MJA
MJA InSight
MJA Careers
Research

Diabetes-related lower-limb amputations in Australia

Craig B Payne
Med J Aust 2000; 173 (7): 352-354.
Research

Diabetes-related lower-limb amputations in Australia

Craig B Payne

MJA 2000; 173: 352-354
For editorial comment, see Colman & Beischer;
see also Campbell et al.

Abstract - Methods - Results - Discussion - Acknowledgements - References - Authors' details
- - More articles on Endocrinology


Abstract Objective: To identify the prevalence of diabetes-related lower-limb amputations and its regional variations in Australia.

Design and setting: Cross-sectional analysis of a hospital morbidity dataset in Australia.

Methods: Analysis of the National Hospital Morbidity Database of all hospital separations for the ICD codes 84.10-84.19 (lower-limb amputations) and 250.0-250.9 (diabetes and its complications) for the financial years 1995-96 to 1997-98.

Main outcome measure: Number of lower-limb amputations in people with diabetes mellitus in Australia, and in each State and Territory.

Results: 7887 diabetes-related lower-limb amputations were reported during the study period, with a mean ± SD of 2629 ± 47 per year. The prevalence in Australia was 13.97 per 100 000 total population, and varied from 11.34 per 100 000 in the Australian Capital Territory to 20.68 per 100 000 in South Australia.

Conclusion: Diabetes-related lower-limb amputation poses a substantial personal and public health cost in Australia.


The loss of a limb is a frequent complication of diabetes mellitus, most commonly the result of diabetic foot problems such as ulcers and infection. The risk of amputation of the lower limb is increased up to 15-fold in people with diabetes. Contributory factors include the loss of sensation from the sensory neuropathy; deformity and gait abnormalities from the motor neuropathy; abnormal blood flow regulation from the autonomic neuropathy; ischaemia from the macrovascular disease; limited joint mobility from the increased glycolation of collagen; poor glycaemic control; and increased risk of infection. It is usually some trigger or traumatic event superimposed on these risk factors that causes a lesion such as ulceration or infection which starts a pathway leading to amputation.2,3 Inadequate and inappropriate self-care is also a major factor.

The National Diabetic Foot Disease Management Program, as part of the National Diabetes Strategy and Implementation Plan,4 has called for a 50% reduction in lower-limb amputations by the year 2005. Data on diabetes-related lower-limb amputations in Australia are lacking.4 The aim of my study was to identify the prevalence of diabetes-related lower-limb amputations in Australia, as well as variations among States and Territories.


Methods Approval for the study was given by the Faculty of Health Sciences Human Ethics Committee at La Trobe University (Victoria).

The dataset for my analysis was obtained from the Australian Institute of Health and Welfare (AIHW) for the financial years 1995-96, 1996-97 and 1997-98. The AIHW obtained permission from the relevant State and Territory agencies to release the information, which did not include any personal identifying data. Information was obtained from the National Hospital Morbidity Database (compiled by the AIHW) on all separations from public and private hospitals in Australia for the International Classification of Disease (ICD)5 procedure codes 84.10 to 84.19 (amputations of the lower extremity) and diagnosis codes 250.0 to 250.9 (indicating diabetes and its complications) as the principal or secondary diagnoses. Information was also obtained on sex, age, ethnicity, duration of hospital stay, and State or Territory of residence of each patient who had an amputation. A spreadsheet was used to determine the number of amputations in each region and the duration of hospital stay. The data for each State and Territory were age- and sex-standardised6 to the estimated Australian population as at 30 June 1998.7 This information was then used to determine the rate for each State and Territory.


Results A total of 7887 diabetes-related lower-limb amputations (68.2% in men) were recorded as occurring in the three-year period, with an annual mean of 2629 ± 47 (SD) (Box 1). Most occurred in the 65-79 years age groups (Box 2). The age- and sex-standardised prevalence of lower-limb amputation varied among the States and Territories (Box 3), from 11.34 per 100 000 total population in the Australian Capital Territory to 20.68 per 100 000 total population in South Australia. The duration of hospital stay (Box 3) also varied among the States and Territories. The shortest mean hospital stay was 20.0 (95% CI, 17.4-22.6) days in South Australia and the longest was 40.2 (95% CI, 23.1-57.3) in the Northern Territory. It was not possible to analyse the ethnicity data, as two States/Territories would not agree to the release of this information.


