Psychometric Properties of the German Version of the Quality of Life after Brain Injury Scale for Kids and Adolescents (QOLIBRI-KID/ADO) Using Item Response Theory Framework: Results from the Pilot Study

Abstract

Health-related quality of life (HRQOL) is an important indicator for recovery after pediatric TBI. To date, there are a few questionnaires available for assessing generic HRQOL in children and adolescents, but there are not yet any TBI-specific measures of HRQOL that are applicable to pediatric populations. The aim of the present study was to examine psychometric characteristics of the newly developed Quality of Life After Brain Injury Scale for Kids and Adolescents (QOLIBRI-KID/ADO) questionnaire capturing TBI-specific HRQOL in children and adolescents using an item response theory (IRT) framework. Children (8–12 years; n = 152) and adolescents (13–17 years; n = 148) participated in the study. The final version of the QOLIBRI-KID/ADO, comprising 35 items forming 6 scales, was investigated using the partial credit model (PCM). A scale-wise examination for unidimensionality, monotonicity, item infit and outfit, person homogeneity, and local independency was conducted. The questionnaire widely fulfilled the predefined assumptions, with a few restrictions. The newly developed QOLIBRI-KID/ADO instrument shows at least satisfactory psychometric properties according to the results of both classical test theoretical and IRT analyses. Further evidence of its applicability should be explored in the ongoing validation study by performing multidimensional IRT analyses.

A Multidimensional Approach to Assessing Factors Impacting Health-Related Quality of Life after Pediatric Traumatic Brain Injury

“…Major depression disorder was assessed using the Patient Health Questionnaire 9 (PHQ-9) [ 48 ] completed by parents, as was the Generalized Anxiety Disorder-7 (GAD-7) [ 49 ]. Self-reported TBI-specific HRQoL was captured using the Quality of Life after Traumatic Brain Injury in Kids/Adolescents (QOLIBRI-KID/ADO) questionnaire [ 50 ]. Details of the instruments can be found in Appendix A —Instruments and measures.…”

Final Validation of the Quality of Life after Brain Injury for Children and Adolescents (QOLIBRI-KID/ADO) Questionnaire

“…Parents rated participants' symptoms on a four-point Likert-type scale ("Not at all" (0) to "Nearly every day" (3)). The severity of the anxiety disorder is represented by the sum score of all the items, which ranges from 0 to 21: minimal (1-4), mild (5-9), moderate (11)(12)(13)(14), and severe (15)(16)(17)(18)(19)(20)(21) anxiety symptoms [34]. The PHQ-9 uses DSM-IV [33] criteria to assess the presence and severity of symptoms related to major depression.…”

“…Parents were asked to rate nine depression symptoms on a four-point Likert-type scale ("Not at all" (0) to "Nearly every day" (3)). The sum score of the items ranges from 0 to 27, leading to the following severity categories: minimal (1-4), mild (5-10), moderate (11)(12)(13)(14), and severe (15-27) symptoms of depression [35].…”

“…Satisfactory construct validity was demonstrated compared to the Pediatric Quality of Life Inventory (PedsQL) [14] as a reference measure of generic HRQoL. Psychometric analyses using an item response theory framework indicated that the scales were largely unidimensional, there was no evidence to suggest that the assumptions of monotonicity and local independence were violated, and for the most part, no DIF occurred in the various patient groups [13].…”

“…The QOLIBRI-KID/ADO consisted of 35 items covering six domains (i.e., Cognition, Self, Daily Life and Autonomy, Social Relationships, Emotions, and Physical Problems). The questionnaire was shown to be reliable and valid in capturing HRQoL in children and adolescents after a TBI [12,13]. Its psychometric properties were examined using methods referred to as the classical test theory (i.e., reliability and validity), supplemented by differential item functioning (DIF) analyses for the age groups.…”