Disease-specific measures of quality of life (QoL) for children with haemophilia are now available for use in clinical studies [Haemophilia, 10, 2004, 9-16]. One of these measures, the Canadian Haemophilia Outcomes - Kids' Life Assessment Tool (CHO-KLAT), was developed in Canada with emphasis on the perspectives of children [Pediatr Blood Cancer, 47, 2006, 305-11; Haemophilia, 10, 2004, 34-43]. Another, the Haemo-QoL, was developed in Europe, with emphasis on the perspectives of clinicians [Haemophilia, 8, 2002, 47-54; Haemophilia, 10, 2004, 17-25]. While these two measures are unique and independent, researchers from both studies were collaboratively linked throughout development and testing. This study presents the results of a joint assessment of the two measures with respect to their strengths, limitations and unique contributions. The primary questions addressed were: 1 What is the relationship between the CHO-KLAT and the Haemo-QoL in terms of summary scores and item content? 2 What are the methodological strengths, limitations and unique contributions of each measure? We conducted a retrospective analysis of data from field testing of both measures. The analysis included a comparative assessment of the basic validity, reliability and items used in each measure. Overall, the CHO-KLAT and the Haemo-QoL are promising and valuable measures of QoL for children with haemophilia. Our analyses confirmed the basic psychometric properties of both tools, but identified some discrepancies between them. Additional data will allow for greater understanding of these discrepancies and lend clarity to how the tools should be used in clinical studies (separately or merged). The present recommendation is that the measures be run independently, but preferably concurrently in studies of children with haemophilia.
