National Diabetes Foot Care Audit Report: 2014-2018
Source: data.gov.uk (2020-09-30)

National Diabetes Foot Care Audit 2014-2018. The National Diabetes Foot Care Audit (NDFA) is a continuous audit of diabetic foot disease in England and Wales. The audit enables all diabetes foot care services to measure their performance against NICE clinical guidelines and peer units, and to monitor adverse outcomes for people with diabetes who develop diabetic foot disease.

__Making clinical audit data transparent__

In his transparency and open data letter to Cabinet Ministers on 7 July 2011, the Prime Minister made a commitment to make clinical audit data available from the national audits within the National Clinical Audit and Patient Outcomes Programme.

__What information is being made available?__

Aggregated National Diabetes Foot Care Audit (NDFA) data for 2015-18 at NHS trust, specialist foot care service, sustainability and transformation partnership (STP), and clinical commissioning group (CCG) level.

__Measures about the process of care given to patients__

Information about care outcomes and treatment.

These data do not list individual patient information nor do they contain any patient identifiable data.

__Using and interpreting the data__

Data from the National Diabetes Foot Care Audit should not be looked at in isolation when assessing standards of care.

__Accessing the data__

The data are being made available on the data.gov website. Each year a data file from the National Diabetes Foot Care Audit will be made available in CSV format. Trusts and CCGs are identified by name and national code. Foot care services and STPs are identified by name and locally derived code.

__What does the data cover?__

The audit looks at the following areas:

* Structures: are the nationally recommended care structures in place for the management of diabetic foot disease?

* Processes: does the treatment of active diabetic foot disease comply with nationally recommended guidance?

* Outcomes: are the outcomes of diabetic foot disease optimised?

__What period does the data cover?__

This data covers patients first seen with a diabetic foot ulcer by a specialist foot service between 1 April 2015 and 31 March 2018. This National Report was published on 9 May 2019.

V1.1
9 May 2019
National Diabetes Foot Care Audit
Fourth Annual Report
England and Wales
01 April 2015 to 31 March 2018

Foreword
2
The National Diabetes Foot Care Audit (NDFA) was launched in July 2014 and this 4th
Annual Report summarises the findings derived from all foot ulcers registered up to March
2018 and followed for up to 6 months. The numbers registered each year are accelerating
and this is only because of the commitment of many, many staff. The total number of ulcers
now stands at well over 30,000.
The findings in the last 12 months have reinforced those of earlier years in confirming that
ulcers undergoing expert assessment within two weeks are less likely to be severe, more
likely to heal by 12 weeks, and less likely to lead to hospital admission and to amputation.
There are, however, quite large differences in clinical outcome in different areas and there is
now increasing evidence to link this variation with the structure of the local care pathway.
For the first time this year the total number registered has also allowed modelling to identify
those risk factors which link most closely to different clinical outcomes. In the future this will
allow the routine use of case-mix adjustment in comparing performance of different services.
By identifying aspects of the care pathway which link to variation between localities and
services, the aim is to improve clinical outcome for all people across England and Wales.
William Jeffcoate, Clinical Lead, NDFA

Contents
Section
Slide
Introduction
4
Recommendations
9
1
Participation and case ascertainment
12
2
Results
a. Care Structures
16
b. Outcomes
23
3
Associations
a. Care Structures
32
b. Time to first expert assessment
37
c. Modelling outcomes
42
4
Provider
variation
a. Risk-adjusted variation
49
b. Time to first expert assessment
58
Appendix: Modelling
63
Footnotes
80
Glossary
86
Further information
101
3
Acronyms
The following acronyms and
abbreviations are used throughout
the report and are not always
defined on the slide:
FPS = Foot Protection Service
MDFT = Multi-disciplinary Foot
Care Team
NDA = National Diabetes Audit
NDFA = National Diabetes Foot
Care Audit
NICE = The National Institute for
Health and Care Excellence
QIC = Quality Improvement
Collaborative
RRT = Renal replacement therapy

Introduction: Aims and background
•
The National Diabetes Foot Care Audit (NDFA) measures
the outcomes and treatment structures/processes for
newly occurring foot ulcers affecting people with diabetes.
•
The aim is to determine variation in clinical outcomes
across England and Wales and the extent to which they
can be explained by differences in aspects of care.
•
The NDFA is part of the National Diabetes Audit (NDA)
portfolio within the National Clinical Audit and Patient
Outcomes Programme (NCAPOP), commissioned by the
Healthcare Quality Improvement Partnership (HQIP).
•
The NDFA started in July 2014; previous reports were
published in March 2016, March 2017, October 2017 and
March 2018.
4
Prepared in collaboration with:
Supported by:

Introduction: Why is this audit important?
Findings and recommendations in this report support the audit questions:
5
2.
Processes: Does treatment of active diabetic foot disease comply
with national recommended guidelines?
3.
Outcomes: Are the outcomes of diabetic foot disease optimised?
1.
Structures: Are NICE-recommended care structures in place for the
management of diabetic foot disease?
• In 2014-15 the annual cost of diabetic foot disease to the NHS in England was estimated
at around £1 billion, approximately 1% of the total NHS budget, in addition to the
personal/social costs of reduced mobility and sickness absence.
• More than 64,000 people with diabetes in England and Wales are thought to have foot
ulcers at any given time (derived from Kerr 2017).
• Treatment for diabetic foot disease may involve amputation. There are around 7,000
minor (below the ankle) and major (above the ankle) amputations in people with diabetes
in England each year.
• Only around three in five people with diabetes who have had a diabetic foot ulcer survive
for five years, dropping to half for those having a major amputation.

Introduction: Patient perspective
6
Everyone involved in the care of people with diabetes should strive
to address the concerns raised by our patient representatives.
It is hoped that this report will be an important part of this process.
NDFA team
People living with diabetes should be confident that foot care services
can provide early diagnosis and effective treatment of foot problems
to give the best possible outcome. It is unacceptable that the care you
can expect to receive can be dependent on where you live.
It is also important for services to work closely with people with
diabetes to prevent foot disease. The cost to the NHS of diabetes
care is headline news, but improvement of foot care services has
shown that the financial and human cost can be reduced.
NDFA patient representatives, 2019

Introduction: Quality improvement
7
•
Reducing the interval to the first expert assessment
•
Reducing the severity of ulcers
•
Reducing emergency admissions
•
Reducing amputations and other
complications
•
Upskilling the wider team
•
Improving the care pathways
21 NHS provider organisations across England and Wales are participating, with each
service developing a tailored improvement plan to address local needs. The collaborative
is developing quality improvement work around the following diabetes footcare topics:
A report on the improvements
made and lessons learned will
be produced at the end of the
NDFA Quality Improvement
Collaborative (QIC) year.
A Quality Improvement Collaborative (QIC) has been incorporated into the
NDFA programme for 2018/19 with the aim of focusing on improvement
activity. The power of this approach is in the collaboration between teams,
sharing ideas of how they are undertaking their projects, what they learn and
how they can implement changes.

Introduction: Analysis in 4th Annual Report 2019
8
Updated figures on…
New analyses of…
Cohort: The NDFA Fourth Annual Report covers patients in England and Wales with ulcers that
underwent first expert assessment by a specialist foot care service between April 2015 and March 2018.
Data from July 2014 onwards was used to build the models for the casemix adjustment.
Caseload estimates provided by NDFA
submitters.
Deaths within 6 months.
A new provider survey of six key care
structures, with comparisons to the earlier
commissioner survey.
Risk-adjusted outcomes at area/provider
level for four key clinical outcomes:
•
Alive and ulcer free
•
Foot disease-related admissions
•
Major amputation (above the ankle)
•
Mortality
The following clinical outcomes:
1)
Being alive and ulcer free at 12 weeks.
2)
Having a foot disease-related admission within 6 months.
3)
Having a major amputation (above the ankle) within 6
months.
Associations between clinical outcomes and:
•
Patient demographics e.g. age, sex, smoking status.
•
Health factors e.g. hospital admission for heart failure.
•
Ulcer characteristics e.g. SINBAD elements, ulcer
severity, Charcot disease.
•
Care processes and structures of care e.g. time to first
expert assessment, NICE recommendations.

Recommendations
For the NDFA fourth Annual Report
9
National Diabetes Foot Care Audit
Fourth Annual Report

Recommendations: People with diabetes
10
For people with diabetes
•
If you have poor circulation (peripheral artery disease or ischaemia) or experience loss of
feeling (neuropathy), seek advice from your GP or usual diabetes carer about how to
prevent foot ulcers.
•
If you get a new foot ulcer, seek quick referral from a healthcare professional, to a local
specialist diabetes foot care service.
The following resources will provide you with further information to help with managing your feet:
•
Taking care of your feet: https://www.diabetes.org.uk/Guide-to-
diabetes/Complications/Feet/Taking-care-of-your-feet/
•
Tips for everyday foot care: https://www.diabetes.org.uk/Guide-to-
diabetes/Complications/Feet/Taking-care-of-your-feet#Annual
•
Diabetes and foot problems: https://www.diabetes.org.uk/Guide-to-diabetes/
Complications/Feet/
•
The ‘Putting Feet First’ campaign: https://www.diabetes.org.uk/get_involved/
campaigning/putting-feet-first

Recommendations:
For healthcare professionals and commissioners
11
Notes: 1. The NICE guidelines for Diabetic foot problems: prevention and management http://www.nice.org.uk/guidance/ng19.
For healthcare professionals
Including podiatrists, diabetes specialist
nurses, diabetes consultants and any
healthcare professional that works with
people with diabetes.
•
Use the audit findings to encourage
commissioners and service managers to
ensure a NICE-recommended diabetes
foot care service is in place1.
•
Create simple and rapid referral
pathways.
•
Participate in the NDFA to collaborate in
this nationwide drive to improve the
outcomes for diabetic foot disease.
For commissioners
•
Work with providers to ensure that in
every locality the NICE-
recommended diabetic foot care
structures are implemented1 and
that the delivery of care is effectively
integrated between all those
involved.
•
Ensure that your local diabetes
specialist foot care services
participate in the NDFA so that
measurement of care processes and
outcomes can support continuous
quality improvement in all services.

1. Participation and case ascertainment
Results and Findings
12
National Diabetes Foot Care Audit
Fourth Annual Report

Audit questions:
•
Participation: How many providers participate in
the NDFA?
•
Case ascertainment: What proportion of people
with diabetic foot ulcers are recorded in the NDFA?
1. Participation and Case Ascertainment:
Overview
Key findings
•
221 specialist foot care services
have submitted 33,155 ulcer
episodes to NDFA since April
2015.
•
Annual submissions have almost
doubled in the last three years
(from 7,965 to 15,370), with case
ascertainment rising from
approximately 10 to 20 per cent.
13
How is NDFA case ascertainment assessed?
The numerator is the number of people with foot ulcers
submitted to the audit.
The exact number of people with foot ulcers in England and Wales is not known. Therefore the
denominator is estimated from various sources:
a)
Annual caseload estimates provided by NDFA submitters, collected for the first time in 2018.
b)
Estimates derived from Abbott et al (2002) and Kerr (2017), which indicate that more than 64,000
people with diabetes in England and Wales have a foot ulcer at any given time.
c)
Comparison of the number of amputations reported in NDFA (patients with new foot ulcers)
and NDA (all patients with diabetes).

