Quality of life in a large multinational haemophilia B cohort (The B-Natural study) – Unmet needs remain

Erik Berntorp, Petra LeBeau, Margaret V. Ragni, Munira Borhany, Yasmina L. Abajas, Michael D. Tarantino, Katharina Holstein, Stacy E. Croteau, Raina Liesner, Cristina Tarango, Manuela Carvalho, Catherine McGuinn, Eva Funding, Christine L. Kempton, Christoph Bidlingmaier, Alice Cohen, Johannes Oldenburg, Susan Kearney, Christine Knoll, Philip KuriakoseSuchitra Acharya, Ulrike M. Reiss, Roshni Kulkarni, Michelle Witkop, Stefan Lethagen, Rebecca Krouse, Amy D. Shapiro, Jan Astermark

Research output: Contribution to journalArticlepeer-review


Introduction: The B-Natural study is a multicentre, multinational, observational study of haemophilia B (HB) designed to increase understanding of clinical manifestations, treatment and quality of life (QoL). Aim: To characterise and compare QoL in HB across disease severity groups and individuals with inhibitors to identify gaps in treatment. Methods: A total of 224 individuals from 107 families were enrolled from a total of 24 centres in North America (n = 16), Europe (n = 7) and Asia (n = 1). Of these, 68 (30.4%) subjects had severe (<1 IU/dL), median age 15.6 years, 114 (50.9%) moderate (1–5 IU/dL), age 13.3 years, and 42 (18.8%) mild (>5–< 40 IU/dL), age 12.1 years, disease. Twenty-nine participants had inhibitors or a history of inhibitors. Three versions of the EQ-5D instrument were used as a measure of QoL: proxy (ages 4–7), youth (ages 8–15) and self (age 16+). Each instrument included a visual analogue scale ranging from 100 (best health) to 0 (worst health) to assess current day's health (EQ VAS). Range-of-motion (ROM) for elbows, knees and ankles was assessed using a four-point scale, from which a composite score was calculated. Results: In all severity groups, a proportion of subjects showed less than optimal QoL. The majority of the mild and moderate severe participants reported a normal EQ-5D health profile (79% and 72%, respectively), whereas about half (47%) of the severe participants and only 13% of the inhibitor participants reported this profile. Conclusion: The B-Natural study reveals impacted QoL in all disease severities of HB including those with inhibitors. Unmet needs remain and include nonsevere HB.

Original languageEnglish
Pages (from-to)453-461
Issue number3
Early online date2022
Publication statusPublished - 2022

Subject classification (UKÄ)

  • Cardiac and Cardiovascular Systems

Free keywords

  • EQ-5D
  • FIX
  • haemophilia B
  • inhibitor
  • prophylaxis
  • QoL


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