CHO-KLAT Background

The Canadian Haemophilia Outcomes – Kids’ Life Assessment Tool (CHO-KLAT) is a disease specific, child-centric health related quality of life (HRQoL) measure initially developed in 2004 (Young et al, Haemophilia, 2004). At the time, there was a lack of disease specific HRQoL measures, and those generic measures that were used did not usually focus on children’s perspectives.

The initial development work included children with haemophilia and their parents from four comprehensive haemophilia treatment centres across Canada: Halifax, Toronto, Winnipeg, and Vancouver. Through a series of literature reviews, semi-structured discussions with adults and children with haemophilia, and separate focus groups with children with haemophilia and parents of children with haemophilia, 228 candidate items were identified for inclusion in the HRQoL measure.

Items were through a series of steps, including a survey of physician members of the Association of Hemophilia Clinic Directors of Canada (AHCDC), data from the focus groups, and merging similar items. The resulting 77 retained items included 50% of the items generated by the children themselves (compared with 33% of the items generated from all other sources), highlighting the child-centric nature of the tool.

The original version of the CHO-KLAT underwent pilot testing and cognitive debriefing, which resulted in changes to approximately 10% of the questions, as well as dividing two questions into two components each. The revised version contained 79 items (CHO-KLAT79). A validation and reliability study resulted in further item reduction, with 35 strongly performing items retained from the original 79, referred to as CHO-KLAT35. The CHO-KLAT35 was shown to be a reliable and valid measure of HRQoL among boys with haemophilia (Young et al., Pediatric Blood & Cancer, 2006).

In 2008, we began a detailed process of linguistic translation and cognitive debriefing to develop versions of the CHO-KLAT for five European countries (France, Germany, The Netherlands, Spain, and the United Kingdom). Through this process, changes were made to some of the response options and minor changes were made to some of the items, resulting in the next revision to the CHO-KLAT, the CHO-KLAT version 2.0 (CHO-KLAT v2.0). The CHO-KLAT v2.0 underwent cognitive debriefing, and testing showed it to be valid and reliable for boys with haemophilia (Young et al., Value in Health, 2013). CHO-KLAT v2.0 has subsequently been cross-culturally adapted for use in many regions of the world (for example: Wu et al., Health Qual Life Outcomes, 2012; Young et al., Haemophilia, 2012; Villaça et al., Haemophilia, 2013; McCusker et al., Haemophilia, 2015; Usuba et al., Res Pract Thromb Haemost, 2019).

However, the CHO-KLAT v2.0 was developed before the availability of extended half-life clotting factor concentrates (EHL CFCs), and other non-factor therapies. In a follow-up study, the relevance of the item content of the CHO-KLAT v2.0 was reviewed through a series of focus groups, in the context of EHL CFCs and other emerging therapies. Thirteen focus groups were conducted at five Canadian comprehensive care haemophilia treatment centres (Halifax, Toronto, Hamilton, Ottawa, and Edmonton): five with boys with haemophilia, three with parents, and four with haemophilia health care providers. Based on results of the focus groups, 19 changes were made to the existing items in the CHO-KLAT v2.0 and seven new items were added, resulting in a revised 41item version, CHO-KLAT v3.0 (Price et al., Res Pract Thromb Haemost, 2021). Using the domain framework initially proposed for the CHO-KLAT79 (Young et al., Haemophilia, 2004), and guided by expert consensus, the team developed a revised domain structure for use with the current measure: activities (five items), autonomy (seven items), bleeding (four items), emotional health (four items), haemophilia knowledge (three items), social functioning (nine items), and treatment (eight items). The CHO-KLAT v3.0 is a valid, reliable child-centric tool that is designed to measure HRQoL among boys with haemophilia, and incorporates a subdomain scoring structure to facilitate assessment of concepts important to emerging therapies, such as burden of administration.

References

  1. Young NL, Bradley CS, Blanchette V, Wakefield CD, Barnard D, Wu JK, McCusker PJ. Development of a health‐related quality of life measure for boys with haemophilia: the Canadian Haemophilia Outcomes–Kids Life Assessment Tool (CHO‐KLAT). Haemophilia. 2004 Mar;10:34-43.
  2. Young NL, Bradley CS, Wakefield CD, Barnard D, Blanchette VS, McCusker PJ. How well does the Canadian Haemophilia Outcomes‐Kids’ Life Assessment Tool (CHO‐KLAT) measure the quality of life of boys with haemophilia?. Pediatric blood & cancer. 2006 Sep;47(3):305-11.
  3. Young NL, Wakefield C, Burke TA, Ray R, McCusker PJ, Blanchette V. Updating the Canadian hemophilia outcomes–kids life assessment tool (CHO-KLAT version2. 0). Value in health. 2013 Jul 1;16(5):837-41.
  4. Wu R, Zhang J, Luke KH et al. Cross-cultural adaptation of the CHO-KLAT for boys with hemophilia in rural and urban China. Health Qual Life Outcomes. 2012; 10: 112.
  5. Young NL, St-Louis J, Burke TA, Hershon L, Blanchette V. Cross-cultural validation of the CHO-KLAT and HAEMO-QoL-A in Canadian French. Haemophilia. 2012; 18: 353-437.
  6. McCusker PJ, Burke TA, Holzhauer S et al. International cross cultural validation study of the Canadian Hemophilia Outcomes–Kids Life Assessment Tool (CHO-KLAT). Haemophilia. 2015; 21: 351-357.
  7. Villaça PR, Carneiro JDA, D’Amico EA et al. Process and experience of cross-cultural adaptation of a quality of life measure (CHO-KLAT) for boys with hemophilia in São Paulo, Brazil. Haemophilia. 2013; 19: 861-865.
  8. Usuba K, Price VE, Blanchette V et al. Impact of prophylaxis on health-related quality of life of boys with hemophilia: An analysis of pooled data from 9 countries. Res Pract Thromb Haemost. 2019; 3: 397-404.
  9. Price, VE., et al., Updating the Canadian Hemophilia Outcomes – Kids’ Life Assessment Tool (CHO-KLAT) in the era of extended half-life clotting factor concentrates. RPTH, 2021. 5(3): p. 403-411.