1. Participation and Case Ascertainment:
Foot care providers
14
143 providers
• 136 NHS trusts in England and
7 Local Health Boards (LHBs) in Wales
221 services
• 203 specialist foot care services
in England and 18 in Wales
27,700 patients
with 33,155
ulcer episodes
• With first expert assessment between
01 April 2015 and 31 March 20181
Figure 1.1: Participation in the NDFA process
and outcomes collection, England and Wales, 2015-18
In 2017-18:
14,120 patients
15,370 episodes
In 2016-17:
9,095 patients
9,815 episodes
In 2015-16:
7,390 patients
7,965 episodes
Based on annual caseload
estimates provided by
NDFA submitters, case
ascertainment in 2017-18 is
approximately 20 per cent.
Notes: 1. An additional
5,325 episodes were
submitted between July
2014 and March 2015.
2. All values have been
rounded. Values between
1 and 7 are represented
as a 5. All values greater
than 7 have been rounded
to the nearest five.
i

1. Participation and Case Ascertainment:
Commentary
15
NDFA team
The NDFA team would like to thank all the teams who have worked hard to
contribute to this unique and valuable insight into the care and outcomes of
people with diabetic foot ulcers.
It is reassuring that case ascertainment is continuing to rise, almost doubling from
2015-16 to 2017-18. Teams should continue to work to make sure this improvement
continues, ensuring comprehensive coverage in future years.
Recommendations
Healthcare professionals: Participate in the NDFA to collaborate in this
nationwide drive to improve the outcomes for diabetic foot disease.
Commissioners: Ensure that your local diabetes specialist foot care services
participate in the NDFA so that measurement of care processes and
outcomes can support continuous quality improvement in all services.

2a. Results: Care structures
Results and findings
16
National Diabetes Foot Care Audit
Fourth Annual Report

2a. Results: Care structures
Commissioner and provider surveys
This year, we asked…
In 2015-17, we asked…
The audit conducts surveys of structures of care relevant to people with diabetic foot disease.
Clinical Commissioning Groups
and Local Health Boards
about
care structures they
commissioned.
•
Routine foot examination training
•
Foot Protection Service (FPS)
•
Urgent referral pathway6
NHS Trusts, Local Health Boards and
Independent Healthcare Providers
about
care structures they provided.
•
Routine foot examination training
•
Foot Protection Service (FPS)
•
Urgent referral pathway6
•
Step-down protocol between MDFT and FPS
•
Urgent vascular assessment
•
Vascular service discussion time
6
3
17
Notes: 6. Please refer to list of footnotes in the Footnote section.
Please see Glossary for explanation of terms.
i

2a. Results: Care structures
Overview
Audit questions: Providers were asked to
complete a survey of the following care structures
in place for the management of diabetic foot
disease:
1.
Training for routine diabetic foot
examinations3.
2.
An established Foot Protection Service
(FPS) pathway4.
3.
An established pathway for new referrals - if
needed - for an assessment within 24
hours5.
4.
Step-down or shared care between the Multi-
Disciplinary Foot Team and the FPS.
5.
Urgent vascular assessment within 24 hours.
6.
Time dedicated to discuss patients with
vascular services.
Key findings
•
Less than a third (31 per cent) of participating
providers reported that all six care structures
were in place.
•
9 in 10 providers had a Foot Protection
Service pathway in place.
•
Almost half of providers did not report having a
pathway in place for the assessment of urgent
referrals within 24 hours (46 per cent).
Notes: 3, 4, 5. Please refer to list of footnotes in the Footnote section.
Please see Glossary for explanation of terms.
18
Participation
•
108 of 143 NDFA providers (76 per cent)
participated in the 2018 NDFA Provider Survey. A
further 2 providers responded, making 110
participants in total.
•
Of the 108 NDFA provider participants, 90
represented all services in their area, with the
remainder representing only some local services.
i

2a. Results: Care structures
Why are care structures important?
19
2018 NDFA ‘Success Factors’
Survey
The ten services in the Third Annual
NDFA report (2018) with the highest
proportion of severe (SINBAD 3+) ulcer
patients that were alive and ulcer free at
12 weeks were asked to identify factors
they thought contributed to their relative
success. All 10 services responded. The
factors suggested by a high proportion of
these services are shown on the right:
All 10 services reported:
•
Direct access to a Multi-disciplinary Foot
Care Team (MDFT).
•
Good community podiatry/MDFT
integration.
At least 80% of services reported:
•
Fuss free referrals accepted from any
healthcare professional or patient.
•
Option for next working day appointments.
•
Prompt access to a vascular service.
Optimised structures and pathways of care are necessary to achieve the best
outcomes for people with diabetic foot ulcers. Without this care infrastructure it
is not possible to treat diabetic foot disease efficiently and effectively.
i

Notes: Participating responders (those that
completed the 2018 NDFA Provider Survey
and entered ulcer episodes in 2015-18) are
included in this analysis if they responded
“yes” or “no” to each of the six survey
questions about their care structures (76 per
cent of all the organisations that responded
to the 2018 NDFA Provider Survey).
20
Figure 2.1: Per cent of providers with care structures in place: number of structures
Providers, England and Wales, 2018
2a. Results: Care structures
2018 NDFA Provider Survey responses
Key findings
Less than a third (31 per cent) of
participating providers reported
that all six care structures were in
place.
i

Almost half
of providers
had no
urgent referral
pathway
21
Figure 2.2: Per cent of providers with care structures in place,
Providers, England and Wales, 2018
2a. Results: Care structures
Care structures missing
9 in 10
providers had a
Foot Protection
Service in place
53.7
66.7
69.4
72.2
88.9
90.7
0
20
40
60
80
100
Urgent referral pathway
Vascular service discussion time
Urgent vascular assessment
Routine foot examination training
Step-down protocol between MDFT and FPS
Foot Protection Service (FPS)
Per cent of providers that confirmed care structure
Care structure
i

2a. Results: Care structures
Commentary
Recommendations
All those responsible for commissioning footcare services in
England and Wales should:
1.
Work with providers to ensure that in every locality these
diabetic foot care structures are implemented and that
the delivery of care is effectively integrated between all
those involved.
2.
Have a Foot Protection Service (FPS) which has primary
responsibility for the care of people at high risk of new
ulceration. The FPS will work in close liaison with
specialist services for the care of established ulcers with
particular accent on ‘step-up’ and ‘step-down’ care.
3.
Provide education for non-specialist healthcare
professionals, who play a key role in the delivery of
diabetes care.
22
NDFA team
Optimised structures and pathways of
care are necessary to achieve the best
outcomes for people with diabetic foot
ulcers. Without this care infrastructure it
is not possible to treat diabetic foot
disease efficiently and effectively.
The findings of the 2018 NDFA ‘Success
Factors’ Survey (see Slide 19) confirm
the importance of efficient care structures
in achieving successful outcomes for
people with diabetic foot ulcers.
However, only one third of participating
providers confirmed that all six care
structures are in place, with only half of
providers having an urgent referral
pathway.
i

2b. Results: Outcomes
Results and findings
23
National Diabetes Foot Care Audit
Fourth Annual Report

Audit questions: What are the
outcomes for people with diabetic foot ulcers?
• How many are alive and ulcer free after
twelve weeks of their first assessment?
• How many patients have a major
amputation (above the ankle) within six
months?
• How long do patients stay in hospital with
conditions related to diabetic foot disease?
• How likely is it that a patient with a diabetic
foot ulcer will have died within one year?
How does ulcer severity affect outcomes?
New analysis: For the first time, mortality
data have been traced from the Office for
National statistics for all NDFA patients seen
from 1 April 2017 onwards, allowing survival
curves to be produced.
2b. Results: Outcomes
Overview
Key findings
Alive and Ulcer Free
One third of patients with severe ulcers (SINBAD 3+)
were alive and ulcer free at 12 weeks (35 per cent).
Major amputation (above the ankle)
In the 6 months after first expert assessment 3 per cent
of patients with severe ulcers had a major amputation.
Foot disease admission
One in three patients with severe ulcers had a foot
disease-related admission within 6 months of their first
expert assessment. The median length of stay for each
admission varied between 7 and 12 days in networks.
Mortality
1 in 10 patients died within 1 year of first expert
assessment. Death rates for people with severe
ulcers were almost twice those of people
with less severe ulcers (SINBAD 0-2).
24
i

2b. Results: Outcomes
Alive and ulcer free
12 week
outcome
All ulcers
Less severe ulcer
SINBAD 0-2
Severe ulcer
SINBAD 3+
(33,155 episodes)
(18,365 episodes)
(14,790 episodes)
Number
Per cent8
Number
Per cent8
Number
Per cent8
Alive and
ulcer-free2
14,520
48.7
9,850
59.9
*
4,675
34.9
*
Persistent
ulceration
14,400
48.3
6,215
37.8
*
8,185
61.1
*
Deceased16
915
3.1
375
2.3
*
540
4.0
*
Lost to
follow up7
2,010
-
1,215
-
z
795
-
z
Unknown7
1,305
-
705
-
z
600
-
z
* = statistically significant at the 0.05 level (Less severe vs Severe).
n = not statistically significant (Less severe vs Severe). z = not applicable. Not used in cohort.
Less than
half
of all ulcers
were
healed at
12 weeks
(49 per cent)
Only one third
of severe
ulcers were
healed at 12
weeks
(35 per cent)
Table 2.1: Alive and ulcer-free2 at 12 weeks, by ulcer severity,
England and Wales, 2015-18 (rounded1)
25
Notes: 1, 2, 7, 8, 16. Please refer to list of footnotes in the Footnote section.
Please see Glossary for explanation of terms.
i

26
2b. Results: Outcomes
Major amputations
Table 2.2: Major amputations within 6 months of first expert assessment,
England and Wales, 2015-189 (rounded1)
Severe ulcers are four times
as likely to lead to major
amputation (above the ankle)
than less severe ulcers.
Notes: 1, 9. Please refer to list of
footnotes in the Footnote section.
Please see Glossary for
explanation of terms.
Patient having…
All ulcers
(24,200 patients)
Less severe ulcer
SINBAD 0-2
(13,210 patients)
Severe ulcer
SINBAD 3+
(10,995 patients)
Number
Per cent
Number
Per cent
Number
Per cent
One or more
major amputation
(above the ankle)
385
1.6
90
0.7
*
295
2.7
*
* = statistically significant at the 0.05 level (Less severe vs Severe). n = not statistically significant
24,200
patients
assessed
385 had
major
ampu-
tation
Within 6
months
i

2b. Results: Outcomes
Foot disease-related admissions
27
Table 2.3: Foot disease-related admissions10 within 6 months of first expert
assessment: length of stay12, by ulcer severity, by network England and Wales, 2015-189 (rounded1)
Notes: 1, 9, 10, 11, 12. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
Ulcer
severity
Number
of
patients
Number of
hospital
admissions
Number
of bed
days11
Length of stay12
Median
Mean
Less severe (SINBAD 0-2)
1,540
2,205
22,255
8.0
13.7
Severe (SINBAD 3+)
3,690
6,230
71,370
10.0
16.3
All ulcers
5,230
8,435
93,625
9.0
15.6
NDFA patients had over
90,000 hospital bed days
related to foot disease
within 6 months
Three quarters of
bed days were for
patients with severe
ulcers
Context
NDFA case
ascertainment of
10-20 per cent
means that the total
number of bed days
across the NHS
could be 5 to 10
times that reported
in the audit.
i

Patients with
severe
ulcers were
almost twice
as likely to die
within 1 year
28
2b. Results: Outcomes
Mortality
Table 2.4: Deaths after first expert assessment17, by ulcer severity,
England and Wales, 2017-1813 (rounded1)
Mortality17
within …
Number
of ulcers
Number
of
patients
Traced15 patients
Deceased patients
Number
Per cent
Number
Per cent
12 weeks
15,370
14,120
14,070
99.6
505
3.6
24 weeks
14,615
13,475
13,430
99.7
875
6.5
1 year
5,355
5,165
5,150
99.7
525
10.2
Mortality17
within …
Traced
patients14,15
Less severe
SINBAD 0-2
Deceased patients
Traced
patients14,15
Severe
SINBAD 3+
Deceased patients
Number
Per cent
Number
Per cent
12 weeks
8,015
210
2.6
6,475
300
4.6
24 weeks
7,635
360
4.7
6,165
525
8.5
1 year
2,860
205
7.2
2,345
325
13.9
Notes: 1, 13, 14, 15, 17. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
1 in 10
patients die
within 1 year
of expert
assessment
i

2b. Results: Outcomes
Survival curve by ulcer severity
Figure 2.3: Survival curve from date of first expert assessment, by ulcer severity,
England and Wales, 2017-1813, 17
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0
30
60
90
120
150
180
210
240
270
300
330
360
Cumulative survival
Days after first expert assessment
Severe (SINBAD 3+)
Less severe (SINBAD 0-2)
29
Notes: 13, 17. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
i

