Inclusion Criteria:  Any patient aged 18 years old or over with chronic limb threatening ischaemia or diabetic foot disease for whom major lower limb amputation is considered or discussed Vascular surgeons / anaesthetists / specialist physiotherapists involved in, or supporting major lower limb amputation decision making  Exclusion Criteria:  Patients under 18 years old Patients undergoing major lower limb amputation for other causes (e.g. trauma or cancer) Any patient/healthcare professional unable or unwilling to provide informed consent. Some patients undergoing emergency major lower limb amputation will have insufficient time to give informed consent Potential participants with an insufficient understanding of English or Welsh to be able to provide informed consent Potential participants unable to complete an interview in English