Development of the Oral Health Literacy Profile (OHLP)-Psychometric properties of the oral health and dental health system knowledge scales

Objectives Current oral health literacy (OHL) instruments vary in focus, methodology, administration time and burden. The widely used word recognition tests fail to encompass important OHL domains, while others exceed time frames for use in practical settings, require an interviewer or mainly measure self-assessments. This paper describes the development of the Oral Health Literacy Profile (OHLP), introduces its components and evaluates the psychometric properties of its two core modules, the knowledge tests. Methods A preliminary version of the questionnaire was developed and assessed for content validity, relevance and redundancy by an expert panel. It was tested in a convenience sample (n = 95) leading to the creation of a 28-item questionnaire, which was afterwards tested in a second convenience sample (n = 193). Item difficulty, discrimination, internal reliability and construct validity were assessed for the oral health knowledge (OHK) and dental health system knowledge (DHSK) modules. Results The items showed acceptable range of difficulty (ideal: 7 items; easy: 5 items; and difficult: 3 items) and good to very good discriminatory power (the point-biserial index (PBI) > 0.30: all items). Construct validity was considered to be fulfilled when 75% of the hypotheses of expected group differences were met. Satisfactory internal reliability was observed. Conclusion With all its components, the OHLP is a suitable short instrument to assess the most relevant dimensions of the multifaceted construct of OHL. Practice implication The OHLP can be widely used in research, especially suitable in practical settings, and thereby identify patients who may benefit from oral health education.