2b. Results: Outcomes
Survival curve by SINBAD element
30
Figure 2.4: Survival curve from date of first expert assessment, by SINBAD element,
England and Wales, 2017-1813, 17
0%
20%
40%
60%
80%
100%
Ischaemia (poor circulation)
No Ischaemia
0%
20%
40%
60%
80%
100%
Neuropathy (loss of feeling)
No Neuropathy
0%
20%
40%
60%
80%
100%
0
365
Days
Bacterial Infection
No Bacterial Infection
0%
20%
40%
60%
80%
100%
0
365
Days
Area ≥ 1 cm²
Area < 1cm²
0%
20%
40%
60%
80%
100%
0
365
Days
Depth (to tendon or bone)
Not to tendon or bone
0%
20%
40%
60%
80%
100%
Site (on hindfoot)
Not on hindfoot
Notes: 13, 17. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
i

2b. Results: Outcomes
Commentary
Recommendations
To minimise the severity of diabetic foot ulcers at first
expert assessment:
Patients with poor circulation (peripheral artery
disease or ischaemia) or loss of feeling (neuropathy)
should seek advice from their GP or usual diabetes
carer about how to prevent foot ulcers.
Patients with new foot ulcers should seek quick
referral from a healthcare professional to a local
specialist diabetes foot care service.
Providers should ensure that people with diabetic foot
ulcers are referred promptly for early specialist
assessment, in line with NICE guidance.
Commissioners should ensure that NICE-
recommended structures of care are in place.31
NDFA team
The audit has consistently found
that ulcer severity is strongly
associated with worse patient
outcomes, including:
•
Lower healing rates.
•
More/longer hospital admissions.
•
Higher major amputation rates
(above the ankle).
•
Higher mortality rates.
The NDFA survival curves show that
1 in 7 people with severe ulcers die
within one year of assessment,
rising to almost 1 in 4 for those with
ischaemia.
i

3a. Associations: Care structures
Results and findings
32
National Diabetes Foot Care Audit
Fourth Annual Report

Key findings
Associations were found between care structures and:
•
Faster assessment
•
Improved rates of healing
3a. Associations: Care structures
Overview
33
Audit questions: Are different care
structures associated with care processes
(time for patients to reach specialist
assessment) and outcomes (being alive
and ulcer free)?
How is this measured? Aspects of
each assessment (including outcomes)
were linked to the care – structures
reported by their foot care service
provider.
Why is this important?
Although causation cannot be proven,
consistent associations between care
structures and outcomes may help inform
organisations about how to manage their
diabetic foot-care services more
effectively.
Associations
With care structure
Routine foot
examination
training
Foot Protection
Service (FPS)
Urgent referral
pathway
Step-down
protocol
between MDFT
and FPS
Shorter waits (<2 weeks)
▲
▲
▲
▲
Longer waits (>2 months)
▲
▲
▼
▲
Being alive and ulcer free at 12 weeks:
… less severe ulcers (SINBAD 0-2)
■
▲
▲
▲
… severe ulcers (SINBAD 3+)
■
■
▲
▲
Better outcomes where care structure is present
▲
Poorer outcomes where care structure is present
▼
Outcome unchanged where care structure is present
■
i

3a. Associations: Care structures
vs time to first expert assessment
Table 3.1: Time to first expert assessment, by provision of care structures
England and Wales, 2015-18 (rounded1)
Process:
Time to
assessment
Per cent of ulcers at providers with the following care structures…
Routine foot
examination training3
Foot Protection
Service (FPS)4
Urgent referral
pathway5, 6
Step-down protocol
between MDFT / FPS
% Yes
% No
%
% No
% Yes
% No
% Yes
% No
Self-referred
30.9
14.6
*
29.4
15.6
*
26.6
26.0
n
29.4
12.7
*
< 2 weeks7
66.6
61.0
*
64.5
52.9
*
64.4
59.3
*
64.6
50.0
*
> 2 months7
9.0
11.1
*
10.5
14.8
*
12.3
9.5
*
10.4
15.9
*
34
* = statistically significant at the 0.05 level (Yes vs No). n = not statistically significant
•
Being seen in less than 2 weeks is
associated with all four care structures
•
Self-referral is associated with all care
structures except urgent referral
pathway
•
Being seen after more than
2 months is associated with
providers having an urgent
referral pathway.
Notes: 1, 3, 4, 5, 6, 7. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
i

3a. Associations: Care structures
vs alive and ulcer free
Table 3.2: Alive and ulcer free2 at 12 weeks, by provision of care structures
England and Wales, 2015-18 (rounded1)
Outcome:
Alive and ulcer
free at 12 weeks
Per cent of ulcers at providers with the following care structures…
Routine foot
examination training3
Foot Protection
Service (FPS)4
Urgent referral
pathway5, 6
Step-down protocol
between MDFT / FPS
% Yes
% No
% Yes
% No
% Yes
% No
% Yes
% No
… less severe ulcers
… (SINBAD 0-2)
59.3
57.7
n
59.6
55.8
*
60.8
56.6
*
60.0
52.1
*
… severe ulcers …
… (SINBAD 3+)
34.2
35.1
n
34.9
32.5
n
35.8
33.5
*
35.1
31.0
*
* = statistically significant at the 0.05 level (Yes vs No). n = not statistically significant
Notes: 1, 2, 3, 4, 5, 6. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.
i
Patients with less severe or severe ulcers are
more likely to be alive and ulcer free at 12
weeks, where the provider has:
•
Urgent referral pathway
•
Step-down care between MDFT and FPS
Patients with less severe ulcers only are
more likely to be alive and ulcer free at 12
weeks, where the provider has:
•
Foot Protection Service
35

3a. Associations: Care structures
Commentary
36
NDFA team
Where care structures are not available, referral times
are longer and clinical outcomes are worse.
However, the NDFA has already found that many
providers are missing one or more of these key care
structures (see Slide 21). There is appreciable
concordance between the NDFA ‘Success Factors’
Survey (Slide 19) and the care structures audit.
Commissioners and providers should therefore focus on
ensuring that every person with diabetes has access to all
recommended diabetic foot ulcer care structures.
Recommendations
All those responsible for commissioning footcare services
should ensure that:
•
A system of training is available for all healthcare
professionals undertaking routine foot screening in diabetes.
•
A pathway is established so that all people with diabetes
who are at increased risk of foot ulceration can – where
needed – receive from a Foot Protection Service (FPS):
o
Further assessment
o
Surveillance
o
Protective care
The FPS should work in close liaison with specialist services
for the care of established ulcers with particular accent on
‘step-up’ and ‘step-down’ care.
•
A clear pathway exists to ensure that people with new
diabetic foot ulcers can be referred – according to NICE
guidance – within one working day for expert assessment.
“People living with diabetes must be able to be
confident that, locally, there are foot care services
that they can rely on [and] that the best treatment
is available at all stages of diabetic foot disease
to ensure the best possible outcomes.”
NDFA patient representatives, 2018
i

3b. Associations: Time to first expert
assessment
Results and findings
37
National Diabetes Foot Care Audit
Fourth Annual Report

Key findings
•
When time to assessment
is 14+ days there are
worse outcomes at 12
weeks.
•
Self-referred ulcers are
more likely to be healed at
12 weeks.
•
Ulcers seen with time to
expert assessment >2
months are most likely to
be severe.
•
There is little difference
between the proportions of
severe ulcers in the ≤ 2
month groups.
3b. Associations: Time to first expert assessment
Overview
38
Audit question:
Does the length of time to first expert assessment have an
association with ulcer severity at presentation, and with being
alive and ulcer free at 12 weeks?
How is this measured? For each ulcer, the interval from
initial presentation to a health professional to first assessment
by a specialist who assumes care of the foot is recorded.
NICE guidance: People with diabetes who have an active
foot problem should be referred to a specialist team within
one working day for triage within one further working day5.
Why is this important? A relationship between longer times
to first expert assessment and severe ulceration (SINBAD 3+)
emphasises the importance of ensuring prompt referral for
specialist assessment – a linchpin of the NICE guidance5.
Notes: 5. Please refer to list of footnotes in the footnote section.

3b. Associations: Time to first expert assessment
vs Alive and ulcer free
39
Figure 3.1: Alive and ulcer-free2 at 12 weeks, by time
to first expert assessment, England and Wales, 2015-18
(rounded1)
A time to
assessment of
14+ days
results in worse
outcomes at 12
weeks
54.5*
48.2ⁿ
49.0ᶻ
44.9*
35.4*
0
10
20
30
40
50
60
Self-referred
≤ 2 days
3-13 days
14 days - 2 months
> 2 months
12 weeks
Percentage alive and ulcer-free
... time to first expert assessment
Context: People that self-refer
have usually had a previous foot
ulcer and know the foot care team, or
may have been identified as high-risk
and attend a foot protection service.
Most people cannot refer themselves
directly to a specialist foot care
service and must be referred.
* = statistically significant at the 0.05 level (vs 3-13 days).
n = not statistically significant (vs 3-13 days). z = not applicable. Used as comparison group.
Notes: 1, 2. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.

There is little
difference in the
proportion of
severe ulcers in
the ≤ 2 month
groups
Between 46.7 and 49.1 per cent,
excluding self-referrers
3b. Associations: Time to first expert assessment
vs Ulcer severity
40
Figure 3.2: Time to first expert assessment,
by ulcer severity, England and Wales, 2015-18 (rounded1)
46.0
52.2
53.3
50.9
64.5
54.0
47.8
46.7
49.1
35.5
0
20
40
60
80
100
> 2 months*
14 days - 2 months
3-13 days
≤ 2 days*
Self-referred*
Prevalence of ulcer severity within interval group (%)
Less severe ulcer
Severe ulcer
n
z
Ulcers seen with time
to expert assessment
>2 months are
most likely to be
severe (SINBAD 3+)
54 per cent vs. 35 to 49 per cent
* = statistically significant at the 0.05 level (vs 3-13 days).
n = not statistically significant (vs 3-13 days). z = not applicable. Used as comparison group.
Notes: 1. Please refer to list of footnotes in the Footnote section. Please see Glossary for explanation of terms.

3b. Associations: Time to first expert assessment
Commentary
Recommendation
All people with diabetic foot ulcers
should be referred promptly for early
specialist assessment, in line with
NICE guidance5.
41
NDFA team
The evidence derived from over 33,000 new diabetic foot ulcers suggests
that early referral is associated with better outcomes at 12 weeks; ulcer
severity is higher amongst those that wait the longest.
Notes: 5. Please refer to list of footnotes in the Footnote section.
Please see Glossary for explanation of terms.

3c. Associations: Modelling
Results and findings
42
National Diabetes Foot Care Audit
Fourth Annual Report

3c. Associations: Modelling
Overview
43
43
Audit question: What patient and ulcer
characteristics are associated with the following
outcomes, measured from date of first expert
assessment?
•
Being alive and ulcer free2 at 12 weeks.
•
Having a foot disease-related admission
within 6 months.
•
Having a major amputation of the lower limb
(above the ankle) within 6 months.
•
Death within 6 months10,11 (6 month mortality).
Why is this important? The above outcomes
are key indicators of clinical performance across
organisations. By identifying the characteristics
associated with these outcomes, risk-adjusted
outcomes can be produced which account for
differences in the ‘casemix’ of patients seen at each
organisation.
Key findings
•
Models were strongest for ‘6 month mortality’
and ‘major amputation’ (above the ankle). The
model for ‘alive and ulcer free’ was the weakest,
meaning that much of the variation is unexplained
by the selected variables.
•
Ulcer characteristics are much more strongly
associated than other factors with ‘alive and ulcer
free’ and ‘major amputation’ but demographic
factors were more important for ‘6 month
mortality’.
•
Of the ulcer characteristics, ischaemia (poor
circulation) has the strongest associations with
patient outcomes.
•
Time to first expert assessment is associated
with being ‘alive and ulcer free’ and ‘foot disease-
related admissions’, but not with
‘major amputation’ or ‘6 month mortality’.
\
Notes: 2, 10, 11. Please refer to list of footnotes in the Footnote section.
i

3c. Associations: Modelling
Alive and ulcer free2: Summary
Which variables were selected? 15 variables had consistent associations with the
outcome, including time to first expert assessment and all 8 ulcer characteristics.
How strong is the model? The model strength is just below reasonable.
Which variables had the strongest associations? Ulcer factors have much
stronger associations than other variable types (see below left).
Ulcer
factors
Patient
Health
Processes
Estimated
contribution8,9
Estimated
contribution8
Worse outcomes are most-strongly associated with:
• All six SINBAD elements, particularly ischaemia (poor
circulation) and having a large ulcer (see chart on right),
inactive Charcot and multiple ulcers.
• Waiting over 2 months for first expert assessment.
• Admissions for myocardial infarction, renal replacement
therapy or heart failure.
• Having diabetes for ≥10 years, being current smoker or male.
Better outcomes are most-strongly associated with:
• Single ulcers and being female.
Developed
using data on
27,140 ulcers1
Notes: 1, 2, 8, 9. Please refer to list of footnotes in the Footnote section.

