Linguistic validation of a disease-specific quality of life measure for children and teenagers with cardiac disease.
INTRODUCTION
To anglicise an American--that is, English language--disease-specific health-related quality of life measure, using the Paediatric Cardiac Quality of Life Inventory, for children in the age group of 8-12 years and adolescents in the age group of 13-18 years with cardiac disease, and to assess conceptual equivalence of the American and British versions.


METHODS
A process of forward and backward translation of the measure was undertaken before focus groups and individual interviews with 40 participants--that is, 20 children/adolescents with cardiac disease and 20 parents of children/adolescents with cardiac disease--to determine their understanding of the meaning of the questions.


RESULTS
Interviews established that participants understood the meaning of the questions, although some found it difficult to explain the meaning of questions in which the language was explicit and wanted instead to answer the individual questions as they applied to them/their child. There was agreement that all versions of the questionnaire were relevant and comprehensive, and that the length of the questionnaires was acceptable and practical.


CONCLUSIONS
The anglicised version of the Paediatric Cardiac Quality of Life Inventory appears to be a linguistically valid measure of health-related quality of life for children and adolescents with cardiac disease. The psychometric properties of the anglicised Paediatric Cardiac Quality of Life Inventory are now being tested in a multi-centre study in the United Kingdom.