The Australia and New Zealand Diabetic and Ischaemic Foot Outcomes Study (ANZDIFOS)

There is limited high-quality data on the factors that contribute to limb loss in patients with diabetes-related foot disease (DFD) in New Zealand and Australia. Furthermore, wound, ischaemia and foot infection (WIfI) staging has not been validated in the Australasian cohort. The aim of this study was to (1) report on the presentation, management and outcomes of DFD (wound healing, major limb amputation [MLA], amputation-free survival [AFS] and mortality at 1-year), and (2) validate the association of WIfI stage on outcomes.

This was an observational prospective study of patients with DFD and a wound at three centres in New Zealand and Australia from 2020 to 2022. Data on presentation, management, amputation and mortality at 1-year was collected. Outcomes were stratified by presenting WIfI stage. Wound healing and survival were assessed with Kaplan-Meier curves, time-to-healing with Fine-Gray competing risks, AFS with logistic regression and survival with Cox proportional hazards.

Two hundred and seventy-six patients (384 limbs) were recruited, with WIfI stage 1 (47.9%), 2 (21.1%), 3 (19.5%) and 4 (12.5%). At 1-year, 71.4% of wounds healed, with WIfI stage associated with healing, p < 0.001. At 1-year 16.6% of limbs had underwent a MLA, with the proportion increasing by WIfI stage. Poorer AFS was observed with increasing WIfI. Mortality at 1-year increased with WIfI stage, p < 0.001.

This study reports on the presentation, management and outcomes from DFD in New Zealand and Australia. WIfI staging appropriately classifies patients with DFD and correlates with healing, MLA, AFS and survival at 1-year.