3c. Associations: Modelling
Foot disease admission: Summary
Which variables were selected? 12 variables had consistent associations with the
outcome, 11 of which were also selected for the alive and ulcer free model.
How strong is the model? The model strength is reasonable (c-statistic = 0.74).
Which variables had the strongest associations? Ulcer factors have much
stronger associations than other variable types (see below left).
Ulcer
factors
Patient
Health
Processes
An increased number of admissions are most-strongly
associated with:
• All SINBAD elements except hindfoot ulceration, including
the four strongest associations (see right).
• Having first expert assessment within 2 days.
• Hospital admissions for heart failure or renal replacement
therapy.
• Having diabetes for ≥20 years.
A decreased number of admissions are most-strongly
associated with being female and being aged 65 or above.
Developed
using data on
26,705 ulcers1
Estimated
contribution8,9
Estimated
contribution5
Notes: 1, 8, 9. Please refer to list of footnotes in the Footnote section.

3c. Associations: Modelling
Major amputation: Summary
Which variables were selected? 9 variables had consistent associations with the
outcome, including 6 ulcer characteristics.
How strong is the model? The model strength close to strong (c-statistic = 0.79).
Which variables had the strongest associations? Ulcer factors have much
stronger associations than other variable types (see below left).
Ulcer
factors
Patient
Health
Higher rates of major amputation (above the ankle) are most-
strongly associated with:
• Ischaemia (poor circulation) has by far the strongest
association, followed by having a large ulcer.
• Other associated ulcer factors are hindfoot ulceration and
Charcot.
• Hospital admissions for renal replacement therapy.
• Being a current smoker.
Lower rates are most-strongly associated with:
• Being aged 80 or above.
Developed
using data on
26,705 ulcers1
Estimated
contribution8,9
Estimated
contribution5
Notes: 1, 8, 9. Please refer to list of footnotes in the Footnote section.

3c. Associations: Modelling
6 month mortality: Summary
Which variables were selected? 9 variables had consistent associations with the
outcome, including time to first expert assessment and 4 ulcer characteristics.
How strong is the model? The model strength is strong (c-statistic = 0.81).
Which variables had the strongest associations? In contrast to the other models
where ulcer factors dominate, patient factors have the strongest associations.
Ulcer
Patient
factors
Health
Higher mortality rates are most-strongly associated with:
• Being 65 or above.
• Hospital admissions for heart failure or renal replacement
therapy.
• Having ischaemia (poor circulation), hindfoot ulceration,
multiple ulcers or a large ulcer.
• Being an ex-smoker.
Lower mortality rates are most-strongly associated with:
• Being obese or having a single ulcer.
Developed
using data on
9,355 ulcers1
Estimated
contribution8,9
Estimated
contribution5
Notes: 1, 8, 9. Please refer to list of footnotes in the Footnote section.

3c. Associations: Modelling
Commentary
48
NDFA team
The most consistent theme in this year’s modelling work has been the
dominance of ulcer factors in predicting outcomes, particularly ischaemia
(poor circulation). The exception is 6 month mortality, where patient factors
such as age and other illnesses such as heart failure are most important.
Patients that wait two or more weeks for expert assessment are less likely to
be alive and ulcer free at 12 weeks. This supports the key NDFA
recommendation that care providers should work together to prevent delays in
expert assessment, through the creation of simple and rapid referral pathways.
Despite the inclusion of nearly 27,000 ulcer episodes, the underlying
weakness of the ‘alive and ulcer-free’ model shows that a large part of
the variation in healing remains unexplained. The NDFA will continue
to investigate whether the power of the models can be improved,
using additional hospital admission, structural and NDA variables.
The centrality of ulcer factors in predicting most outcomes reinforces the key
NDFA message that reducing the proportion of severe ulcers at first expert
assessment should lead to better outcomes. Improving life expectancy may
require a greater focus on secondary cardiovascular risk management.
i

4a. Variation: Risk-adjusted variation
Results and findings
49
National Diabetes Foot Care Audit
Fourth Annual Report

4a. Variation: Risk-adjusted variation
Overview
How is this measured? Statistical models for four NDFA outcomes were built: ‘alive and ulcer free’, ‘foot disease-
related admission’, ‘major amputation’ (above the ankle) and ‘6 month mortality'. The models were used to estimate the
number of patients expected to experience the event at each organisation. The expected figures were then compared
0
50
100
150
200
0
100
200
300
400
500
600
Standardised ratio
Expected number of patients
Organisation
Average
2SD limits
3SD limits
Higher @ 2SD
Lower @ 3SD
with the observed number of patients undergoing the
event, to produce a standardised ratio (SR).
How are results reported? If more patients
had the event than expected the SR is greater than 100
and if there were fewer than expected the SR is less
than 100.
Deviation from 100 does not necessarily mean that an
organisation is performing better or worse than
expected. Instead, control limits (2 and 3 standard
deviations) are used to assess whether the SR for an
organisation is within an expected range or
not. Results are displayed on a funnel plot.
Higher @ 3SD
Expected
50
Audit questions Is there variation between care providers,
once casemix has been accounted for?
Why is this important? Adjusting for each providers’
unique patient casemix allows fairer comparisons between services.
Funnel plot
Key findings
Following casemix adjustment, a small numbers
of providers had worse than expected or better
than expected outcomes for being ‘alive and ulcer
free’ and having ‘foot disease-related admissions’.
i

0
20
40
60
80
100
120
140
160
180
200
0
100
200
300
400
500
600
700
800
900
1000
Standardised healing ratio
Expected number alive and ulcer free at 12 weeks
4a. Variation: Risk-adjusted variation
Alive and ulcer free: by region
Key finding
Three regions have higher and
five lower than expected
numbers of patients that are
‘alive and ulcer free’ at 12 weeks.
Figure 4.1: Risk-adjusted outcomes3: alive and ulcer free2 at 12 weeks, by region4,
England and Wales, 2014-18
51
Notes: 2, 3, 4. Please refer to list of footnotes in the Footnote section.
i
Regions = 44 Sustainability and
Transformation Partnerships
(STPs) in England and 7 Local
Health Boards (LHBs) in Wales.

0
20
40
60
80
100
120
140
160
180
200
0
50
100
150
200
250
300
350
400
450
Standardised healing ratio
Expected number alive and ulcer free at 12 weeks
4a. Variation: Risk-adjusted variation
Alive and ulcer free: by provider
Figure 4.2: Risk-adjusted outcomes3: alive and ulcer free2 at 12 weeks, by provider5,
England and Wales, 2014-18
52
Key finding
Four providers have higher and six lower than expected
numbers of patients that are ‘alive and ulcer free’ at 12 weeks.
Notes: 2, 3, 5. Please refer to list of footnotes in the Footnote section.
i

0
20
40
60
80
100
120
140
160
180
200
0
50
100
150
200
250
300
350
400
450
Standardised admission ratio
Expected number of foot disease admissions within 6 months
4a. Variation: Risk-adjusted variation
Foot disease-related admissions: by region
Key finding Five regions had lower and
three higher than expected numbers of patients
having foot-disease-related admissions.
Figure 4.3: Risk-adjusted outcomes3: foot disease-related admissions within 6 months, by region4,
England and Wales, 2014-17
53
Notes: 3, 4. Please refer to list of footnotes in the Footnote section.
i
Regions = 44 Sustainability and
Transformation Partnerships
(STPs) in England and 7 Local
Health Boards (LHBs) in Wales.

0
50
100
150
200
250
300
0
50
100
150
200
1Standardised admission ratio
Expected number of foot disease admissions within 6 months
4a. Variation: Risk-adjusted variation
Foot disease-related admissions: by provider
Figure 4.4: Risk-adjusted outcomes3: foot disease-related admissions within 6 months, by provider5,
England and Wales, 2014-17
54
Key finding Five providers have lower and
five higher than expected numbers of patients
having foot-disease-related admissions
Notes: 3, 5. Please refer to list of footnotes in the Footnote section.
i

0
20
40
60
80
100
120
140
160
180
200
0
5
10
15
20
25
30
Standardised amputation ratio
Expected number of patients having major amputations within 6 months
4a. Variation: Risk-adjusted variation
Major amputation: by region
Figure 4.5: Risk-adjusted outcomes3: major amputation within 6 months, by region4,
England and Wales, 2014-17
55
Key finding
No regions have a higher
than expected number of
patients having major
amputations (above the
ankle), though two are lower.
Notes: 3, 4. Please refer to list of footnotes in the Footnote section.
i
Regions = 44
Sustainability and
Transformation Partnerships (STPs) in England
and 7 Local Health Boards (LHBs) in Wales.

0
20
40
60
80
100
120
140
160
180
200
0
10
20
30
40
50
60
Standardised mortality ratio
Expected deaths within 6 months
4a. Variation: Risk-adjusted variation
6 month mortality: by region
Key finding
No regions have higher or lower
than expected numbers of patients
that die within six months.
Figure 4.6: Risk-adjusted outcomes3: 6 month mortality9,10, by region4,
England and Wales, 2017-18
56
Notes: 3, 4, 9, 10. Please refer to list of footnotes in the Footnote section.
i
Regions = 44 Sustainability and
Transformation Partnerships
(STPs) in England and 7 Local
Health Boards (LHBs) in Wales.

This publication does not define providers as outliers. This is because:
•
At 10-20 per cent, NDFA case ascertainment is not high enough to
robustly identify outliers.
•
Some of the models, particularly ‘alive and ulcer free’, are not strong
enough to robustly identify outliers.
•
Risk-adjusted outcomes are new to NDFA and providers need an
opportunity to review the initial outcomes and methodology.
•
Because this year’s work was exploratory in nature, the NDFA modelling
cohorts were not split into the test and training cohorts typically used for
outlier identification.
The NDFA may identify outliers in future publications.
4a. Variation: Risk-adjusted variation
Commentary
57
NDFA team
For ulcer healing and foot
disease hospital admissions,
substantial variation was found
even when adjusting for casemix.
Whilst the relative strength of
these models should be factored-
in, providers with worse than
expected outcomes at three
standard deviations (3SD) should
nonetheless consider whether
changes to local care structures
or processes could improve their
outcomes.
It is reassuring that there are no
regions with unusually high major
amputation (above the ankle) or
mortality rates.
i
Interpreting local results
Risk-adjusted results for providers
and STPs are available in the NDFA
interactive local reports. Providers
should undertake a review of local
practice if they are 3SD or more
above or below the expected value.
3SD above
3SD below
Expected

4b. Variation: Time to first expert assessment
Results and findings
58
National Diabetes Foot Care Audit
Fourth Annual Report

4b. Variation: Time to first expert assessment
Overview
59
Audit question: Does the time until a patient is
first assessed by the specialist foot care service vary
across England and Wales?
How is this measured?
The percentage of ulcers in a provider which have
been seen in less than two weeks is calculated for
each provider that had at least 50 relevant ulcer
cases recorded during the audit period.
Why is this important? The audit has continued
to show that shorter times to first assessment are
associated with less severe ulcers (SINBAD 0-2) and
improved outcomes for patients. Variation in
assessment times between providers may be related
to differences in outcomes amongst patients from
different regions, as suggested by the ‘alive and ulcer
free2’ and ‘foot disease-related admission’ models
(see Slide 49).
Key findings
Across England and Wales there is
substantial variation in the proportions of
ulcer episodes where the interval between
first healthcare assessment and arrival at
the specialist team is less than two weeks:
•
Amongst networks there is an 35
percentage point difference.
•
Amongst providers there is an 87
percentage point difference.
0
20
40
60
80
100
0
Min
Max
Networks
Providers
Notes: 2. Please refer to list of footnotes in the Footnote section.

