwear, education on diabetic foot prevention, routine foot care)

Standard of foot care (education, self-care practices, periodic clinical visits)

RCTs

Primary outcome: incidence of new foot ulcers (proportion of patients who developed a foot ulcer during follow-up)

4 RCTs (n = 524) (Additional file 2: Supplementary references S21–S23, S25)

Ulcer risk: High

Outcomes: ulceration

Analysis: meta analysis

Author (date) Funding

Objective

Author (date) Funding

Population

Intervention

Comparison

Study design

Outcome

Matos (2018) [44]

Portugal

Funding: NORTE2020, European Regional Development Fund

To analyse the effects of exercise and physical activity interventions on diabetic foot outcomes

A diagnosis of diabetes or diabetic peripheral neuropathy, polyneuropathy or DFU

Any form of supervised physical activity at home or a care centre

Daily life physical activity and/or usual foot care education

Controlled clinical trials

Diabetic foot outcomes

1 RCT (n = 79) (Additional file 2: Supplementary reference S24)

Ulcer risk: all levels

Outcomes: ulceration

Analysis: narrative summary

Author (date) Funding

Objective

Evidence relevant to the overview

Population

Interventions

Comparators

Study designs

Outcomes

Alahakoon (2020) [25]

Australia

Funding: James Cook University Strategic Research Investment Fund and other listed sources

Perform a systematic review and meta-analyses of RCTs of home foot temperature monitoring, education and offloading footwear for reducing the incidence of diabetes-related foot ulcers

Diabetes; IWGDF risk categories 2 or 3 without active diabetes-related foot ulcers

Home foot temperature monitoring, patient education, offloading footwear

Control group not receiving the intervention under study

RCTs

Primary outcome: DFU incidence (full thickness wound on the foot)

Secondary outcomes: minor, major and total amputations

17 RCTs (Additional file 2: Supplementary references S1–S10, S14, S19–S23, S25) (n = 2729)

Ulcer risk: High

Outcomes: ulceration, amputations

Analysis: Meta analysis

Arad (2011) [18]

USA

Funding: Not reported

To systematically assess RCTs regarding possible methods to prevent diabetic foot ulcers

People with diabetes, at risk of ulceration, with or without a history of previous foot ulcers

Primary and secondary prevention methods

Not specified

RCTs

Primary outcome: diabetic foot ulcers

9 RCTs (Additional file 2: Supplementary references S2, S5, S6, S9, S12, S13, S21–S23) (n = 3816)

Interventions: patient education (1 trial); footwear (3 trials); complex (2 trials); other (3 trials)

Ulcer risk: high

Outcomes: ulceration; amputations

Narrative summary

Crawford (2020) [14]

UK

Funding: Health

Technology Assessment

To systematically review data from RCTs of interventions used to prevent foot ulcerations in diabetes.

people of any age with a diagnosis of type 1 or type 2 diabetes, with or without a history of ulceration, but free from foot ulceration at trial entry.

Simple interventions (e.g. education aimed at individuals with diabetes or physicians, or the provision of footwear) and complex interventions.

Standard Care or active treatments

RCTs

Incident or recurrent foot ulcers; also sought data on amputation; mortality; gangrene; infection; adverse events; harms; time to ulceration; quality of life; timing of screening; self-care; hospital admissions; psychological; and adherence to therapy

22 RCTs (Additional file 2: Supplementary references S1–S15, S17, S21–S26) (n = 5410)

Outcomes:

ulceration, amputation

Ulcer risk: all levels

Analysis: meta analysis

Dy (2017) [41]

USA

Funding: AHRQ

To assess benefits and harms of interventions for preventing diabetic peripheral neuropathy complications and treatment of symptoms

Type 1 or type 2 diabetes; ≥18 years; at risk for peripheral polyneuropathy

Pharmacologic (glucose lowering) focused on glucose control; Nonpharmacologic (foot care, surgical interventions, dietary strategies, lifestyle interventions, exercise and balance training) and surgical

Active interventions, usual care/placebo

Systematic reviews, RCTs, non-randomised studies with concurrent comparison groups

Incident or recurrent foot ulcer, falls, perceived fall risk, amputation, HRQoL, physical activity level, harms

18 RCTs (n = 2778) (Additional file 2: Supplementary references S1, S3—S11, S14, S15, S17, S21–S25)

Ulcer risk: all levels

Outcomes: ulcer

Analysis: meta analysis.

O’Meara (2000) [19]

UK

Funding: Health Technology Assessment Board (UK)

To estimate the clinical and cost effectiveness of interventions for the prevention and treatment of diabetic foot ulcers

Diabetes mellitus, with a foot ulcer (treatment studies) or at risk of foot ulceration (prevention studies); ulceration risk not specified

Any intervention for the prevention and/or treatment of diabetic foot ulcers

Not specified

RCTs, non-RCTs with a contemporaneous control

Development or resolution of callus; incidence of ulceration; ulcer healing; ulcer recurrence rates; side effects; amputation rates

4 RCTs (Additional file 2: Supplementary references S5, S12, S13, S26) (n = 2622)

Interventions: footwear (1 trial); complex (2 trial); other (1 trial)

Ulcer risk: all levels

Outcomes: ulceration; amputations

Narrative summary

Mason (1999) [21]

UK

Funding: NHS Executive and British Diabetic Association

To evaluate the role of preventative strategies in reducing foot ulcers in patients with Type 2 diabetes mellitus, both in the general population and those identified to be at a raised risk

Type I or type II diabetes mellitus; ulceration risk not specified

Studies that addressed some aspect of screening, management, prevention or education relating to the foot care of people with diabetes

Not specified

RCTs, studies of lesser design

Not specified

3 RCTs (Additional file 2: Supplementary references S5, S12, S13) (n = 2462)

Ulcer risk: all levels Outcomes: ulceration; amputations

Narrative summary

Kaltenthaler (1998) [22]

UK

Funding: Not Reported

To review evidence on the effectiveness of interventions (including prevention) for diabetic foot ulcers

Diabetes; ulceration risk not specified

Prevention, multi-disciplinary education and support, treatments including topical applications, dressings, surgery, antibiosis, growth substances, hyperbaric oxygen, drug therapy, wound grafting, footwear and contact casts

Not specified

RCTs

Diabetic foot ulcers

2 RCTs (Additional file 2: Supplementary references S5, S12) (n = 464)

Ulcer risk: high

Outcomes: ulceration

Narrative summary

van Netten (2020) [30]

update of van Netten (2016) [31]

Netherlands

Funding: Not reported

To investigate the effectiveness of interventions to prevent first and recurrent foot ulcers in persons with diabetes who are at-risk for ulceration and do not have a current foot ulcer

Type I or type II diabetes mellitus, at risk of foot ulceration defined as presence of peripheral neuropathy, with or without a foot deformity or peripheral artery disease, or a history of foot ulcers or amputation of the foot or leg

Preventive interventions aimed at improvement in care, education of healthcare professionals, patient self- management, and medical interventions

Not specified

Systematic reviews, meta-analyses, RCTs, non-randomised controlled trials, case–control studies, controlled cohort studies, before-and-after studies, interrupted time series, prospective and retrospective non-controlled studies, cross-sectional studies, case series

Primary outcomes: first diabetic foot ulcer, recurrent diabetic foot ulcer

20 RCTs (Additional file 2: Supplementary references S1–S11, S14–S17, S21–S25) (n = 2968)

Outcomes: ulceration; amputations

Narrative summary