A retrospective cohort study on European Reference Network for Rare Vascular Diseases 5 outcome measures for Hereditary Haemorrhagic Telangiectasia in Denmark

Abstract
Background Hereditary Haemorrhagic Telangiectasia (HHT) is an autosomal dominant disorder characterized by several clinical symptoms including epistaxis, arteriovenous malformations (AVM), and telangiectasia. In 2018, European Reference Network for Rare Vascular Diseases (VASCERN) recommended five outcome measures for HHT-patients to guide health care providers, some with limited experience in treating HHT, and thereby maximizing the number of HHT-patients receiving good care. The outcome measures cover the following aspects: 1) 90% of the patients should receive a pulmonary AVM (PAVM) screening; 2) 90% of the patients should receive written advice on nosebleed; 3) 70% should be assessed for iron deficiency; 4) 100% of the patients should receive written advice on antibiotic (AB) prophylaxis prior to dental and surgical procedures, and; 5) 100% of relevant patients should receive written advice on pregnancy. We have introduced the outcome measures as Benchmarks in our HHT-centre and wanted to evaluate the extend of implementation we have achieved. We constantly struggle to secure the best possible treatment of our HHT-patients.Methods The study was a non-interventional retrospective study. All data was collected from medical journals and from the Danish HHT-database. Results A total of 180 HHT-patients were included, all diagnosed in the period from January 1st 2016 to December 31st 2020. All patients were screened for PAVM. We could confirm that 66% of patients who had epistaxis received thoroughly advice. Assessment for iron deficiency was performed in 80 % of the adult patients. Thoroughly advice on antibiotic prophylaxis was documented in 75%. Thoroughly advice on pregnancy was documented in 80% of female patients 15-45 years of age. There were no significant differences over time for any of the outcome measures. Conclusions The Danish HHT-centre reached the target threshold for outcome measures 1 and 3. We could not document reaching the target thresholds for outcome measures 2, 4, and 5. As information and education is a very important part of HHT care, we will focus on and document that all patients receive the relevant advice and as part of our care, we will in the near future implement an electronic solution with advice for HHT patients.