American Journal of Ophthalmology, April 2019
In previous research based on interviews, Hatt et al. identified children’s concerns about functional vision and eye-related quality of life (ER-QOL). In a new study, these authors applied the patient-derived concerns to a different cohort of patients, with the goal of developing FDA-compliant questionnaires and testing their validity. This approach proved effective for devising questionnaires that separately assess the domains of functional vision and ER-QOL in children of any age, with any eye condition. (In subsequent research, the authors will test the reliability, construct validity, and responsiveness of these tools.)
The researchers’ goal was to create short forms that represent individual, analysis-driven, unidimensional domains within the separate constructs of functional vision and ER-QOL, for use in any clinical setting. The researchers enrolled 444 children (0 to <18 years of age) from two centers, with the children representing 10 diagnostic categories.
Parents filled out a master questionnaire and proxy questionnaires for their children. Younger children had questions read to them; older children were given forms to fill out. Factor analysis was applied to identify unidimensional domains, and Rasch analyses (differential item functioning, targeting, fit) were performed to reduce the number of items. Rasch lookup tables were used for scoring, and the data were analyzed separately by age group and for each factor.
The number of items per questionnaire/proxy ranges from 29 to 42. The form for the youngest children (0-4 years) consists of three domains: functional vision, bothered by eyes/vision, and social. For ages 5-11 and ages 12-17, the forms include four unidimensional domains: functional vision, bothered by eyes/vision, social, and frustration/worry.
For parents, the master questionnaire includes four domains: impact on parent/family, worry about child’s eye condition, worry about child’s self-perception and interactions, and worry about child’s visual function. The number of domains on parental proxy forms vary according to the age of the child.
Next steps include testing the reliability and validity of the new questionnaires in another cohort of patients.
The original article can be found here.