The association between health utility and joint status among people with severe haemophilia A: findings from the KAPPA register.

INTRODUCTION: People with severe haemophilia A have reportedly impaired health related quality of life (utility) mainly due to recurrent bleeding, arthropathy and treatment burden.

AIM: To estimate utilities and evaluate their potential correlates - most importantly the joint status - among people with severe haemophilia A.

METHODS: In this cross-sectional study, eligible participants had severe haemophilia A, were aged ≥15, negative for factor VIII inhibitor and included in the KAPPA register of Denmark, Norway and Sweden. Data on demographics, treatment history, haemophilia joint health score, and EQ-5D utility were obtained from the register. We used box plots to present utilities and joint status and ordinary least squares regression to evaluate correlates of utilities. Participants were consecutively enrolled in the KAPPA register between April 2013 and June 2016.

RESULTS: Overall, 173 participants with median age of 34 (interquartile range: 25-45) were included. Twelve (6.9%) participants were on episodic treatment while 161 (93.1%) were treated using prophylaxis. Concomitant diseases and positive inhibitor history were reported for 73 (43.2%) and 21 (12.1%) participants, respectively. The highest median utility (1.0) was observed among those aged <29 on prophylaxis and those aged 30-44 who had started prophylaxis by age 3. In the multi-variable regression, joint scores of 16-25 (Coef. -0.18, 95% CI: -0.30, -0.06), 26-35 (Coef. -0.21, 95% CI: -0.36, -0.06) and >35 (Coef. -0.37, 95% CI: -0.52, -0.23) were associated with lower utilities.

CONCLUSION: Moderate to severe joint manifestations are associated with reduced utilities among persons with severe haemophilia A.