44.9
50.6
52.4
55.1
56.0
58.1
62.0
62.9
65.7
66.8
70.6
74.5
80.4
0
10
20
30
40
50
60
70
80
90
Wessex
Cheshire
and
Merseyside
East of
England
Thames
Valley
South West
London
South East
Coast
East
Midlands
Yorkshire
and the
Humber
Wales
West
Midlands
Greater
Manchester
…
Northern
England
Per cent
Network
National
4b. Variation: Time to first expert assessment
By network
60
Figure 4.7: Ulcers having expert assessment within 14 days6, by network,
England and Wales, 2015-18 (rounded1)
Notes: 1, 6. Please refer to list of footnotes in the Footnote section.

4b. Variation: Time to first expert assessment
By provider
61
0
10
20
30
40
50
60
70
80
90
100
Total (n=96;
median=61.3)
Percentage of ulcers seen within 14 days
Out of range⁷
* Range = Between 1.5 x IQR below the lower quartile
and 1.5 x IQR above the upper quartile.
Figure 4.8: Ulcers having expert assessment within 14 days6, by provider8,
England and Wales, 2015-18 (rounded1)
There is an 85 percentage point difference
in the proportion of cases where the
interval between first healthcare
assessment and arrival at the specialist
team is less than two weeks
Notes: 1, 6, 7, 8. Please refer to list of footnotes in the Footnote section.
i

4b. Variation: Time to first expert assessment
Commentary
62
NDFA team
The NDFA has shown that being seen in less than 2 weeks is associated with a
marked reduction in ulcer severity (see Slide 40), which itself is associated with
better patient outcomes (see Slide 24). It is therefore concerning that there is
such wide variation between providers, with the proportion seen in less than 2
weeks ranging from 45 to 80 per cent at network level.
Every effort should therefore be made to increase the proportions seen in less
than 2 weeks across all organisations, thereby improving equality of access and
optimising patient outcomes.
Recommendation
Commissioners should work with services to ensure that referral
pathways conforming to NICE guidance for people with diabetic
foot ulcers are in place.

Appendix: Modelling
Methodology
63
National Diabetes Foot Care Audit
Fourth Annual Report

Appendix: Modelling
Inclusion criteria
Which patients are included?
NDFA ulcer episodes had to meet the following
criteria to be included (all models unless stated):
1.
Be the patient's first recorded ulcer in NDFA.
2.
Be linked to the NDA core dataset.
3.
Have both age and sex recorded.
4.
Have had first expert assessment within
specified parameters:
•
A&UF: 14 July 2014 (start of audit) to 31
March 2018 (end of NDFA cohort).
•
FDA and Maj Amp: 14 July 2014 to 31
December 2017 (to allow full 6 months
follow-up using admissions data).
•
Mortality: 1 April 2017 (earliest permitted by
information governance) to 4 February 2018
(to allow full 6 months post-trace follow-up).
5.
Have ulcer status recorded at 12 weeks
(A&UF).
6.
Have mortality data traced by the Office for
National Statistics (Mortality).
64
Abbreviations
Alive and ulcer free = A&UF
Major amputation = Maj Amp
Foot disease-related admission = FDA
6 month mortality = Mortality
Variable selection A longlist of 27 categorical predictor
variables was identified for potential inclusion. To ensure that the
final model was as robust as possible, the suitability of each variable
was reviewed with respect to the following criteria, with identified
data issues classified as of low, medium or high severity:
•
Data quality: what proportion of the data is missing?
•
Strength: how strongly is the predictor variable associated with
the outcome? Are the associations due to missing data?
•
Stability: is the predictor variable consistently found to have a
significant association with the outcome (e.g. when modelled
separately, in groups of similar variables or when the cohort is
partitioned).
•
Other: for example, are there other variables which may have a
collinear relationship to the chosen variable (e.g. between ‘Age
band’ and ‘Diabetes duration’).
i

Appendix: Modelling
Selection process
Table A.1: Variable selection grid3
for logistic regression models,
England and Wales, 2014-18
65
Key findings
•
Half of the chosen
variables were ulcer
characteristics.
•
Time to first expert
assessment was retained
for ‘alive and ulcer free’
and ‘foot disease-related
admissions’ only.
Variable type
Variable name
Variable retained?
3
Alive and
ulcer free
2
Foot disease-
related admission
Major
amputation
Death
Patient demographics
at first expert
assessment
Age band
✖
✔
✔
✔
BMI
✖
✖
✖
✔
Deprivation quintile
✖
✖
✖
✖
Diabetes duration
✔
✔
✖
✖
Diabetes type
✖
✖
✖
✖
Ethnicity
✖
✖
✖
✖
Sex
✔
✔
✖
✖
Smoking status
✔
✖
✔
✔
Patient health in year
preceding first expert
assessment
HbA1c < 58 mmol/mol
✖
✖
✖
✖
Blood pressure < 140/80
✖
✖
✖
✖
Cholesterol < 5mmol/L
✖
✖
✖
✖
Angina
✖
✖
✖
✖
Myocardial infarction
✔
✖
✖
✖
Heart failure
✔
✔
✖
✔
Stroke
✖
✖
✖
✖
Renal replacement therapy
✔
✔
✔
✔
Diabetic ketoacidosis
✖
✖
✖
✖
Care processes prior to
first expert assessment
Foot risk surveillance
✖
✖
✖
✖
Time to first expert assessment
✔
✔
✖
✖
Ulcer characteristics at
first expert assessment
Ulcer number (single or multiple)
✔
✔
✖
✔
Charcot status
✔
✖
✔
✖
Site (on hindfoot)
✔
✖
✔
✔
Ischaemia (poor circulation)
✔
✔
✔
✔
Neuropathy (loss of feeling)
✔
✔
✖
✖
Bacterial infection
✔
✔
✔
✖
Area (large ulcer ≥ 1cm2)
✔
✔
✔
✔
Depth (to tendon or bone)
✔
✔
✔
✖
Notes: 2, 3. Please refer to list of footnotes in
the Footnote section.
i

Key findings
•
‘6 month mortality’ and
‘major amputation’ (above
the ankle) were the
strongest models.
•
‘Alive and ulcer free’ was
the weakest model,
meaning that much of the
variation is not explained by
the variables included in the
model.
Appendix: Modelling
Model strength
How strong are the models?
The predictive power or goodness of fit of a model can be assessed by the c-statistic (See Glossary:
Statistical terms), which ranges from 0.5 (no better than chance) to 1.0 (perfect fit). The c-statistics of
the models are shown on Figure A.1 below.
66
Figure A.1: Predictive strength of logistic regression models4,
England and Wales, 2014-18
Notes: 4. Please refer to list of footnotes in the Footnote section.
‘FD admission’ = foot disease-related admission; ‘Major amp’ = major amputation (above the
ankle); ‘Mortality’ = 6 month mortality.
i

Appendix: Modelling
Alive and ulcer free: Variable strength
67
Ischaemia
(poor
circulation)
Area
(large ulcer
≥1cm2)
Depth (to
tendon or
bone)
Time to
first
expert
assess-
ment
Ulcer
number
(single or
multiple)
Bacterial
infection
Diabetes duration
Charcot
Heart failure
Sex
Smoking status
Myocardial infarction
Renal replacement
therapy
Site (on
hindfoot)
Neuropathy
(loss of feeling)
Notes: 5. Please refer to list of footnotes in the Footnote section.
i
Key:
Blue shades = patient / health variables
Grey shades = ulcer variables
Yellow shades = care processes
Area of circle proportionate to relative
contribution of variable5.
Area of circle
proportionate
to relative
contribution of
variable5

Appendix: Modelling
Alive and ulcer free: Category strength
Less likely
Ulcer factors
▲Self-referred
▼Time2assm’t 14d-2mths
▼Infection ▼Neuropathy ▼On
hindfoot ▼Inactive Charcot
Patient factors
▼Male ▼Diabetes 10-19yrs ▼Current
smoker ▼RRT ▼Diabetes 20+yrs
▼Heart failure ▼Myocardial infarction
More likely
LIMITATIONS
The predictive power
of the model is just
below reasonable
(c-statistic = 0.69)
Healed?
✓
68
▲Single ulcer
▲Female
▼Multiple ulcers ▼Time2assm’t
>2mnths ▼Deep ulcer
▼Large ulcer ▼Ischaemia
✖
Notes: Italics = confidence
interval close to line of no
effect (1.0). Underlined = very
strong effect. Please see
Glossary for explanation of
terms.
i

Figure A.2: Odds ratios of factors associated with being alive and ulcer free2 at 12 weeks, England and Wales, 2014-18
More likely
Equally likely
Less likely
●
■
69
Appendix: Modelling
Alive and ulcer free: Forest plot
a. Female vs Male
b. Diabetes duration 10-19 years vs 0-9 years
c. Diabetes duration 20+ years vs 0-9 years
d. Smoking status: Current smoker vs Never smoked
e. Smoking status: Ex-smoker vs Never smoked
f. Heart failure: Yes vs No
g. Myocardial infarction: Yes vs No
h. RRT: Yes vs No
i. Time to first expert assessment: Self-referred vs 3-13 days
j. …0-2 days vs 3-13 days
k. …14 days to 2 months vs 3-13 days
l. …>2 months vs 3-13 days
m. Ulcer number: Multiple vs Single
n. Charcot: Yes vs No
o. Charcot: Possible vs No
p. Charcot: Inactive vs No
q. Charcot: Unknown vs No
r. Site (on hindfoot): Yes vs No
s. Ischaemia: Yes vs No
t. Neuropathy: Yes vs No
u. Bacterial infection: Yes vs No
v. Area (large ulcer ≥1cm²): Yes vs No
w. Depth (to tendon or bone): Yes vs No
Line of no effect
i
Notes: 2. Please refer to list of footnotes
in the Footnote section.

