Adequacy of Clinical Surveillance of Diabetic Patients Requiring Minor Foot Amputations

Foot pathology is the commonest indication for hospital admission in patients suffering with diabetes mellitus (DM).  Malta, a European Union (EU) member state has one of the highest prevalence rates of DM.¹ The number of major limb amputations in Malta has decreased dramatically from a peak of 31/100,000/year in 2003 to 5.6/100,000/year in 2019. The number of minor foot amputations on the other hand remains significantly higher than in most other EU member states at between 76 - 86/100,000/year with an average of 414 minor amputations/year.²

There is no national diabetes register in Malta but the IDF Diabetes Atlas gives an estimate of 40,500.³ A recent cross-sectional study highlighting the prevalence of type 2 diabetes mellitus in the Maltese Islands estimated a prevalence of ~44,400 which amounts to 10.31% of the population.¹ There is no national protocol or guideline for the follow-up of patients with DM. Primary health care is provided by local health centres which are nationally funded, and the private care service which is usually based on single general practitioners, podiatrists and other health care workers working separately and independently. There is no national foot screening programme and diabetes foot care is shared between public and private services.

Monitoring and surveillance of disease progression in patients with DM is guided by international recommendations such as the National Institute for Health and Care Excellence (NICE), the American Diabetes Association (ADA) and the International Diabetes Federation (IDF) which recommend:

• Hba1c testing every 3 months⁴ and then every 6 months if levels are stable.⁵
• Patients should be followed-up regularly by a consultant endocrinologist if the desired treatment goals are not reached. Patients with stable diabetes should still be followed up but longer intervals may be set.⁶
• Podiatry follow-up is also encouraged and patients are usually stratified by risk. This includes (1) low risk with annual foot assessment, (2) moderate risk every 3-6 months, (3) high risk with no immediate concern every 1-2 months and (4) high risk with immediate concern every 1-2 weeks.⁷
• Patients with Type 2 diabetes mellitus (T2DM) should be referred to diabetes educators at the time of diagnosis and the program should be available at the primary care level.⁴
• On diagnosis, GPs should immediately refer adults with T2DM to the local eye screening service. Annual appointments with an ophthalmologist familiar with the management of diabetic retinopathy should be organised. Patients who require more urgent assessment should be seen more regularly.^{6, 8}

The aim of this study was to establish the level of compliance with international recommendations on monitoring and surveillance of patients with DM requiring minor foot amputations (amputations below the level of the ankle including amputation of digits at the phalangeal or metatarsal level), to assess the level of care of diabetes in the public health service and highlight any deficiencies in follow-up.

Materials and Method

Patients with diabetes related foot complications requiring a minor amputation between January 2018 and April 2019 were selected for this project. These were identified from a hospital database obtained from the Clinical Performance Unit which focused mainly around the ‘Diabetic Foot Ward’ at the main teaching hospital. Data was collected retrospectively using the local health care software system iSOFT, which allows accurate blood trending, records hospital admittance and monitors patient follow-up together with attendance. This was used to collect the following information:

• Demographics: gender, age
• Approximate date of diagnosis by noting first reported diabetes related follow-up and/or first known abnormal glucose levels. This confirmed that all patients were already known cases of diabetes.
• Blood investigation trending starting between 2014 to the date of admission Hba1c, glucose, lipid profiles and eGFRs levels and frequency of blood testing
• Patient visit history between 2014 to the date of admission including podiatry, diabetes education, ophthalmic, endocrine outpatients, community diabetes follow-up and follow-up post-amputation.
• Scheduling of follow-up up to 1 year after amputation with diabetes, vascular, podiatry, diabetes education and ophthalmic services.

Electronic case summaries were used to obtain information on hospital admittance/discharge, date and type of amputation. IBM SPSS Statistics (Version 26) was used for data analysis.  Clearance was obtained from data protection office.

Mean totals and percentages were calculated to determine how many patients attended follow-up between 2014-2017. Chi-squared test was used to compare frequency of blood testing along the years. The Kruskall-Wallis test was used to compare Hba1c levels with attendance to follow-up

Results

One hundred and one patients who were known cases of diabetes and underwent a minor amputation between January 2018 and April 2019 were included. Patient age ranged between 41 and 90 years. Male patients amounted to 65 (64.4%) while 36 (35.6%) were female.

