Development and validation of a clinical prediction rule for development of diabetic foot ulceration: an analysis of data from five cohort studies. Issue 1 (25th May 2021)

• Record Type: Journal Article
• Authors: Chappell, Francesca M; Crawford, Fay; Horne, Margaret; Leese, Graham P; Martin, Angela; Weller, David; Boulton, Andrew J M; Abbott, Caroline; Monteiro-Soares, Matilde; Veves, Aristidis; Riley, Richard D
• Is Part Of: BMJ open diabetes research and care. Volume 9:Issue 1(2021)
• Publication Date: 2021-05-25
• Subjects: prevention -- foot ulceration -- epidemiology; Diabetes -- Periodicals; 616.462005
• DOI: 10.1136/bmjdrc-2021-002150
• Languages: English
• ISSNs: 2052-4897

Abstract

Abstract : 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.