Assessing paediatric health-related quality of life within a cross-cultural perspective: Semantic and pilot validation study of the Portuguese versions of DISABKIDS-37

The aims of this study were to validate semantically the Portuguese versions of DISABKIDS-37 (quality of life questionnaires for children and adolescents with chronic conditions) and to explore their psychometric performance in a pilot study. For each health condition (asthma and epilepsy), groups of children (aged 8-12 years) and adolescents (aged 13-18 years) were formed, including nine individuals and their parents (total = 72 subjects), to whom the Portuguese versions of DISABKIDS-37 and the semantic validation questionnaires were administered. Data on symptom severity were obtained from parents' reports. The study also included a sample of 18 teachers with experience in teaching youths with chronic conditions. Results of semantic validation supported the relevance, comprehensibility and adequacy of the Portuguese versions. Internal consistency ranged between 0.84 and 0.92 for the self-reported version and 0.78 and 0.92 for the proxy-reported version. Correlations between facets and domains were mainly strong (0.61-0.77) and very strong (0.82-0.87). Self-and proxy-reported health-related quality of life (HRQoL) was lower for the epilepsy group (social domain), and proxy-reported HRQoL (physical limitation facet) was poorer for the asthma group. Adolescents reported higher levels of HRQoL than children, and parent-child concordance was weak. These results reaffirm that semantic and exploratory validation procedures are important to achieve adequate levels of equivalence between different versions of HRQoL questionnaires.