Construct Validity and Responsiveness of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales and Infant Scales in the PICU

Objectives: To assess the construct validity and the responsiveness of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales and Infant Scales in the medical-surgical (PICU) and cardiac PICU. Design/Setting/Participants: Prospective cohort study of 367 inpatients admitted either to the PICU or the cardiac ICU at Seattle Children's Hospital from January 2012 to June 2013. Parent/caregiver and child (>= 8 yr old, developmentally appropriate, and critical illness resolved) Pediatric Quality of Life Inventory scores were obtained within 24 hours of PICU/cardiac ICU discharge and subsequently at 4-12 weeks following hospital discharge. Of the 491 eligible participants invited to participate, 367 (74.7% response rate) completed the Pediatric Quality of Life Inventory survey at ICU discharge, and of these, 263 (71.7% follow-up response rate) completed the follow-up survey 4-12 weeks after hospital discharge. Measurements and Main Results: Responsiveness was assessed by calculating improvement scores (difference between follow-up and ICU discharge scores, Lambda Pediatric Quality of Life Inventory). Construct validity was examined by comparing mean improvement scores for known groups differing by medical complexity. At follow-up, Delta Pediatric Quality of Life Inventory scores were as follows (mean +/- sd): physical domain, 34.8 +/- 32.0; and psychosocial domain, 23.1 +/- 23.5. Patients with complex chronic or noncomplex chronic disease had physical functioning improvement scores that were 17.4 points (95% CI, -28.3 to -6.5; p < 0.001) and 19.5 points (95% CI, -30.4 to -8.5; p < 0.002) lower than children with no chronic illness, respectively. Patients with complex chronic disease exhibited psychosocial improvement scores that were 9.6 points (95% CI, -18.4 to -0.8; p < 0.033) lower than patients without chronic disease. Patients with noncomplex chronic disease had similar psychosocial improvement scores when compared with patients without chronic disease. Conclusions: As a measure of health-related quality of live, Pediatric Quality of Life Inventory demonstrated responsiveness and construct validity in a broad population of critically ill children. This measure represents a patient-centered clinically meaningful patient-or-parent-reported outcome measure for pediatric research assessing the clinical effectiveness of PICU/cardiac ICU interventions. When using health-related quality of life recovery as an outcome measure to assess clinical effectiveness in the PICU/cardiac ICU setting, measuring and controlling for the level of medical complexity is important in order to understand the true impact of clinical interventions.