Appendix: Modelling
Foot disease admission: Variable strength
70
Ischaemia
(poor
circulation)
Depth (to
tendon or
bone)
Bacterial
infection
Area
(large ulcer
≥1cm2)
Diabetes duration
Sex
Renal replacement
therapy
Age
band
Heart
failure
Ulcer number
(single or
multiple)
Neuropathy
(loss of feeling)
Time to first
expert
assessment
Notes: 5. Please refer to list of footnotes in the Footnote section.
i
Key:
Blue shades = patient / health variables
Grey shades = ulcer variables
Yellow shades = care processes
Area of circle proportionate to relative
contribution of variable5.
Area of circle
proportionate
to relative
contribution of
variable5

Appendix: Modelling
Foot disease admission: Category strength
Yes
Less likely
▲Heart failure
▲RRT
▲Diabetic = 20+yrs ▲Male
▲Diabetic = 10-19yrs
Ulcer factors
▲Single ulcer
▲Multiple ulcers
▲Neuropathy
▲Time2assm’t = 0-2 days
▼All care procs = No
▼No foot exam
▼First ulcer
▼Time2assm’t = 3-13 days
▼Single ulcer
▼On hindfoot ▼Neuropathy
▼Deep ulcer ▼Charcot ▼Ass't >2
mnths ▼Large ulcer ▼Ischaemia
Patient factors
▼Age = 80+
▼Current smoker
▼Female
▼Age 65-79
▲Deep ulcer
▲Ischaemia
▲Infection ▲Large ulcer
More likely
No
LIMITATIONS
The predictive power
of the statistical model
is reasonable
(c-statistic = 0.74)
Admission?
71
Notes: Italics = confidence
interval close to line of no
effect (1.0). Underlined = very
strong effect. Please see
Glossary for explanation of
terms.
i

Figure A.3: Odds ratios of factors associated with foot disease admissions within 6 months, England and Wales, 2014-17
Less likely
Equally likely
More likely
●
■
72
Appendix: Modelling
Foot disease admission: Forest plot
Line of no effect
a. Age band: 0-39 vs 40-64
b. Age band: 65-79 vs 40-64
c. Age band: 80+ vs 40-64
d. Sex: Female vs Male
e. Diabetes duration 10-19 years vs 0-9 years
f. Diabetes duration 20+ years vs 0-9 years
g. Heart failure: Yes vs No
h. RRT: Yes vs No
i. Time to first expert assessment: Self-referred vs 3-13 days
j. …0-2 days vs 3-13 days
k. …14 days to 2 months vs 3-13 days
l. …>2 months vs 3-13 days
m. Ulcer number: Multiple vs Single
n. Ischaemia: Yes vs No
o. Neuropathy: Yes vs No
p. Bacterial infection: Yes vs No
q. Area (large ulcer ≥1cm²): Yes vs No
r. Depth (to tendon or bone): Yes vs No
i

Appendix: Modelling
Major amputation: Variable strength
73Ischaemia
(poor
circulation)
Area
(large
ulcer ≥1cm2)
Site (on
hindfoot)
Age
band
Notes: 5. Please refer to list of footnotes in the Footnote section.
i
Key:
Blue shades = patient / health variables
Grey shades = ulcer variables
Yellow shades = care processes
Area of circle proportionate to relative
contribution of variable5.
Area of circle
proportionate
to relative
contribution
of variable5
Smoking
status
Renal
replace-
ment
therapy
Charcot
Bacterial
infection
Depth (to
tendon or bone)

Appendix: Modelling
Major amputation: Category strength
Yes
Less likely
▲Current smoker
▲RRT
▲Ex-smoker
Ulcer factors
▲Single ulcer
▲Deep ulcer
▲Infection
▼All care procs = No
▼No foot exam
▼First ulcer
▼On hindfoot ▼Neuropathy
▼Deep ulcer ▼Charcot ▼Ass't >2
mnths ▼Large ulcer ▼Ischaemia
Patient factors
▼Age = 80+
▼Current smoker
▲Large ulcer
▲On hindfoot
▲Ischaemia
▲Charcot
More likely
No
STRENGTH:
The predictive power
of the statistical model
is just below strong
(c-statistic = 0.79)
Major amputation?
74
Notes: Italics = confidence
interval close to line of no
effect (1.0). Underlined = very
strong effect. Please see
Glossary for explanation of
terms.
i

Figure A.4: Odds ratios of factors associated with major amputation within 6 months, England and Wales, 2014-17
Less likely
Equally likely
More likely
●
■
75
Appendix: Modelling
Major amputation: Forest plot
Line of no effect
a. Age band: 0-39 vs 40-64
b. Age band: 65-79 vs 40-64
c. Age band: 80+ vs 40-64
d. Smoking status: Current smoker vs Never smoked
e. Smoking status: Ex-smoker vs Never smoked
f. RRT: Yes vs No
g. Charcot: Yes vs No
h. Charcot: Possible vs No
i. Charcot: Inactive vs No
j. Charcot: Unknown vs No
k. Site (on hindfoot): Yes vs No
l. Ischaemia: Yes vs No
m. Bacterial infection: Yes vs No
n. Area (large ulcer ≥1cm²): Yes vs No
o. Depth (to tendon or bone): Yes vs No
i

Appendix: Modelling
6 month6,7 mortality: Variable strength
76
Age
band
Heart
failure
Ischaemia
(poor
circulation)
Site (on
hindfoot)
Renal
replacement
therapy
Area
(large
ulcer
≥1cm2)
Ulcer
number
(single or
multiple)
Smoking
status
BMI
Notes: 5, 6, 7. Please refer to list of footnotes in the Footnote section.
i
Key:
Blue shades = patient / health variables
Grey shades = ulcer variables
Yellow shades = care processes
Area of circle proportionate to relative
contribution of variable5.
Area of circle
proportionate
to relative
contribution of
variable5

Appendix: Modelling
6 month mortality: Category strength
Yes
Less likely
▲RRT
▲Current smoker
▲Ex-smoker
Ulcer factors
▲Single ulcer
▲Large ulcer
▼All care procs = No
▼No foot exam
▼First ulcer
▼On hindfoot ▼Neuropathy
▼Deep ulcer ▼Charcot ▼Ass't >2
mnths ▼Large ulcer ▼Ischaemia
▼Single ulcer
Patient factors
▲Age = 80+
▲Heart failure
▲Age = 65-79
▼Current smoker
▼Obese
▲Ischaemia ▲On hindfoot
▲Multiple ulcers
More likely
No
STRENGTH
The predictive power
of the statistical model
is strong
(c-statistic = 0.81)
Death?
77
Notes: Italics = confidence
interval close to line of no
effect (1.0). Underlined = very
strong effect. Please see
Glossary for explanation of
terms.
i

Figure A.5: Odds ratios of factors associated with 6 month mortality, England and Wales, 2017-18
Less likely
Equally likely
More likely
●
■
78
Appendix: Modelling
6 month mortality: Forest plot
Line of no effect
a. Age band: 0-39 vs 40-64
b. Age band: 65-79 vs 40-64
c. Age band: 80+ vs 40-64
d. BMI: Underweight vs Healthy
e. BMI: Overweight vs Healthy
f. BMI: Obese vs Healthy
g. Smoking status: Current smoker vs Never smoked
h. Smoking status: Ex-smoker vs Never smoked
i. Heart failure: Yes vs No
j. Renal replacement therapy: Yes vs No
k. Ulcer number: Multiple vs Single
l. Site (on hindfoot): Yes vs No
m. Ischaemia: Yes vs No
n. Area (large ulcer ≥1cm²): Yes vs No
i

Appendix: Modelling
Estimated contribution
79
Model
c-
statistic
Pairs
Guesses
Reduction in
incorrect guesses
when included
Correct
Incorrect
000s
000s
000s
000s
%
All variables
0.700
1,000
700
300
Variable excluded
Age band
0.550
1,000
550
450
150
33.3%
Ethnicity
0.680
1,000
680
320
20
6.3%
Sex
0.699
1,000
699
301
1
0.3%
Model comparison example: A simple model contains
three variables: age band, ethnicity and sex. The dataset has 1,000,000 possible pairs where one record
has the outcome (1) and the other does not (0). When run, the model assigns a higher probability to (1)
than for (0) for 700,000 pairs (correct guesses), giving a concordance (or c-statistic) of 0.700. Real
models are also likely to have ties, which are counted as half a correct guess.
To perform a model comparison, the logistic regression is re-run with one (and only one) of the predictor
variables removed each time. The resultant c-statistics indicate how much the removed variable contributed
to the final model. Example results are shown in the table above right.
Age band
Sex
Ethnicity
Which variables contribute most to a logistic
regression model? The complexity of interactions
between variables in a model makes it difficult to untangle their
relative contributions. Nonetheless an estimate of a variable’s
contribution can be made using the model comparison
technique, as shown in the example below.
When age band is removed, the number of incorrect guesses increases from 300,000 to 450,000, a difference of 150,000. Therefore
the inclusion of age band reduces the proportion of incorrect guesses by 33.3 per cent (150,000 / 450,000): this is the estimated
contribution. Using the same methodology, ethnicity and sex have estimated contributions of 6.3 and 0.3 per cent respectively. It
can therefore be deduced that age band makes the largest contribution to the model’s predictive power. To aid visualisation, variables
can be represented as a shape whose area is based on the relative size of their estimated contribution (see above right).
Notes: 1. Estimated contributions cannot be added together. 2. Results for variables in weaker models tend to be smaller
because the overall c-statistic limits the maximum size of the estimated contribution.
i

Footnotes
Details
80
National Diabetes Foot Care Audit
Fourth Annual Report

Footnotes: Results (1)
81
Footnotes for: 2. Results
1.
Counts have been rounded. Counts between 1 and 7 are represented as a 5. All counts greater than 7
have been rounded to the nearest five. Percentages are derived from rounded values.
2.
‘Alive and ulcer-free’ includes those patients who have had surgery (including major and minor
amputation), provided all wounds have healed. Please see Glossary: Outcomes for further information.
3.
Recommendations 1.3.3-7 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
4.
Recommendation 1.3.8 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
5.
Recommendations 1.4.1-2 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
6.
The 2018 NDFA Provider Survey added the requirement that the urgent referral pathway is available 7
days a week.
7.
The capacity to record whether a patient was lost to follow up was added to the audit system in August
2016. Patients who have been lost and were recorded in the audit prior to this date may appear as an
‘unknown’ outcome instead of ‘lost to follow up’.
8.
Percentage where the ulcer status at 12 weeks is known.
9.
To ensure a full six months of hospital data was available for assessment at the point of analysis, patients
are included where their first assessment by the specialist foot care service in the NDFA took place prior to
2018.
Continued on following slide.

Footnotes: Results (2)
82
Footnotes for: 2. Results (continued)
10. Foot disease identified at any point during the admission. Please see Glossary: Foot disease-related
admission for further information.
11. Only includes bed days within the 6 months following first expert assessment. Excludes day cases. Please
see Glossary: Length of stay and bed days for further information.
12. The entire hospital stay is included, including time after the 6 month cut-off and prior to the first assessment,
where applicable. Excludes day cases. Please see Glossary: Which admissions are included? for further
information.
13. To comply with information governance requirements, patients were only sent for mortality tracing at the
Office for National Statistics (ONS) if they had an ulcer episode first assessed from 1 April 2017
onwards.
14. Patients recorded with less severe (SINBAD 0-2) and severe (SINBAD 3+) ulcers are counted under each
ulcer severity. Severity breakdown figures may not match overall totals.
15. Patients traced through ONS had their life status (and date of death) confirmed as of the date the trace was
conducted. Not all patients could be successfully traced by this method.
16. Mortality derived from life status at 12 weeks as submitted to the audit, not life status traced from ONS.
17. Mortality derived from life status traced from ONS, not life status life as submitted to the audit.

Footnotes: Associations
83
Footnotes for: 3. Associations
1.
Counts have been rounded. Counts between 1 and 7 are represented as a 5. All counts greater than 7
have been rounded to the nearest five. Percentages are derived from rounded values.
2.
‘Alive and ulcer-free’ includes those patients who have had surgery (including major and minor
amputation), provided all wounds have healed. Please see Glossary: Outcomes for further information.
3.
Recommendations 1.3.3-7 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
4.
Recommendation 1.3.8 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
5.
Recommendations 1.4.1-2 from the NICE guidelines: http://www.nice.org.uk/guidance/ng19.
6.
An urgent referral for expert assessment is available if necessary.
7.
Denominator excludes self-referrals.
8.
Estimated contribution derived from the percentage decrease in incorrect guesses when the stated
variable(s) is included the model, compared to when excluded. Please see Appendix: Modelling –
Estimated contribution for further information.
9.
The combined estimated contribution of all factors used in the final model, by variable type.
10. Mortality derived from life status traced from ONS, not life status life as submitted to the audit.
11. ‘Death within six months’ was used for mortality modelling because longer durations (e.g. ‘death within one
year) reduced the number of eligible patients and thereby reduced the statistical power
of the model.

