Evaluation of a word recognition instrument to test health literacy in dentistry: The REALD-99

Objective: This study aims to evaluate a dental health literacy word recognition instrument. Methods: Based on a reading recognition test used in medicine, the Rapid Estimate of Adult Literacy in Medicine (REALM), we developed the Rapid Estimate of Adult Literacy in Dentistry (REALD-99). Parents of pediatric dental patients were recruited from local dental clinics and asked to read aloud words in both REALM and REALD-99. REALD-99 scores had a possible range of 0 (low literacy) to 99 (high literacy); REALM scores ranged from 0 to 66. Outcome measures included parents' perceived oral health for themselves and of their children, and oral health-related quality of life of the parent as measured by the short-form Oral Health Impact Profile (OHIP-14). To determine the validity, we tested bivariate correlations between REALM and REALD-99, REALM and perceived dental outcomes, and REALD-99 and perceived dental outcomes. We used ordinary least squares regression and logit models to further examine the relationship between REALD-99 and dental outcomes. We determined internal reliability using Cronbach's alpha. Results: One hundred two parents of children were interviewed. The average REALD-99 and REALM-66 scores were high (84 and 62, respectively). REALD-99 was positively correlated with REALM (PCC = 0.80). REALM was not related to dental outcomes. REALD-99 was associated with parents' OHIP-14 score in multivariate analysis. REALD-99 had good reliability (Cronbach's alpha = 0.86). Conclusions: REALD-99 has promise for measuring dental health literacy because it demonstrated good reliability and is quick and easy to administer. Additional studies are needed to examine the validity of REALD-99 using objective clinical oral health measures and more proximal outcomes such as behavior and compliance to specific health instructions.