INTRODUCTION:
Patients with diabetic foot ulcers (DFU) suffer from diabetes-related complications and comor-bidities. Hyperbaric oxygen therapy (HBOT) is a treatment modality with limited capacity used in the treatment of DFUs. It is important to ensure that HBOT is offered to patients who are suitable for this treatment regarding effect, compliance and life expectancy. The objective of the present study was to describe the population of patients with DFU who were referred to HBOT in Denmark in the 1999-2016 period.

METHODS:
All patients with DFU who were treated at the HBOT chamber in Copenhagen during the study period were considered. Patients with an invalid social security number or an incorrect diagnosis were excluded. Data on comor-bidities, amputation and death were extracted from the Danish National patient Registry and the Danish Civil Registration System. Continuous data were described as median values and binary data were described as proportions. The probability estimate for survival and amputation was investigated by constructing Kaplan-Meier curves.

RESULTS:
The cohort included 148 patients. Patients were mainly referred from the Capital Region (92%) and multi-disciplinary wound care centres were the primary referring departments (67%). Comorbidity rates were high with an initial median Charlson Comorbidity Index score of five. The five-year amputation and mortality estimates after referral were 73.5% and 51.8%, respectively.

CONCLUSIONS:
The study showed that Danish DFU patients who are offered HBOT are in advanced stages of their disease, and the referral hinges on local factors such as geography and the referring source rather than on standardised procedures.