Evaluating quality of life in children with cancer using children's self-reports and parent-proxy reports

Background. Assessment of quality of life (QOL) of children is complex due to the developmental differences in understanding the content being measured. The validity of parent-proxy reports versus children's self-reports remains to be clarified. Objectives: To examine the agreement on QOL measures between children's self-reports and parent-proxy reports at different points in time, including at baseline and at 6-month follow up, as well as the change in scores between 6-month follow up and baseline. Method. A longitudinal study of QOL assessment of children with cancer for parents and children was conducted. At baseline assessment, 126 children with cancer and at least one of their parents participated (n = 252). Forty boys, 25 girls, and their parents (n = 130) completed the 6-month follow up assessment. Results: Parents tended to report better QOL than did the children at both baseline and 6-month follow up assessments in both the on- and off-treatment groups. Agreement on QOL measure between children and parent proxies varied as a result of the following factors: treatment status (on and off treatment), time (at baseline vs. at 6-month follow up), and changes in score between the time of the baseline assessment and the 6-month follow up. The effects of time, age, gender, and severity of illness had different degrees of significance as predictors on various subscales. Discussion: The predictors of agreement between patients' reports and parent-proxy reports, including the passage of time (from baseline to 6-month follow up), gender, age, and illness severity, have not been conclusively determined. Further studies are needed to examine patient-proxy agreement during a longer follow up period at more than two points in time and using the same patients through the stages of confirmation of diagnosis, acceptance of diagnosis, treatment, and after treatment.