Development and validation of a clinical prediction rule for development of diabetic foot ulceration: an analysis of data from five cohort studies

Francesca M. Chappell (Lead / Corresponding author), Fay Crawford, Margaret Horne, Graham P. Leese, Angela Martin, David Weller, Andrew J. M. Boulton, Caroline Abbott, Matilde Monteiro-Soares, Aristidis Veves, Richard D. Riley

Research output: Contribution to journalArticlepeer-review

8 Citations (Scopus)
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Introduction: The aim of the study was to develop and validate a clinical prediction rule (CPR) for foot ulceration in people with diabetes.

Research design and methods: Development of a CPR using individual participant data from four international cohort studies identified by systematic review, with validation in a fifth study. Development cohorts were from primary and secondary care foot clinics in Europe and the USA (n=8255, adults over 18 years old, with diabetes, ulcer free at recruitment). Using data from monofilament testing, presence/absence of pulses, and participant history of previous ulcer and/or amputation, we developed a simple CPR to predict who will develop a foot ulcer within 2 years of initial assessment and validated it in a fifth study (n=3324). The CPR's performance was assessed with C-statistics, calibration slopes, calibration-in-the-large, and a net benefit analysis.

Results: CPR scores of 0, 1, 2, 3, and 4 had a risk of ulcer within 2 years of 2.4% (95% CI 1.5% to 3.9%), 6.0% (95% CI 3.5% to 9.5%), 14.0% (95% CI 8.5% to 21.3%), 29.2% (95% CI 19.2% to 41.0%), and 51.1% (95% CI 37.9% to 64.1%), respectively. In the validation dataset, calibration-in-the-large was -0.374 (95% CI -0.561 to -0.187) and calibration slope 1.139 (95% CI 0.994 to 1.283). The C-statistic was 0.829 (95% CI 0.790 to 0.868). The net benefit analysis suggested that people with a CPR score of 1 or more (risk of ulceration 6.0% or more) should be referred for treatment.

Conclusion: The clinical prediction rule is simple, using routinely obtained data, and could help prevent foot ulcers by redirecting care to patients with scores of 1 or above. It has been validated in a community setting, and requires further validation in secondary care settings.

Original languageEnglish
Article numbere002150
Number of pages7
JournalBMJ Open Diabetes Research and Care
Issue number1
Early online date25 May 2021
Publication statusPublished - 25 May 2021


  • epidemiology
  • foot ulceration
  • prevention

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism


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