Discussion The 2629 diabetes-related lower-limb amputations in Australia per year represent a significant personal burden on people with diabetes and on the healthcare system. The loss of a limb is a personal tragedy for those with diabetes,8 and is associated with a deterioration of functional status and residential status,9 with a significant number requiring long term care.10 People with diabetes who have a lower-limb amputation have a higher mortality rate,1,11 especially perioperative mortality.12 Half the people with an amputation will require an amputation of the remaining limb within five years.13,14 This morbidity results in high medical and rehabilitation costs: about 10% of diabetes-related healthcare costs are associated with lower-limb amputations.15

The sex differences in lower-limb amputation rates of about 2:1 for men to women reported here are consistent with previous reports,20 and may be related to the levels of adherence to advice, the amount of social support, psychological factors such as denial, or a higher prevalence of the physiological risk factors for amputation such as macrovascular disease.21 Ethnicity is a well-recognised risk factor for lower-limb amputation,22,23 but was not analysed in this project as two of the States/Territories would not release this information.

The duration of hospital stay has been identified as one of the main determinants of cost associated with a lower-limb amputation.17 The mean number of bed-days reported here (24.7 days) is less than the mean in the Netherlands15 (42 days) and more than that in the United States16 (15.9 days). There was a large variation among the Australian States and Territories in the mean hospital stay; South Australia has the highest prevalence of lower-limb amputation, but the shortest mean stay. Regional variations have been reported previously in New Zealand for hospital admissions for diabetic foot complications.18 Such regional variations are most likely to be due to variations in clinical practice and access to services.19

A number of shortcomings are inherent in the type of dataset analysed here. Of primary concern is the accuracy of the recording of data. Diabetes has been reported as being under-recorded on discharge records,24,25 so the numbers reported here are most likely an underestimate. There is also concern that the dataset does not distinguish the number of multiple amputations in the same individual; this will bias the population towards the characteristics of these individuals.

A number of modifiable risk factors for diabetes-related lower-limb amputation have been identified,26-28 including the lowering of blood pressure, improving glycaemic control and reducing or eliminating smoking. With proper foot care, patient education and provision of appropriate services, such as regular podiatric care, a reduction in the number of amputations can be achieved.4 A number of studies have shown the value of multidisciplinary teams in reducing amputations by up to 50%.29-32 A reduction of this magnitude has the potential to save up to $24 million (based on the assumption that the direct cost of diabetes-related lower-limb amputations in Australia is $48 million per year4). However, a significant proportion of this potential saving will need to be directed to programs to prevent the amputations.



Acknowledgements
Funding for this project was provided by the Australasian Podiatric and Education Foundation.


References

  1. Nelson R, Gohdes DM, Everhart JE, et al. Lower extremity amputations in NIDDM: 12 year follow up study in Pima Indians. Diabetes Care 1998; 11: 8-16.
  2. Payne CB, Scott RS, Moir C. Trigger events for acute admission to hospital for diabetic foot disease. Australas J Podiatric Med 1998; 32: 57-64.
  3. Pecoraro RE, Reiber GE, Burgess EM. Pathways to diabetic amputation -- basis for prevention. Diabetes Care 1990; 13: 513-521.
  4. Colagiuri S, Colagiuri R, Ward J. National Diabetes Strategy and Implementation Plan. Canberra: Diabetes Australia, 1998.
  5. The International classification of diseases. 9th Revision. Clinical modification. Commission on Professional and Hospital Activities. Michigan, 1990.
  6. Beaglehole R, Bonita R, Kjellstrom T. Basic epidemiology. Geneva: World Health Organization, 1993.
  7. Australian Bureau of Statistics. Australian demographic statistics. Canberra: ABS, 1999. (Catalogue no. 3101.0.)
  8. Fitzpatrick MC. The psychologic assessment and psychosocial recovery of the patient with an amputation. Clin Orthop 1999; 381: 98-107.
  9. Frykberg RG, Arora S, Pomposelli FB, LoGerfo F. Functional outcome in elderly following lower extremity amputation. J Foot Ankle Surg 1998; 37: 181-185.
  10. Lavery LA, van Houtum WH, Armstrong DG. Institutionalisation following diabetes related lower extremity amputation. Am J Med 1997; 103: 383-388.
  11. Faris I, Duncan H, Young C. Factors affecting the outcome of diabetic patients with foot ulcers or gangrene. J Cardiovasc Surg 1988; 29: 736-740.
  12. Ebskov LB. Relative mortality in lower limb amputees with diabetes mellitus. Prosthet Orthot Int 1996; 20: 147-152.
  13. Silbert S. Amputation of the lower extremity in diabetes mellitus. Diabetes 1952; 1: 297-299.
  14. Ebskov LB. Diabetic amputation and long-term survival. Int J Rehab Res 1998; 21: 403-408
  15. Van Houtum WH, Lavery LA, Harkless LB. The costs of diabetes-related lower extremity amputations in the Netherlands. Diabetic Med 1995; 12: 777-781.
  16. Ashry HR, Lavery LA, Armstrong DG, et al. Cost of diabetes related amputations in minorities. J Foot Ankle Surg 1998; 37: 186-190.
  17. Solomon C, van Rij A, Barnett R, et al. Amputations in the surgical budget. N Z Med J 1994; 107: 78-80.
  18. Payne CB, Scott RS, Moir C. Hospital discharges for diabetic foot disease in New Zealand 1980-1993. Diabetes Res Clin Pract 1998; 39: 69-74.
  19. Sanders D, Coulter A, McPherson K. Variations in hospital admission rates: a review of the literature. London: King Edward's Hospital Fund, 1989.
  20. Armstrong DG, Lavery LA, van Houtum WH, Harkless LB. The impact of gender on amputation. J Foot Ankle Surg 1997; 36: 66-69.
  21. Vogt MT, Wolfson SK, Kuller LH. Lower extremity arterial disease and the aging process -- a review. J Clin Epidemiol 1992; 45: 529-542.
  22. Lavery LA, Ashry HR, van Houtum W, et al. Variation in the incidence and proportion of diabetes related amputations in minorities. Diabetes Care 1996; 19: 48-51.
  23. Simmons D, Scott D, Kenealy T, Scragg R. Foot care among diabetic patients in South Auckland. N Z Med J 1995; 108: 106-108.
  24. Williams DRR, Fuller JH, Stevens LK. Validity of routinely collected hospital admissions data on diabetes. Diabetic Med 1998; 6: 320-324.
  25. Phillips DE, Mann JI. Diabetes -- inpatient utilisation, costs and data validity. Dunedin 1985-9. N Z Med J 1992; 105: 313-315.
  26. Moss SE, Klein R, Klein BEK. The prevalence and incidence of lower extremity amputation in a diabetic population. Arch Intern Med 1992; 152: 610-616.
  27. Lehto S, Ronnemaa T, Pyorala K, Laakso M. Risk factors predicting lower extremity amputations in patients with NIDDM. Diabetes Care 1996; 19: 607-611.
  28. Hamalainen H, Ronnemaa T, Halonen JP, Toikka T. Factors predicting lower extremity amputations in patients with type 1 or type 2 diabetes mellitus: a population based 7 year follow-up study. J Intern Med 1999; 246: 97-103.
  29. Edmonds ME, Blundell MP, Morris ME, et al. Improved survival of the diabetic foot -- the role of a specialised foot clinic. QJM 1986; 60: 763-771.
  30. Malone LM, Snyder M, Anderson G, et al. Prevention of amputation. Am J Surg 1989; 158: 520-523.
  31. Ebskov LB. Epidemiology of lower extremity amputation in Denmark. Int Orthop 1991; 15: 285-288.
  32. Larson J, Apelqvist J, Agardh CD, Stenstrom A. Decreasing incidence of major amputation in diabetic patients -- a consequence of a multidisciplinary foot care team approach. Diabetic Med 1995; 12: 770-777.

