Quality of Life Assessment in Spina Bifida for Children (QUALAS-C): Development and Validation of a Novel Health-related Quality of Life Instrument

Abstract

Objective To develop and validate a self-reported health-related QUAlity of Life Assessment in Spina bifida for Children (QUALAS-C). Methods We drafted a 27-question pilot instrument using a patient-centered comprehensive item generation and refinement process. It was administered to a sample of children 8-12 years old with spina bifida (SB) recruited online via social media and in person at an outpatient SB clinic (January 2013-September 2014). Healthy controls were recruited at routine pediatrician visits. Validation and final questions were determined based on clinical relevance, high loadings on factor analysis, and domain psychometrics. Children with SB also completed the validated generic Kidscreen-27 instrument. Results Median age of 150 participants was 9.6 years (60.7% male, 72.7% Caucasian), similar to 46 controls (P ≥ .10). There were 97 online and 53 clinic participants (89.0% and 84.2% of eligible, respectively). Face and content validities of the 2-domain, 10-question QUALAS-C were established by patients, parents, and experts. Internal consistency and test-retest reliability was high for the Esteem & Independence and Bladder & Bowel domains (Cronbach's alpha: 0.72-0.76, ICC: 0.74-0.77). Correlations between QUALAS-C domains were low (r = 0.51), indicating that QUALAS-C can differentiate between two distinct health-related quality of life components. Correlations between QUALAS-C and Kidscreen-27 were also low (r ≤ 0.44). QUALAS-C scores were significantly lower in children with SB than without (P < .0001). Conclusion QUALAS-C is a short, valid health-related quality of life tool for children with SB. It will be useful in clinical and research settings.