International cross-cultural validation study of the Canadian haemophilia outcomes: kids' life assessment tool.

Health-related quality of life (HRQoL) assessment is recognized as an important outcome in the evaluation of different therapeutic regimens for persons with haemophilia. The Canadian Haemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) is a disease-specific measure of HRQoL for 4 to 18-year-old boys with haemophilia. The purpose of this study was to extend this disease-specific, child-centric, outcome measure for use in international clinical trials. We adapted the North American English CHO-KLAT version for use in five countries: France, Germany, the Netherlands, Spain and the United Kingdom (UK). The process included four stages: (i) translation; (ii) cognitive debriefing; (iii) validity assessment relative to the PedsQL (generic) and the Haemo-QoL (disease-specific) and (iv) assessment of inter and intra-rater reliability. Cognitive debriefing was performed in 57 boys (mean age 11.4 years), validation was performed in 144 boys (mean age 11.0 years) and reliability was assessed for a subgroup of 64 boys (mean age 12.0 years). Parents also participated. The mean scores reported by the boys were high: CHO-KLAT 77.0 (SD = 11.2); PedsQL 83.8 (SD = 11.9) and Haemo-QoL 79.6 (SD = 11.5). Correlations between the CHO-KLAT and PedsQL ranged from 0.63 in Germany to 0.39 in the Netherlands and Spain. Test-retest reliability (concordance) for child self-report was 0.67. Child-parent concordance was slightly lower at 0.57. The CHO-KLAT has been fully culturally adapted and validated for use in five different languages and cultures (in England, the Netherlands, France, Germany and Spain) where treatment is readily available either on demand or as prophylaxis.

A survey of children's acute, recurrent, and chronic pain: validation of the pain experience interview.

The ultimate objective of our epidemiological research is to complete a longitudinal population-based study to document the prevalence and impact of acute, recurrent, and chronic pain in children and adolescents. As the first phase of our epidemiological research, we developed a comprehensive screening instrument for identifying children with acute, recurrent, and chronic pain, the Pain Experience Interview. We designed this interview to provide information about the lifetime and point prevalence of various pains, and also to provide information about the intensity, affect, duration, and frequency of children's pain. The primary objective of this study was to validate the Pain Experience Interview using the discriminant validation procedure of group differences. The secondary objectives of our study were to obtain descriptive data on children's acute, recurrent, and chronic pain experiences and to conduct exploratory analyses on age- and gender-related differences in children's pain experiences. We interviewed 187 children from five different health groups (arthritis, cancer, enuresis, recurrent headaches, and healthy) to provide distinct subsets of children with respect to their acute, recurrent, and chronic pain experience, and from four different age groups (5-7, 8-10, 11-13, and 14-16 years) to provide distinct subgroups with respect to children's developmental level. To test the interview we determined a priori several study predictions about children's pain experiences. These included four predictions about the common response patterns that we would expect to observe for all children based on our understanding of acute pain caused by trauma/disease, and six predictions about the distinct response patterns that we would expect to observe based on the known differences among children in their experiences of headache, acute treatment-related pain, recurrent pain, and chronic pain. All study predictions were confirmed, demonstrating that the Pain Experience Interview is a valid screening instrument for differentiating children with different types of pain problems. The interview can provide estimates for the lifetime and point prevalence of various pains in children, and data on the intensity, affect, duration, and frequency of their pain experiences.

Comparing two measures of quality of life for children with haemophilia: the CHO-KLAT and the Haemo-QoL.

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.

Development of a health-related quality of life measure for boys with haemophilia: the Canadian Haemophilia Outcomes--Kids Life Assessment Tool (CHO-KLAT).

Several measures of quality of life (QoL) are available for children with haemophilia. However, most are not disease-specific and few focus on children's perspectives. The purpose of this study was to develop a psychometrically sound measure of QoL that included the perspectives of boys with haemophilia. A list of potential items was developed from the literature, other measures, and input from five discussion sessions with adults with haemophilia, children with haemophilia and their parents and haemophilia nurses. The list was augmented with items generated by three focus groups with children and three focus groups with parents. These groups also prioritized items and recommended a domain structure. Supplemental information was gathered by surveying haematologists. Data from all sources were analysed to reduce the number of items using a two-step approach, based on rules that weighted the children's priorities most heavily. The remaining items were compiled into a questionnaire that was pilot tested with 10 children and their parents. The total item pool contained 228 potential items. Of these, 33 were removed based on three focus groups and survey responses, 72 were removed after the completion of all focus groups and 46 were removed due to redundancy. This resulted in a 77-item version of the CHO-KLAT. Pilot testing identified the need to subdivide two items, resulting in a 79-item CHO-KLAT. The CHO-KLAT is a promising disease-specific measure of QoL that reflects children's unique perspectives. This child-centric focus distinguishes the CHO-KLAT from alternative measures of QoL. Further research will assess the measurement properties of the CHO-KLAT.