Development of the Chinese version of the Paediatric Allergic Disease Quality of Life Questionnaire: reliability and validity.

Objective: Paediatric Allergic Disease Quality of Life Questionnaire is a health-related assessment tool designed for children with allergic diseases. This study aimed to translate the original English version of the Questionnaire to Chinese and to provide psychometric evidence on the validity and reliability of the translated version.
Design: Cross-sectional study.
Setting: Out-patient clinic of a non-teaching hospital in Hong Kong.
Participants: The Paediatric Allergic Disease Quality of Life Questionnaire was translated to Chinese and then completed by a group of 115 Hong Kong Chinese children (66 male and 49 female; mean age, 11 years) with allergic disease(s). All subjects were asked to respond using visual analogue scales dealing with issues related to the perceived morbidity of allergic diseases. To assess test-retest reliability, 2 weeks later a subgroup of 16 individuals was retested with the same Questionnaire.
Results: The internal consistency of the Chinese Paediatric Allergic Disease Quality of Life Questionnaire was satisfactory (Cronbach alpha=0.92). The correlation between the total Questionnaire score and the visual analogue scale score was moderately significant (Spearman's rho=0.49; 95% confidence interval, 0.34-0.62). Structural validity as studied by confirmatory factor analysis found that the structure of subscales was remarkably similar to the original English version. The intra-class correlation between the Questionnaire score from the first and the second test in the subgroup of 16 subjects was 0.75, indicating adequate repeatability.
Conclusion: The validity and reliability of the Chinese version of the Paediatric Allergic Disease Quality of Life Questionnaire was established for clinical use.