Updating the Canadian Hemophilia Outcomes–Kids Life Assessment Tool (CHO-KLAT Version2.0)

Objectives

Hemophilia is an X-chromosome–linked disorder associated with recurrent bleeding into muscles and joints, leading to pain and limitations in physical function that may diminish quality of life. The Canadian Hemophilia Outcomes–Kids Life Assessment Tool (CHO-KLAT) is a disease-specific measure of quality of life that was recently revised to facilitate cross-cultural adaptation. This study assessed the validity and reliability of version 2.0 of the CHO-KLAT (CHO-KLAT ).

Methods

Content validity was assessed via detailed cognitive debriefing to confirm that Canadian boys understood the CHO-KLAT . The measurement properties of the CHO-KLAT were assessed in comparison to those of the PedsQL, the Haemo-QoL, and two global ratings. Most children completed the CHO-KLAT a second time to assess test-retest reliability.

Results

Cognitive debriefing was completed with 12 boys (age 8.6–17.8 years) and 9 of their parents and resulted in no substantive changes. Sixty boys (mean age 11.8 years) participated in the validation phase, which showed a mean CHO-KLAT score of 75.4±12.0, strong correlations with the PedsQL (r = 0.62, P0.001), and moderate correlations with global ratings of hemophilia bother (ρ =−0.39, P = 0.002) and health (ρ =−0.47, P = 0.0002). Test-retest concordance was better among parents (0.79) than among boys (0.63).

Conclusions

This study establishes the measurement properties of the CHO-KLAT . The summary scores are very similar to those from the original development study, and thus, these have not been affected by the revisions. These results provide reference standards for comparing data from other countries to the Canadian experience and to estimate sample sizes for future clinical trials.