WHAT THIS PAPER ADDS This international Delphi process has generated a core set of items to be captured by vascular quality registries that are specific for acute limb ischaemia (ALI) and supplement previous recommendations for chronic peripheral arterial occlusive disease. This core set can be used to standardise data collection for comparability across registries and thereby facilitate amalgamation of real world data, and comparisons between centres, regions, and countries. Ultimately, harmonised registries will provide a base for international collaboration to fill evidence gaps and contribute to improving the care of patients with ALI. Objective: To develop a minimum core data set for evaluation of acute limb ischaemia (ALI) revascularisation treatment and outcomes that would enable collaboration among international registries. Methods: A modified Delphi approach was used to achieve consensus among international multidisciplinary vascular specialists and registry members of the International Consortium of Vascular Registries (ICVR). Variables identified in the literature or suggested by the expert panel, and variables, including definitions, currently used in 15 countries in the ICVR, were assessed to define both a minimum core and an optimum data set to register ALI treatment. Clinical relevance and practicability were both assessed, and consensus was defined as ! 80% agreement among participants. Results: Of 40 invited experts, 37 completed a preliminary survey and 31 completed the two subsequent Delphi rounds via internet exchange and face to face discussions. In total, 117 different items were generated from the various registry data forms, an extensive review of the literature, and additional suggestions from the experts, for potential inclusion in the data set. Ultimately, 35 items were recommended for inclusion in the minimum core data set, including 23 core items important for all registries, and an additional 12 more specific items for registries capable of capturing more detail. These 35 items supplement previous data elements recommended for registering chronic peripheral arterial occlusive disease treatment. Conclusion: A modified Delphi study allowed 37 international vascular registry experts to achieve a consensus recommendation for a minimum core and an optimum data set for registries covering patients who undergo ALI revascularisation. Continued global harmonisation of registry infrastructure and definition of items allows international comparisons and global quality improvement. Furthermore, it can help to define and monitor standards of care and enable international research collaboration.
