Development and Validation of a Tool to Assess Disease-Related Knowledge in Children with Coeliac Disease

<b>Background/Objectives:</b> Assessment of disease-specific knowledge levels among children with coeliac disease (CD) is essential to support self-management of their condition. A suitable knowledge assessment tool has not yet been identified that is appropriate for children. The aim of this study was to develop and validate a tool for this purpose. <b>Materials and Methods:</b> Using content synthesis of available literature, a CD knowledge assessment tool (CD-Know) was developed to include items shown to be relevant to the management of CD for children. CD-Know went through development stages of expert review, two rounds of pilot/validation testing, and item response analysis. CD-Know scores were compared between participant groups using a univariate linear model. <b>Results:</b> CD-Know was developed using content synthesis and review by international CD experts. CD-Know was initially piloted among adults/children with CD (<i>n</i> = 12) and underwent the first validation study (<i>n</i> = 330 participants) among adults/children with CD, cohabitants, healthcare professionals (HCPs), and groups without CD. Based on item response analysis the tool was modified. The phases of the pilot (<i>n</i> = 7) and validation studies were repeated among refined groups (<i>n</i> = 230). The final 15-item CD-Know demonstrated an appropriate hierarchy of knowledge between testing groups. Children with CD scored lower than cohabitants of someone with CD (mean difference (MD) -3.0, SD 0.4, <i>p</i> < 0.001) and HCPs (MD -1.7, <i>p</i> = 0.009), at a similar level to adults without CD (MD 0.6, <i>p</i> = 0.88), and higher than children without CD (MD 5.8, <i>p</i> < 0.001). The CD-Know score of children with CD was positively associated with their adherence level to a gluten-free diet (R 0.30, <i>p</i> = 0.017). Test-retest reliability had a good intraclass correlation coefficient (R 0.73, <i>p</i> = 0.003). Internal consistency was good (Cronbach's alpha 0.71). <b>Conclusions:</b> CD-Know is a validated tool to assess disease-related knowledge in children diagnosed with CD. Its potential applications include identifying areas for knowledge enhancement within the population and assessment of CD interventions.