Footnotes: Variation
84
Footnotes for: 4. Variation
1.
Counts have been rounded. Counts between 1 and 7 are represented as a 5. All counts greater than 7
have been rounded to the nearest five. Percentages are derived from rounded values.
2.
‘Alive and ulcer-free’ includes those patients who have had surgery (including major and minor
amputation), provided all wounds have healed. Please see Glossary: Outcomes for further information.
3.
So as not to adjust for clinical practice, care processes such as time to first expert assessment have been
excluded from the model.
4.
44 Sustainability and Transformation Partnerships (STPs) in England and 7 Local Health Boards (LHBs) in
Wales.
5.
119 NHS Trusts and Independent Healthcare Providers (IHPs) in England and 7 Local Health Boards
(LHBs) in Wales.
6.
Excluding ulcers seen after the patient self-referred.
7.
Providers with outcome rates outside the interquartile range (IQR) by more than 1.5 times the IQR are
shown as ‘out of range’.
8.
Only includes providers that submitted 50+ ulcers in the audit year (excluding self-referred).
9.
Mortality derived from life status traced from ONS, not life status life as submitted to the audit.
10. ‘Death within six months’ was used for mortality modelling because longer durations (e.g. ‘death within one
year) reduced the number of eligible patients and thereby reduced the statistical
power of the model.

Footnotes: Appendix
85
Footnotes for: Appendix
1.
Counts have been rounded. Counts between 1 and 7 are represented as a 5. All counts greater than
7 have been rounded to the nearest five. Percentages are derived from rounded values.
2.
‘Alive and ulcer-free’ includes those patients who have had surgery (including major and minor
amputation), provided all wounds have healed. Please see Glossary: Outcomes for further
information.
3.
The process for selecting predictor variables is summarised in Appendix: Modelling - Inclusion
criteria.
4.
Categories derived from Hosmer and Lemeshow (2000).
5.
Estimated contribution derived from the percentage decrease in incorrect guesses when the stated
variable(s) is included the model, compared to when excluded. Please see Appendix: Modelling –
Estimated contribution for further information.
6.
Mortality derived from life status traced from ONS, not life status life as submitted to the audit.
7.
‘Death within six months’ was used for mortality modelling because longer durations (e.g. ‘death
within one year) reduced the number of eligible patients and thereby reduced the statistical
power of the model.

Glossary
Information and definitions
86

Glossary: Data sources
87
Data collected in the NDFA for each ulcer episode:
•
Patient characteristics (NHS number, date of birth)
•
Time interval to first expert assessment from first presentation to a healthcare professional
•
Ulcer characteristics (SINBAD elements, Charcot foot disease, Single / multiple ulcer status)
•
Clinical outcomes (Patient status at 12 weeks after assessment: Alive / Dead / Lost to follow
up, Ulcer free / Persistent ulceration).
Data linked from core National Diabetes Audit (NDA):
•
Patient characteristics (Diabetes duration, smoking status, sex, ethnicity, etc.)
•
Treatment targets (HbA1c, cholesterol, blood pressure)
Data linked from Hospital Episode Statistics (HES) and Patient Episode
Database for Wales (PEDW):
•
Data related to foot disease admissions and length of stay after the first expert assessment.
•
Data related to major amputations and length of stay after the first expert assessment.
•
Data related to diabetes related complications (DKA, RRT, cardiovascular incidents etc.)
preceding first expert assessment.
Data linked from Office for National Statistics (ONS)
Life status: Date of death

Glossary: Healthcare providers
NDFA data is submitted by specialist foot care services that treat people with diabetic foot ulcers. This
includes community and hospital based organisations.
Service providers are the specialist foot care service’s parent organisation. This is typically an NHS
Trust in England or a Local Health Board (LHB) in Wales. It may also be an independent healthcare
provider (IHP).
Commissioners decide what health services are needed and ensure that they are provided. Clinical
Commissioning Groups (CCG) in England and LHBs in Wales are responsible for commissioning
healthcare services.
88
The National Institute for Health and
Care Excellence (NICE) produces
guidelines for the treatment of
diabetic foot problems. All diabetes
foot care services should follow
these guidelines, so that people with
diabetes receive the best possible
foot care.

Glossary: Patient pathway
The first expert assessment of the foot ulcer is undertaken by the specialist foot care service. Patients may self-refer
to the specialist foot care service (self-referral) or they may be referred following presentation to a health
professional (e.g. GP community team, Accident and Emergency or another specialist foot care service).
At 12 and 24 weeks following the first expert assessment, the specialist foot care service will record whether the patient
is alive and ulcer-free (i.e. all ulcers present at the start of this episode have fully healed and no other ulcers remain
unhealed). Being ulcer-free also includes those patients who have had surgery (including major and minor amputation),
provided all wounds have healed. Persistent ulcers are ulcers that have not healed.
Healed at 12 weeks includes all ulcer episodes reported as healed at 12 weeks. Healed at 24 weeks includes all ulcer
episodes reported as healed at 24 weeks plus those reported as healed at 12 weeks, unless a new ulcer episode
occurred within 12 weeks of their 12 week assessment.
89

Glossary: Referrals to the foot care service
90
People seen by the specialist foot care service are generally referred to the foot care team by a
health professional.
This will often be by a general practitioner (GP) who has identified a foot ulcer. Less often it will be
by a hospital consultant – where a patient is referred after attending an A&E department, or after
they have been seen by a specialist in another department (such as orthopaedics, renal services or
dermatology). People may also be referred by community nurses, or another part of the specialist
diabetes service.
Some people are seen by the specialist service after they have ‘self-referred’.
These people have usually had an earlier foot ulcer and know the foot care team,
or may have been identified as high-risk and attend a foot protection service.
They will have been encouraged to contact the specialist foot care service at the
first sign of trouble.
Most people with diabetes that develop a new foot ulcer do not and cannot refer themselves directly to a
specialist foot care service and must be referred by a health professional – usually their GP.

Glossary: 2018 NDFA Provider Survey
The 2018 NDFA Provider Survey asked NHS Trusts in England and Local Health Boards in Wales the following questions:
91
1. Is there a training programme designed to ensure that all responsible health care professionals have the necessary
competence to undertake foot risk examinations as part of routine annual diabetes review? Yes / No / Don’t know
2. Is there an established pathway for referral of all people with diabetes who are defined as being at increased risk
during annual foot examination to a designated Foot Protection Service (FPS)? Yes / No / Don’t know
3. For a person with new, deteriorating or recurrent diabetic foot disease is there an established pathway which can allow
referral to an expert assessment within 24 hours, 7 days a week, if needed? Yes / No / Don’t know
3b. Are some or all of the following personnel available to undertake the expert assessment – even though they may not
necessarily be available at the same time: Yes / No / Don’t know
●Podiatrist(s)?
●Diabetologist(s)?
●Orthotist(s)?
●Microbiologist(s)?
●Vascular surgeon(s)
●Designated administrative support?
●Appropriate facilities available?
4. Is there a protocol of care for foot ulcers which includes the option for step-down or shared care between the Specialist
Foot Care Services (MDFT) and the FPS? Yes / No / Don’t know
5. Is it possible to get an urgent vascular assessment within 24 hours, seven days a week, if necessary? Yes / No / Don’t
know
6. Is there dedicated time to discuss the management of your patients with vascular services? Yes / No / Don’t know
7. How many patients with diabetic foot ulcers do you estimate your service(s) deal with every year?

Glossary: Ulcer characteristics
Ulcer characteristics are measured at the first expert assessment by the specialist foot care
service. Overall ulcer severity is recorded using the SINBAD scoring system, which scores an
ulcer between 0 (least severe) and 6 (most severe) depending on how many of the 6 SINBAD
elements are present. The 6 SINBAD elements are:

Site (on hindfoot) – Ulcer penetrates the hindfoot (rear of the foot).

Ischaemia – Impaired circulation in the foot.

Neuropathy – Loss of protective sensation in the foot.

Bacterial infection – Signs of bacterial infection of the foot
(e.g. redness, swelling, heat, discharge).

Area (large ulcer ≥ 1cm2) – Ulcer covers a large surface area
(1cm2 or more).

Depth (to tendon or bone) – Ulcer penetrates to tendon or bone.
An ulcer with a SINBAD score of 3 or above is classed as a severe ulcer.
An ulcer with a SINBAD score of less than 3 is classed as a less severe ulcer.
Charcot foot disease is a type of serious bone deformity associated with neuropathy.
92

What are the outcomes for patients?
Alive and ulcer free: A patient is considered to be ‘alive and ulcer free’ if they have no instances of
foot ulceration 12 weeks after their first expert assessment. They may have had a major or minor
amputation, but all wounds must have healed for the patient to be considered alive and ulcer free.
Major amputation: Lower limb amputation is the surgical excision of bone and soft tissue of the
foot or leg. Major amputation (above the ankle) is carried out when all other treatments have failed.
Foot disease-related admission: A hospital admission predominantly associated with inpatient
management of diabetes related foot disease including one or more foot disease related clinical
diagnosis or procedure.
Mortality: A patient that has died a short time after developing a diabetic foot ulcer, from causes
that may or may not be directly related to their foot disease.
Glossary: Outcomes
93
How are outcomes measured?
Alive and ulcer free: The foot service is asked to record the patient’s status approximately 12 weeks after their first
expert assessment, noting whether they are alive or dead, and whether their foot ulceration is still active.
Major amputation/Foot disease-related admission: Hospital episode data from England and Wales is checked to find
any instances of major amputation / foot disease related admission taking place within six months of the patient’s first
expert assessment.
Mortality: Patients are traced using ONS data and the time interval between any dates of death and their first expert
assessment are measured. A patient is only included in mortality measures if sufficient time – 6 months –
has elapsed since their assessment and the date of the mortality trace.

Glossary: Statistical terms (1)
Quartiles: Lists of values can be ranked numerically from lowest to highest.
•
The median is the middle value in the ranked list.
•
The lower quartile is the middle value of the lower half of the ranked list.
•
The upper quartile is the middle value of the upper half of the ranked list.
•
The interquartile range represents values between the lower and upper quartiles – the middle
50 per cent of the values in the ranked list.
94
•
The interquartile range, along with
minimum and maximum range values,
can be plotted on a box and whisker
plot – see example right.
•
Values outside 1.5xIQR below the
lower quartile and 1.5xIQR above the
upper quartile are shown as points
outside the plot.
Box and whisker plot
•
The mean is the average of the values in the list. The mean may be higher or lower than the
median, depending on the extent to which the data is skewed (e.g. by very large values).

Glossary: Statistical terms (2)
Where a result is flagged as significant at 0.05 level, there is only a 5 per cent probability that the
result is due to chance.
Logistic regression is used to examine the relationship between an outcome (e.g. alive and healed at 12 weeks) and
related variables (e.g. ulcer characteristics). Backwards elimination is used to remove variables found not to be
significant at 0.05 level, producing a final model that includes variables with significant associations only
Two outputs are particularly useful when interpreting the results of a logistic regression model:
o
The c-statistic can be used to assess the goodness of fit, with values ranging from 0.5 to 1.0. A value of 0.5
indicates that the model is no better than chance at making a prediction of membership in a group and a value of
1.0 indicates that the model perfectly identifies those within a group and those not. Models are typically considered
reasonable when the c-statistic is higher than 0.7 and strong when the c-statistic exceeds 0.8 (Hosmer and
Lemeshow, 2000).
o
Odds ratios (OR) illustrate how strongly a particular value of a variable is associated with the outcome. The
further from one the ratio is (either above or below), the stronger the association between it and the outcome. For
example, an odds ratio of 0.764 would suggest a stronger association than an odds ratio of 0.830. An odds ratio of
one would show that the variable value has no bearing on how likely the outcome is.
There is always a degree of uncertainty in the calculated odds ratio. This is described by the confidence interval.
The wider the confidence interval, the less certainty there is in the odds ratio. If the confidence intervals are either
side of 1 this indicates that the value taken by the variable has no bearing on how likely the outcome is. Where the
confidence interval approaches 1 this indicates that the association with the outcome may be weak.
95

Glossary: Modelling infographic
Yes
Less likely
Effect size
Details
▲Very large effect OR ≥4.00
▲Large effect OR 2.50 – 3.99
More likely
No
Model strength is
derived from the c-
statistic and adapted
from Hosmer and
Lemeshow (2000).
Outcome
96
●The infographic shows
categories (e.g. age 80+) from
variables (e.g. age) used in the
final model where a significant
association with the outcome
(e.g. death) has been found (p
= 0.05).
●The position of the category
on the infographic is defined by
its odds ratio (OR), using
effect sizes adapted from
Rosenthal (1996). The OR
ranges are shown on the right.
●Categories in italics have
confidence intervals close to
the line of no effect (0.95 -
1.05).
●See Glossary for further
description of Statistical terms.
Patient factors
include:
●Patient
demographics at
first expert
assessment.
●Patient health
in year preceding
first expert
assessment.
Ulcer factors
include:
●Ulcer
characteristics at
first expert
assessment
terms.
●Care
processes prior
to first expert
assessment.
▲Medium effect
OR 1.50 - 2.49
▲Small effect
OR 1.00 - 1.49
OR 0.25 - 0.39 ▼Large effect
OR <0.25 ▼Very large effect
OR xx-xxxx-xxxx
▼Medium effect
▼Current smoker
OR 0.67 - 1.00
▼Small effect
Colours:
Blue = less
desirable.
Orange = more
desirable.

