Validation of Patient-Reported Outcome measure in pediatric chronic Kidney disease (PRO-Kid)

Background: Measuring the burden of symptoms that matter most to children and adolescents with chronic kidney disease (CKD) is essential for optimizing patient-centered care. We developed a novel CKD-specific Patient-Reported Outcome measure (PRO-Kid) to assess both frequency and impact of symptoms in children. In the current study, we further assessed the validity and internal consistency of PRO-Kid. Methods: In this multicenter study, children age 8 to 18 years with stages 3-5 CKD, including those on dialysis, were recruited from five pediatric centers. Children completed the 14-item PRO-Kid questionnaire and the validated Pediatric Quality of Life Inventory (PedsQL™ 4.0). We explored the dimensionality of the PRO-kid scale using exploratory and confirmatory factor analysis, to either establish that it is a unidimensional construct or identify evidence of subfactors. We then assessed internal consistency (Cronbach’s alpha [Cα]) and construct validity (Pearson correlations). Results: In total, 100 children were included. The median eGFR was 27.4 ml/min/1.73m2 [7.43, 63.4], and 26 children (26%) were on dialysis. Both the PRO-Kid frequency and the impact scales were unidimensional. Cα was high for both the PRO-Kid frequency and impact scales, 0.83 (95% CI = 0.78 to 0.88) and 0.84 (95% CI = 0.80 to 0.89) respectively, showing strong internal consistency. Pearson correlations between PRO-Kid and PedsQL™ scores were also strong: -0.78 (95% confidence interval [CI] = -0.85 to -0.70) for the frequency score and -0.69 (95% CI = -0.78 to -0.56) for the impact score, reflecting the association between poorer quality of life and higher symptom burden. Conclusions: PRO-Kid is a novel patient-reported symptom burden tool for children 8-18 years of age with CKD that correlates strongly in the expected direction with PedsQL™, supporting its validity. Future work will evaluate changes in PRO-Kid score with progression of CKD, and implementation of the tool into clinical care.