(Received 25 Nov 1999, accepted 20 Jul 2000)


Authors' details
Faculty of Health Sciences, La Trobe University, Melbourne, VIC.
Craig B Payne, DipPod(NZ), MPH, Lecturer, Department of Podiatry.

Reprints: Dr C B Payne, Department of Podiatry, School of Human Biosciences, Faculty of Health Sciences, La Trobe University, Bundoora, VIC 3083.
c.payneATlatrobe.edu.au


Make a comment





1: Number of diabetes-related lower-limb amputations in Australia
Men Women Total

1995-96
1996-97
1997-98
1729
1849
1804
851
824
830
2580
2673
2634
Mean ±SD

1795 ±61

834 ±14 2629 ±47
Total 5382
(68%)
2505
(32%)
7887
Back to text
 
Click in box for larger version
Back to text
 
3: Age- and sex-standardised prevalence and duration of hospital stay for lower-limb amputations in Australia for 1995-1998
Mean ±SD lower extremity
amputations per year
Rate (95% CI) per
100000 total population

New South Wales
Victoria
Queensland
South Australia
Western Australia
Tasmania
Northern Territory
Australian Capital Territory
Australia
801 ±13
695 ±12
468 ±8
308 ±6
219 ±4
67 ±2
36 ±1
35 ±1
2629 ±47
12.59 (9.54-15.78)
14.87 (11.6-18.17)
13.48 (10.56-16.45)
20.68 (17.18-24.18)
11.89 (8.90-14.88)
14.21 (12.63-16.17)
18.86 (15.53-22.19)
11.34 (8.34-13.56)
13.97 (11.98-15.87)
Duration of hospital stay

Mean (95% CI) bed days Median (range) bed days

New South Wales
Victoria
Queensland
South Australia
Western Australia
Tasmania
Northern Territory
Australian Capital Territory
Australia
24 (23-26)
22 (21-23)
30 (28-33)
20 (17-23)
26 (22-29)
27 (19-35)
40 (23-57)
33 (18-47)
25 (24-26)
18 (1-210)
16 (1-183)
21 (1-283)
13.5 (1-176)
18 (1-183)
21 (1-197)
24 (1-224)
24 (1-223)
17 (1-283)
Back to text
Craig B Payne