Glossary: Which admissions are included?
97
X
X
X
X
X
X
X
-1
0
1
2
3
4
5
6
7
8
X
X
X
X
Months
First expert
assessment
6 months post-
assessment
Story
A. Admission and event X
occurs within 6 month window
B. Admission overlaps with 6
month window, event X occurs
within 6 month window
C. Admission overlaps with 6
month window, event X occurs
outside 6 month window
D. Admission and event X
outside 6 month window
All admissions includes all hospital stays within or overlapping with the 6 month period after first assessment by the specialist foot care team
(Stories A, B, and C below). Subsets include:
•
Foot disease admissions, where foot disease is identified at any point during the hospital admission, including outside the 6 month window (Stories
A, B, and C below, where event X is the start of the episode of care where foot disease is identified). This ensures that all admissions where foot
disease is a significant factor are included.
•
Revascularisation and amputation admissions, where the related procedures occur within the 6 month window (Stories A and B below, where
event X is the relevant procedure date). Using this criteria ensures that the currency used for
analysis (procedures undertaken within 6 months) is simple and easy to understand.
6 month window
Admission included?
All
admissions
Where event X is…
Foot
disease
Revascul-
arisation
Amput-
ation
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No

Glossary: Length of stay and bed days
98
-1
0
1
2
3
4
5
6
7
8
A
B
C
D
Months
First expert
assessment
6 months post-
assessment
Key
Length of
stay
counted?
Bed days
counted?
Yes
Yes
Yes
No
No
No
Story
Admission
included?
Admitted and
discharged within 6
month window
Yes
Admission overlaps with
assessment, concluded
within 6 months
Yes
Admission overlaps with
end of 6 month window
Yes
Admitted and
discharged outside 6
month window
No
The full duration of the hospital admission contributes towards the length of stay, including days outside the 6 month
window. This ensures that hospital stays that overlap with the beginning or end of the 6 month window are not artificially
shortened. Length of stay is reported using the median (middle) value, which prevents skewing of results by very long stays.
Bed days are only counted if they occur within 6 months of first assessment by the specialist foot care service. This ensures
that the currency (bed days within 6 months of first expert assessment) is easy to understand and also prevents patients with
very long stays (e.g. long-term mental health admissions) from inflating the total.
6 month window

Glossary: Foot disease-related admissions
Diabetic foot disease is defined as a foot affected by ulceration that is associated with neuropathy
and/or peripheral arterial disease of the lower limb in a patient with diabetes1.
People with diabetic foot ulcers sometimes require admission to hospital to treat their foot disease. This occurs when
the condition of the foot threatens survival of either the foot or the patient. Such deterioration is often a result of
infection (requiring intravenous antibiotics, with or without local surgery) or poor arterial blood flow. Resultant hospital
stays and rehabilitation may be lengthy. In extreme cases amputation is required.
To identify foot disease-related admissions, all episodes of hospital care have been
searched for the following clinical procedures or diagnoses predominantly associated
with inpatient management of diabetes related foot disease2:
99
Foot disease clinical diagnoses
• Diabetes mellitus with peripheral
circulatory complications
• Ulcer of the lower limb
• Decubitus ulcer
• Cellulitis
• Osteomyelitis
• Gangrene
• Atherosclerosis
Foot disease clinical procedures
• Debridement of a foot/leg wound
• Minor and major amputation of lower limb
Notes: 1. Alexiadou, K and Doupis, J (2012).
2. Public Health England (2017). Patients may have other conditions which are contributing factors towards their hospital stay.
For reporting purposes, the foot disease may
be identified at any point during the hospital
admission. Single patients may have more
than one admission and/or foot disease type.

Glossary: Amputation procedures
Amputation, or surgical removal, of part of the foot or leg may be required when a diabetic
foot ulcer cannot otherwise be successfully treated. When this is the case then an operation
is needed to surgically excise bone and soft tissue in order to allow healing.
This may be a minor amputation (below the ankle) in which toes or part of the foot are
removed in an attempt to save the leg. When this is not possible, major amputation
(above the ankle) may be required.
Amputation is a life-changing event, with significant physical and
psychological effects. Long hospital stays and periods of rehabilitation
can result.
100
For reporting purposes, amputation must occur within 6 months
of first expert assessment by the specialist foot care service.
Any one patient may have more than one amputation-related
admission and/or amputation procedure.

Further information
Audit references
101

Further information: Summary
•
For more information on the National Diabetes Foot
Care Audit or access to the Service Level Analysis,
please visit the NDFA webpage at
https://digital.nhs.uk/footcare.
•
For further information about this report, please
contact NHS Digital’s Contact Centre on xx-xxxx-xxxx
5678 or email xxx@xxx.xx.
102

Further information: Future plans
103
Over the next 12 months, the NDFA team will:
•
Work with submitters to encourage participation.
Improve case ascertainment by surveying service
providers for estimated number of cases seen.
•
Promote the mini-project done on success factors to
improve outcomes at 12 weeks – alive and ulcer free.
•
Promote the key messages to all service providers
and relevant professional and patient groups.
•
Undertake the Quality Improvement Collaborative.
Key topics chosen include improving the time to first
expert assessment.

Further information: References
•
Abbott CA, Carrington AL, Ashe H, et al. (2002) The North-West Diabetes Foot Care Study: incidence of, and risk
factors for, new diabetic foot ulceration in a community-based cohort. Diabetes Med 2002; 19: 377–84. DOI:
10.1046/j.1464-5491.2002.00698.x
•
Alexiadou, K and Doupis, J (2012) Management of Diabetic Foot Ulcers:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3508111
•
Hosmer DW, Lemeshow S (2000) Applied Logistic Regression (2nd Edition) New York, NY: John Wiley & Sons.
•
Ince P, Abbas ZG, Lutale JK, et al. (2008) Use of the SINBAD classification system and score in comparing
outcome of foot ulcer management on three continents. Diabetes Care 2008; 31: 964-7.
http://care.diabetesjournals.org/content/31/5/964.long
•
Kerr M (2017) Diabetic foot care in England: An economic study: https://www.evidence.nhs.uk/document?id=1915227
•
NICE-recommended care processes http://pathways.nice.org.uk/pathways/foot-care-for-people-with-diabetes
•
NICE Guidelines: Diabetic foot problems: prevention and management; January 2016;
http://www.nice.org.uk/guidance/ng19
•
NHS Digital (2018) National Diabetes Foot Care Audit - 2014-2017 https://digital.nhs.uk/data-and-
information/publications/statistical/national-diabetes-footcare-audit/national-diabetes-foot-care-audit-2014-2017
•
Public Health England (2018): Diabetes footcare profiles https://fingertips.phe.org.uk/profile/diabetes-ft
•
Rosenthal JA (1996) Qualitative Descriptors of Strength of Association and Effect Size,
Journal of Social Service Research, 21:4, 37-59, DOI: 10.1300/J079v21n04_02
104

Further information: Acknowledgements
The NDFA team would like to thank all the teams who have worked hard to
contribute to this unique and valuable insight into the care and outcomes of
people with diabetic foot ulcers.
Development and delivery of the NDFA is guided by a multi-professional advisory group of clinicians and patient
representatives, chaired by Professor William Jeffcoate. The NDFA Advisory Group members include:
105
William Jeffcoate
Consultant Diabetologist, Nottingham University
Hospitals NHS Trust (Chair)
Bob Young
NDA Specialist Clinical Lead
Emma Barron
Head of Health Intelligence (Diabetes), NCVIN, Public
Health England
Alex Berry
Engagement Lead, Diabetes UK
Jonathan Boyle
Consultant Vascular Surgeon, Addenbrooke's
Hospital, Cambridge/Chair National Vascular Registry
Sue Brown
Patient representative
Sheila Burston
Patient representative
Scott Cawley
National Diabetic Foot Co-ordinator for Wales
Mike Churchill
Patient representative
Sophie Colling
NDA Project Support Officer, Diabetes UK
Catherine Gooday
FDUK & Principal Diabetes Podiatrist, Norfolk &
Norwich University Hospital
Michelle Goodeve
Diabetes Lead Podiatrist, Broomfield Hospital,
Chelmsford
Alexandra Harrington
Head of Community Podiatry at Great Western
Hospitals
Naomi Holman
Methodology Advisor, University of Glasgow
Roy Johnson
Patient representative
Jane Lewis
Specialist Podiatrist & Research Lead, Cardiff
Metropolitan University
Claire Meace
Higher Information Analyst, NHS Digital
Julie Michalowski
Audit Manager, NHS Digital
Angela Pinnock
Audit Coordinator, NHS Digital
Gerry Rayman
Consultant Diabetologist, Ipswich Hospital NHS Trust
Michael Sykes
Quality Improvement Lead, Diabetes UK
Andrew Whitehead
Audit Coordinator, NHS Digital
Dean Williams
Professor of Surgery, Betsi Cadwaladr University
Health Board
Corinne Wykes
Patient representative
Arthur Yelland
Senior Information Analyst, NHS Digital

106
The Healthcare Quality Improvement Partnership (HQIP). The National Diabetes Foot Care Audit is part of
the National Clinical Audit and Patient Outcomes Programme (NCAPOP) which is commissioned by the
Healthcare Quality Improvement Partnership (HQIP) and funded by NHS England. HQIP is led by a
consortium of the Academy of Medical Royal Colleges, the Royal College of Nursing and National Voices. Its
aim is to promote quality improvement, and in particular to increase the impact that clinical audit has on
healthcare quality in England and Wales. HQIP holds the contract to manage and develop the NCAPOP
Programme, comprising more than 30 clinical audits that cover care provided to people with a wide range of
medical, surgical and mental health conditions. The programme is funded by NHS England, the Welsh
Government and, with some individual audits, also funded by the Health Department of the Scottish
Government, DHSSPS Northern Ireland and the Channel Islands.
NHS Digital is the trading name of the Health and Social Care Information Centre. It is the trusted source of
authoritative data and information relating to health and care. NHS Digital managed the publication of the
NDFA Fourth Annual Report.
Diabetes UK is the largest organisation in the UK working for people with diabetes, funding research,
campaigning and helping people live with the condition.
The national cardiovascular intelligence network (NCVIN) is a partnership of leading national cardiovascular
organisations which analyses information and data and turns it into meaningful timely health intelligence for
commissioners, policy makers, clinicians and health professionals to improve services and outcomes.
Supported by:
Prepared in collaboration with:

www.digital.nhs.uk
xx-xxxx-xxxx
xxx@xxx.xx
@nhsdigital

This publication may be requested in large print or other formats.
Published by NHS Digital, part of the Government Statistical Service
For further information
digital.nhs.uk
xx-xxxx-xxxx
xxx@xxx.xx
Copyright © 2019, the Healthcare Quality Improvement Partnership, National Diabetes Audit.
All rights reserved.
This work remains the sole and exclusive property of the Healthcare Quality Improvement
Partnership and may only be reproduced where there is explicit reference to the ownership of the
Healthcare Quality Improvement Partnership.
This work may be re-used by NHS and government organisations without permission.