Measurement properties of the Haem-A-QoL in haemophilia clinical trials

Abstract

Introduction: Patients with haemophilia on long-acting prophylactic treatment may experience an improvement in health-related quality of life (HRQoL) through reductions in breakthrough bleeds and associated complications, including long-term joint damage, compared with episodic treatment.

Aim: This analysis examined clinical trial data to understand the psychometric characteristics (reliability, validity and sensitivity to change over time) of the Haem-A-QoL Questionnaire in adult males with haemophilia.

Methods: Two recent, multinational, Phase 3 clinical trials of new, long-acting factor concentrates (A-LONG: rFVIIIFc; B-LONG: rFIXFc) assessed HRQoL in adolescent and adult males with severe haemophilia A or B respectively. The adults' baseline assessments, via the 46-item Haem-A-QoL Questionnaire, and change over time at the 6-month assessment were used in the psychometric analyses.

Results: Internal consistency reliability was adequate (Cronbach's alpha > 0.70) for nine of the 10 Haem-A-QoL domains and for 'Total Score' in both trials at baseline (A-LONG, n = 133; B-LONG, n = 73). At baseline, several Haem-A-QoL domains and 'Total Score' demonstrated known-groups and convergent validity when compared with other trial measures, including the EQ-5D (items and total scores) and joint impairment. Change score correlations (baseline to 28 weeks) between the EQ-5D and the Haem-A-QoL 'Total Score', and 'Physical Health' and 'Feelings' domains were moderate in magnitude (│r│ ≥ 0.33; P < 0.03), demonstrating sensitivity to change for these outcome measures in A-LONG.

Conclusion: These psychometric analyses provide evidence of the reliability, validity and ability to detect change of the Haem-A-QoL to assess the HRQoL of adult males with severe haemophilia A and B in longitudinal clinical trials.

Keywords: haemophilia; patient-centred outcome; patient-reported outcome; quality of life; reliability; validity.