Comparing longitudinal assessments of quality of life by patient and parent in newly diagnosed children with cancer: The value of both raters' perspectives
Health-related quality of life (HRQoL) information from children facing rare and/or life-threatening disease serves important clinical functions. Longitudinal HRQoL ratings from 222 child-parent dyads collected at four time points during the first 16 weeks of cancer treatment are presented. Patient and parent HRQoL reports at the domain level, based on the Pediatric Quality of Life Inventory™ 4.0 Generic Core Scales, were compared over time, and variation in child/parent agreement by age, treatment intensity, and time on treatment was explored. Analyses included consideration of missingness, differences between child and parent group mean domain scores averaged over assessments, agreement between individual child and parent, compared to group averages, and within-subject changes between assessments. Children consistently reported higher functioning than their parents with differences varying by child age and HRQoL domain and diminishing over time. No differences were found by intensity of treatment. The between-subject correlation ranged from 0.61 (social functioning) to 0.86 (physical functioning) across time. Agreement within groups, defined by age, treatment intensity, and time were generally similar. Results indicate moderate-to-good child/parent agreement with variability by domain of HRQoL. Findings underscore the complexity of self- and proxy-based report and support the use of information from both raters.