Challenges to the measurement of health-related quality of life in children receiving cancer therapy.

Measures of health-related quality of life (HRQL) assess those areas of a patient's functioning that are affected by their cancer and its therapy. Although HRQL measures are integrated frequently into studies of survivors of childhood cancer, their use in the assessment of children receiving therapy has been limited by several methodological challenges. These arise from issues specific to measuring HRQL in young children, who comprise a large proportion of the pediatric oncology population, and from issues associated with assessing HRQL during therapy, when the patient's health status is in constant flux. This study summarizes the commonly used HRQL measures, and examines factors that impact their broad application. These include the influence of developmental changes on the content and format of HRQL measures, the role of proxy assessors, the important characteristics of measurement tools used to assess patients receiving active therapy, and the issues related to the ideal timing of serial HRQL assessments in prospective trials. Copyright 2004 Wiley-Liss, Inc.