A total of 119 amputations were performed, with some procedures involving amputation of more than one toe (Table 1). Left foot amputations were noted to be more frequent than right foot amputations (53.5 vs 46.5%). The 1^st, 2^nd and 5^th toes were the most frequently amputated while the 3^rd and 4^th toe were the least likely to require amputation. A significant proportion of patients had a 2^nd toe amputation at the level of the proximal phalanx while patients with a 5^th toe amputation were more likely to have surgery performed through the metatarsal.

Hba1c, renal profile and lipid profile testing levels since 2014 (table 2) indicate that a very significant proportion of patients never had HbA1c levels, lipid or renal profile checked. The proportion of patients without blood testing has decreased over the years. Hba1c levels in those patients who were tested were significantly above recommended levels in the vast majority of patients (Table 3). LDL levels in the majority of patients were above the acceptable range i.e. 1.8 mmol/L (Table 4). eGFR status of patients was classified according to the 2012 Kidney Disease: Improving Global Outcomes (KDIGO) guideline for chronic kidney disease evaluation ^[9] (Table 5).

Only 35 (34.7%) patients were seen at least once a year in the hospital or community. Hospital attendance (24 (23.8%)) was noted to be greater than community attendance (10 (9.7%)) overall. Those who were attending hospital only and community only had approximately 1-2 visits each year. Only 2 patients (2.0%), were seen in both community and hospital (table 6).

Between 2014-2017, prior to their amputation 66 (65.3%) patients were not booked for any diabetes care appointments either in the hospital or community, 12 (11.9%) failed to turn up and 2 (1.9%) had their appointment cancelled (table 6).

There was no significant difference noted (p=0.463) when comparing Hba1cs in those followed up in hospital, community, both and those patients who were not being seen. (Table 7)

The majority of patients (62 (61.4%)) were not booked for podiatry visits in the 4 years preceding their amputation. Patients who were seen at least once a year (mean total of 39 (38.6%)) had ~2 visits/year between 2014-2017. Eighty-five patients (84.2%) had not been seen by the diabetes education team between 2014-2017. From those who attended, 15 (14.9%), had ~1-2 visits/year in the years preceding the amputation. A total of 48 patients (47.5%) had been seen at ophthalmology department at least once per year and 52 (51.5%) were not being followed-up by ophthalmology services (table 8).

Finally, patient follow-up scheduling up to 1 year post-operatively was also assessed as seen in table 9.

Discussion

This retrospective audit shows that local monitoring and surveillance of patients with diabetes who required minor amputation does not meet international recommendations.

A very significant proportion (34.4%) of patients undergoing minor amputations did not have Hba1c levels tested at all. On a positive note, improvement has been noted in HbA1c, renal and lipid profile testing between 2014 and 2017 (table 3).  The majority of subjects having a minor amputation had uncontrolled T2DM with a mean total of Hba1c of 78.7mmol/mol i.e. 9.36%. This is usually associated with an increased risk of complications related to diabetes⁴ (table 4). A mean eGFR of 57 shows that most patients are well below the normal level and this a strong predictor of macrovascular complications^5,10 (table 6). LDL levels were also noted to be well above the recommended level of 1.8mmol/l as set by the European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS) guidelines for the management of diabetes¹¹(mean total= 2.52) (table 5).

Since the selected cohort includes patients who have already developed complications it is not unexpected that their level of control falls short of international recommendations.  This retrospective analysis revealed that lack of control is mainly attributed to poor patient compliance and a failure of the system to book patients for appointments in the public health service offered. In addition, the very high rate of minor amputations in Malta suggests that poor compliance with international recommendations is more widespread.

In Malta there is no established guideline for diabetes referral, however an unofficial system exists where patients with well controlled diabetes are usually followed-up in the community by a GP while patients with uncontrolled T2DM are seen in hospital by an endocrinologist. From our cohort, a mean 4-year total of only 34.7% were seen in the hospital and/or community with hospital attendance (23.8%) being most predominant. A significant proportion of patients (65.3%) were not seen at all in the 4 years preceding the minor amputation. In most cases patients were simply not followed-up in a given year (51.5%) and only a handful failed-to-attend (11.9%) or had their appointment cancelled (1.9%). Patients followed-up in hospital are more likely to be the more complex cases and more likely to have higher Hba1c levels. The results however do not support this assumption and Hba1c levels in the community (76.1mmol/mol) are only marginally higher than those seen in hospital (74.9mmol/mol) (table 7).

