Development and psychometric validation of the orthodontic health literacy tool

Over the past few years, there has been increasing emphasis on context-specific health literacy. However, no such context-specific psychometric tools are available with regard to oral health literacy. The aim of this study was to develop and validate an Orthodontic Health Literacy Tool (Orth-HLT).

After development of initial item pool, the items were assessed for content validity. The final tool consisted of 22 items in the four domains of functional, communicative, critical orthodontic health literacy, and orthodontic knowledge. Orth-HLT was administered to a convenience sample of 642 subjects. The data were subjected to exploratory and confirmatory factor analyses using IBM SPSS Version 20.0 software and IBM SPSS Amos 26.0, respectively. Pearson's correlation, independent samples t-test, and one-way analysis of variance were performed.

Orth-HLT demonstrated good face and content validity. The domain-specific internal consistency reliability values were optimal. Exploratory factor analysis on the items in all four domains resulted in a single factor solution. Four models were evaluated in the confirmatory factor analysis; the correlated factors model showed best model fit indices. Each domain of Orth-HLT showed moderate to strong positive correlation with Indian Oral Health Literacy Measure in Telugu indicating the convergent validity of the tool.

Orth-HLT is the first context-specific oral health literacy tool and demonstrates strong psychometric properties, which could be used to evaluate orthodontic health literacy and articulate orthodontic health education materials in an informed manner.