International child health. Measuring health-related quality of life in a child population

Abstract

Background: The 56-item TNO AZL Child Quality Of Life (TACQOL) questionnaire was developed to meet the need for a reliable and valid instrument for measuring health-related quality of life (HRQoL) in children. HRQoL was defined as health status in seven domains plus emotional responses to problems in health status. The TACQOL explicitly offers respondents the possibility of differentiating between their functioning and the way they feel about it. The aims of the study were threefold: to evaluate psychometric performance of the TACQOL in the general population, to evaluate the relationship between Parent Forms and Child Forms and to obtain additional information about validity. Methods: A random sample of 1,789 parents of 6–11 year olds completed the TACQOL (response rate 71%), as well as 1,159 8–11 year olds themselves (response rate 69%). Results: Multiple correspondence analyses showed that item response categories were ordinal and that the TACQOL scales may be regarded as metric. Cronbach's α ranged from 0.65 to 0.84. Only 57% of reported health status problems were associated with negative emotions. Intraclass correlation coefficients between Parents Forms and Child Forms ranged from 0.44 tot 0.61. Pearson's correlation coefficients between TACQOL and KINDL ranged from 0.24 to 0.60. Univariate analyses of variance showed that children with chronic diseases and children receiving medical treatment had lower TACQOL scores than healthy children. Conclusions: The study showed that with the TACQOL, children's HRQoL can be measured in a reliable and valid way.