NDFA Interval Review: July 2014-March 2021

3. Findings

3.1. Associations: Time to FEA and 12-week outcome

Since data collection started in 2014, the National Diabetes Foot Care Audit (NDFA) has consistently found that faster referral to the specialist foot care service is associated with fewer severe ulcers (see Chart 2) and better 12-week outcomes (Chart 3).

3.2. Changes over time: Time to FEA and ulcer severity

Data from 108,450 ulcer episodes from 2014 to 2021 demonstrate that there has been a rise in the proportion of new ulcer episodes assessed by a specialist foot care service within 13 days of first presentation to any healthcare professional (HCP): from 43% to 46% (Chart 4a). The improvement is even more marked when self-referrals (with no interval collected) are excluded from the denominator: from 61% to 69% (Chart 4b).

Over the same period there has been a steady fall in the percentage of new ulcer episodes graded as severe at FEA (from 48% to 43%, Chart 4a, or 52% to 48% where self-referrals are excluded, Chart 4b).

Notes: (1) The proportion having a FEA within 13 days is higher in Chart 4b because the denominator is lower (with self-referrals excluded). The proportion having a severe ulcer at FEA is also higher in Chart 4b because the excluded group (self-referrals) are less likely to have severe ulcers at FEA (see Chart 2).

3.3. Changes over time: Ulcer healing and co-morbidities

In parallel with the reduction in ulcer severity at FEA, there has been a decrease in the percentage of ulcers which are active (unhealed) at 12 weeks: from 49% to 40% (see Chart 5a).

The proportion of unknown outcomes (missing or lost to follow-up) has risen during this period: from 4% to 13% (Chart 5a). Nonetheless, a fall in active ulcers is still evident when unknown outcomes are excluded (Chart 5b): from 50% to 45%.

The increase in 12-week mortality from 2% to 6% (Chart 5b) is likely to reflect greater co-morbidity at presentation (Appendix 5.6).

Although there have been improvements in ulcer healing at a national level (England and Wales combined), the data collected from 2014 to 2021 provides evidence of marked variation between regions in the mean percentage of ulcers healed by 12 weeks (see Appendix 5.7), from 48% to 68% for less severe ulcers and 27% to 41% for severe ulcers (Chart 6 and Appendix 5.7), where the 12-week outcome is known.

There is also evidence of variation in outcome (healing by 12 weeks) when expressed by service providers, with 13 of 129 providers (10%) having a lower rate of healing than expected (Appendix 5.8), compared to <0.2% that would be found due to normal variation. Although data in this report is unadjusted, variation between providers has been found in previous reports where case-mix adjustment has been applied (see NDFA 2019, p.52).

Chart 6: Percentage of people alive and ulcer-free at 12 weeks after FEA, by region: Severe ulcers, excluding unknown outcomes, England and Wales, 2014-21

3.5. Changes over time: Major amputation within 6 months

Despite the overall improvement in ulcer healing outcomes by 12 weeks, there has been no change in the incidence of major amputation (which is an uncommon event) within 6 months of FEA (see Chart 7 and Appendix 5.9), which remains around 0.6% for less severe ulcers and around 2.7% for severe ulcers.

There is little regional variation in the incidence of major amputation within 6 months throughout England and Wales, even though the incidence appears lower in London than other regions (1.8% for severe ulcers, Appendix 5.10).

The use of a new NDFA outcome measure for assessing long-term response to intervention: the state of being ‘alive and major amputation-free at 1 year’ is demonstrated in Charts 8a and 8b and Appendix 5.11. Charts 8a and 8b show that 90% presenting with less severe ulcers were alive and major amputation-free at 1 year, compared with 82% of those with severe ulcers. Whilst encouraging, it is still notable that almost 1 in 5 people (18%) who present with a severe ulcer are either dead (15%) or have undergone major amputation within 1 year (3%).

3.6. Care structures survey

The NDFA also measures the provision of foot care services using the National Diabetes Audit (NDA) Integrated Specialist Services Structures Survey (ISSSS, abbreviated to ISS), a questionnaire based on National Institute for Health and Care Excellence (NICE) and Getting It Right First Time (GIRFT)-recommended structures and systems for delivery of care to people with diabetes (1) (2). The survey was distributed to healthcare providers in England and Wales in October 2021.

The foot care section of the questionnaire comprised 11 questions on aspects of care delivery which were selected by clinical members of the NDFA Advisory Group. The questions and survey results are shown on the following slide.

Survey results

96 providers responded to the questionnaire: 92 NHS trusts, 3 local health boards (LHBs) and 1 independent healthcare provider (IHP). For comparison, there are 223 NHS trusts and LHBs in England and Wales, although some (e.g. mental health or ambulance trusts) would not be expected to contribute to the ISS. Of those that responded:

• Overall service provision was high, with an average of 8.8 out of 11 services provided.
• From a total of 11 questions, 4 questions received affirmative answers from over 90% of providers. 3 questions received 80-89% and 3 received 70-79% (see Table 1).
• However, only 33% reported that foot care services were integrated with renal services. People with renal disease in diabetes have a high incidence of foot disease (3).

Table 1: Results of the 2021 ISS, England and Wales, October 2021