Development of KROHL, a tool for evaluating oral health knowledge

OBJECTIVES: The authors aim to evaluate a scale assessing oral health knowledge, the KROHL (Knowledge Related to Oral Health Literacy) including the inter-rater reliability for scoring open-ended questions, internal consistency of the hypothesized scales, the discriminant validity of the resulting scale and its relationship to existing measures of oral health literacy. METHODS: The questionnaire was administered via face-to-face interviews to 144 volunteers recruited in the waiting areas of clinics throughout the NYU College of Dentistry. The KROHL questionnaire evaluates oral health knowledge by asking open-ended questions about the appearance, cause, treatment and prevention of caries, gum disease, oral cancer, tooth loss and malocclusion. Those 20 questions were scored to produce scale scores. Demographic information, a self-reported measure of HL and the CMOHK (Comprehensive Measure of Oral Health Knowledge) were also collected. Data were analyzed using Pearson correlation coefficients and principal components analysis, by computing Cronbach's alpha and Cohen's kappa, and by comparing group means with ANOVA. RESULTS: Kappa indicated good to excellent agreement among raters for the full and the individual subscales of the KROHL. Cronbach's alpha indicated good consistency of the full scale score, but not the individual scales. The mean (SD) KROHL score was lower in the patient group than in the dental students (13.3 (5.9) vs. 26.1 (4.7), p < .001), and varied directly with education level within the patients. KROHL scores were unrelated to existing measures of health literacy. CONCLUSIONS: The KROHL scale is an innovative, reliable and valid tool to assess overall oral health knowledge and provide information to customize educational interventions. Further research is needed to determine the validity and reliability of the scale in multiple settings. INNOVATION: The innovation of the KROHL tool of assessment of oral health knowledge lies in its ability to scale depth of knowledge within the domains of identification, causes, prevention, and treatment for the most common oral conditions.