 International guidelines recommend regular follow-up by podiatry, diabetes education teams and ophthalmology. This retrospective analysis showed that a very significant proportion of patients were not seen by podiatry (61.4%), diabetes education (84.2%) or ophthalmology (51.5%) in the 4 years preceding their amputation (table 8).  In the year after their intervention most patients had better follow-up with their endocrinologist/GP, podiatry, diabetes education and ophthalmic. This shows that the measures put in place for follow-up of patients admitted for minor foot amputation are more effective (table 9).

One of the limitations of the study is that the results may not be representative of the general population due to the small cohort size. Also, selected patients are at a higher risk of developing complications and need more intensive follow-up. However, since 2014 an improvement in frequency of blood testing has been noted (table 3) while patient follow-up has remained roughly unchanged (table 7 and 8). Furthermore, since this is a retrospective audit, this analysis does not consider whether patients were being seen in private clinics and data is only limited to the public health service.

Conclusion

This study highlights the poor compliance with international recommendations in those patients with diabetes who underwent a minor foot amputation. The data demonstrates that the very high levels of minor amputations in the country require a concerted effort to ensure that healthcare systems are put in place to improve compliance and quality of care to this vulnerable population.  The fragmentation of health care provision and the lack of a national co-ordinated diabetes care service is likely to be in part responsible for the poor compliance.  Further research is required to determine whether the implementation of more stringent and rigorous follow up in patients with diabetes will lead to a reduction in the number of minor amputations.

Acknowledgements

Our first thanks goes to our supervisor Prof. Kevin Cassar for his continuous support and dedication during this project. We would also like to give our profound thanks to Prof. Liberato Camilleri, Head of the Statistics and Operations Research Department at the Faculty of Science in the University of Malta, for his guidance in the interpretation of the data collected. Finally, we would like to take the opportunity to thank all our friends and family members who were always ready to help along the way.

References

1. Cuschieri S. (2020) The diabetes epidemic in Malta. SEEJPH, posted: 19 February 2020. DOI 10.4119/seejph-3322
2. Grima, M., Said, I., Duncan, J., & Cassar, K. (2018). A review of amputation and revascularisation rates in a small European state. Malta Medical Journal.
3. IDF (2019). IDF Diabetes Atlas 9th Edition. International Diabetes Federation. Retrieved from https://www.diabetesatlas.org/data/en/country/123/mt.html
4. (2017). IDF Clinical Practice Recommendations for managing Type 2 Diabetes in Primary Care. International Diabetes Federation.
5. Duff, C. J., Solis-Trapala, I., Driskell, O. J., Holland, D., Wright, H., Waldron, J. L., . . . Fryer, A. A. (2019). The frequency of testing for glycated haemoglobin, HbA1c, is linked to the probability of achieving target levels in patients with suboptimally controlled diabetes mellitus. Clinical Chemistry and Laboratory Medicine (CCLM), 57(2), 296–304. doi:https://doi.org/10.1515/cclm-2018-0503
6. American Diabetes Association (2003, January). Standards of Medical Care for Patients With Diabetes Mellitus. Diabetes Care, 26(suppl 1), s33-s50. doi:doi.org/10.2337/diacare.26.2007.S33
7. NICE (2015). Diabetic foot problems: prevention and management. National Institute of Health and Care Excellence (UK).
8. NICE (2019). Type 2 diabetes in adults overview. National Institute for Health and Clinical Excellence.
9. (2013) KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Journal of the International Society of Nephrology, 3(1), 19-63.
10. Dabla, P. K. (2010, May 15). Renal function in diabetic nephropathy. World Journal of Diabetes, 48–56. doi:10.4239/wjd.v1.i2.48
11. ESC/EAS. (2019). 2019 ESC/EAS Guidelines for the Management of Dyslipidemias: Lipid Modification to Reduce Cardiovascular Risk: The Task Force for the Management of Dyslipidemias of the European Society of Cardiology (ESC) and European Atherosclerosis Society (EAS). Eur Heart J.

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