Head-to-head comparisons of quality of life instruments for young adult survivors of childhood cancer
Menée aux Etats-Unis, cette étude analyse et compare l'efficacité de deux outils permettant de mesurer la qualité de vie de jeunes survivants adultes d'un cancer pédiatrique
Purpose Few studies examine the relevance of health-related quality of life (HRQOL) instruments for young adult survivors of childhood cancer (YASCC). This study compared the psychometric properties of two survivor-specific instruments, the Quality of Life–Cancer Survivor (QOL-CS) and Quality of Life in Adult Cancer Survivor (QLACS). Methods Data from 151 YASCC who enrolled in cancer/tumor registries of two medical centers were used. We examined construct validity by conducting confirmatory factor analysis using indices of chi-square statistic, comparative fit index, and root mean square error of approximation. We examined convergent/discriminant validity by comparing Pearson’s correlation coefficients of homogeneous (e.g., physical functioning and pain) of both instruments versus heterogeneous domains (e.g., physical and psychological functioning). We assessed known-groups validity by examining the extent to which HRQOL differed by late effects and comorbid conditions and calculated relative validity (RV) defined as contrasting F -statistics of individual domains to the domain with the lowest F -statistic. Superior known-groups validity is observed if a domain of one instrument demonstrates a higher RV than other domains of the instruments. Results YASCC data cannot replicate the constructs both instruments intend to measure, suggesting poor construct validity. Correlations of between-homogeneous and between-heterogeneous domains of both instruments were not discernible, suggesting poor convergent/discriminant validity. Both instruments were equally able to differentiate HRQOL between YASCC with and without late effects and comorbid conditions, suggesting similar known-groups validity. Conclusions Neither instrument is superior. Item response theory is suggested to select high-quality items from different instruments to improve HRQOL measure for YASCC.