Responsiveness of the Italian version of the Pediatric Quality of Life Multidimensional Fatigue Scale in adult inpatients with obesity

This study aimed to evaluate the responsiveness of the Italian version of the Paediatric Quality of Life Inventory Multidimensional Fatigue Scale (PedsQL-MFS) to changes in BMI, fatigue and depressive symptoms in adult inpatients with obesity. 198 adults (81% female, mean age = 44.7 years) with obesity completed the PedsQL-MFS, the Fatigue Severity Scale (FFS) and the Centre for Epidemiologic Studies Depression Scale (CESD) before and after completing a 3-week body weight reduction program. Internal responsiveness was measured via paired t-tests, standardized mean response (SMR) and Glass's delta (d). Changes in FFS, CESD and BMI were used as anchors to categorize participants as "improved", "unchanged" or "deteriorated". External Responsiveness was assessed by comparing mean post-intervention PedsQL-MFS scores across change groups, adjusting for pre-intervention PedsQL-MFS scores and in area-under-curve (AUC) analysis. PedsQL-MFS Total, Sleep/Rest Fatigue and Cognitive Fatigue scores demonstrated significant reductions in response to an established body weight reduction program. Post-intervention PedsQL-MFS scale scores were lower among those who had improved on the CESD and FSS than among those whose CESD and FSS scores had not significantly changed. There was no difference in PedsQL-MFS scale scores according to whether participants had reduced their BMI by at least 5%. AUC analyses indicated that change in PedsQL-MFS scores was somewhat more predictive of improvement in CESD than FSS scores. The Italian version of the PedsQL-MFS demonstrated both internal and external responsiveness. It appeared more sensitive to improvement than deterioration in fatigue symptoms and its sensitivity to deterioration in depressive symptoms and weight loss could not be evaluated in the present study as there was no reliable deterioration in CESD scores and weight loss was modest. Future studies should include a control group to assess the sensitivity of the PedsQL-MFS more thoroughly.