Parent knowledge of disease management in cystic fibrosis: Assessing behavioral treatment management

Background: Cystic fibrosis (CF) is a life-shortening, burdensome disease requiring complex knowledge to manage the disease. Significant gaps in knowledge have been documented for parents, which may lead to unintentionally poor adherence and insufficient transfer of treatment responsibility from parents to adolescents. There are no current, validated measures of parent knowledge for this population and there are no measures that assess the knowledge required for day-to-day behavioral management of CF. We assessed the psychometric properties of the parent version of the Knowledge of Disease Management-Cystic Fibrosis measure (KDM-CF-P) using data from iCARE (I Change Adherence and Raise Expectations), a randomized control adherence intervention trial. Methods: A total of 196 parents in the iCARE standard care/control arm completed 35 items assessing their knowledge of disease management at their 12-month study visit, prior to beginning the intervention. Items were eliminated from the measure if they met the threshold for ceiling effects, were deemed clinically irrelevant, or did not correlate well with their intended scale. Item-to-total correlations, confirmatory factor analysis, discriminant function, reliability, and convergent validity were calculated. Results: The KDM-CF-P (19 items) demonstrated internal consistency of KR20 = 0.60 on each scale and a two-scale structure. Convergent validity for knowledge scores was found with maternal education, family income, and type of medical insurance. Parents correctly answered approximately 85% of items on the KDM-CF-P. Conclusions: The KDM-CF-P psychometrics support a two-scale measure with clinical utility. It is useful for assessing gaps in knowledge that can be remediated through individualized, tailored interventions.