Overestimation and underestimation of youths’ health-related quality of life are associated with youth and caregiver positive screens for depression: results of a population-based study among youths with longstanding type 1 diabetes

BACKGROUND: This study aimed to analyze the extent and direction of disagreement between self- and proxy-reported quality of life (QoL) and the factors associated with QoL overestimation and underestimation by caregivers compared with self-reports. METHODS: This study used data from population-based questionnaire surveys conducted in 2012–2013 and 2015–2016 with 11- to 17-year-olds with a duration of type 1 diabetes of 10 years or longer and their caregivers (n = 1058). QoL in youth was assessed via 10-item KIDSCREEN (KIDSCREEN-10) self- and proxy-reported questionnaires. The scores ranged from 0 to 100, with higher scores indicating better QoL. Depression screening was performed via the Center for Epidemiological Studies Depression Scale for Children for youths (CES-DC screen positive: score > 15) and WHO-5 Well-being Index for parents/caregivers (WHO-5 screen positive: score ≤ 50). RESULTS: The mean self- and proxy-reported normalized KIDSCREEN-10 scores were 64.2 (standard deviation [SD] 11.4) and 66.1 (11.5), respectively. More caregivers overestimated (self-reported minus proxy-reported score < − 0.5*SD self-reported score) than underestimated (self-reported minus proxy-reported score > 0.5*SD self-reported score) youths’ QoL (37% versus 23%, p < 0.001). Youths who screened positive for depression (18%) were at higher risk of their QoL being overestimated and lower risk of their QoL being underestimated by caregivers than youths who screened negative for depression (RR(Overestimation) 1.30 [95% CI 1.10–1.52], RR(Underestimation) 0.27 [0.15–0.50]). Caregivers who screened positive for depression (28%) overestimated the QoL of their children less often and underestimated the QoL of their children more often than caregivers who screened negative for depression (RR(Overestimation) 0.73 [0.60–0.89], RR(Underestimation) 1.41 [1.14–1.75]). CONCLUSIONS: Caregivers often over- or underestimated their children’s QoL. Positive screens for depression among both youths and caregivers contributed to the observed differences between self- and caregiver-reported QoL. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13098-022-00809-w.