Oral health literacy and oral health outcomes in an adult population in Brazil

Background: To investigate the association between critical and communicative oral health literacy (OHL) and oral health outcomes (status, oral health-related quality of life and practices) in adults. Methods: This cross-sectional study examined a household probability sample of 248 adults, representing 149,635 residents (20-64 years old) in Piracicaba-SP, Brazil. Clinical oral health and socioeconomic and demographic data, as well as data on oral health-related quality of life (OHIP-14) and health practices were collected. The oral examinations were carried out in the participants' homes, using the World Health Organization criteria for oral diseases. The critical and communicative OHL instrument was the primary independent variable, and it was measured using five Likert items that were dichotomized as 'high' ('agree' and 'strongly agree' responses for the 5 items) and 'low' OHL. Binary and multinomial logistic regressions were performed on each outcome (oral health status and practices), controlling for age, sex and socioeconomic status (SES). Results: Approximately 71.5% presented low OHL. When adjusted for age and sex (first model) low OHL was associated with untreated caries (Odds Ratio = 1.92, 95% Confidence Interval = 1.07-3.45), tooth brushing < 3 times a day (OR = 2.00, 1.11-3.62) and irregular tooth flossing (OR = 2.17, 1.24-3.80). After SES inclusion in the first model, significant associations were found for low OHL when the outcomes were: presence of biofilm (OR = 1.83, 1.08-3.33), dental care for emergency only (OR = 2.24, 1.24-4.04) and prevalence of oral health impact on quality of life (OR = 2.06, 1.15-3.69). Conclusion: Adjusting for age, sex and SES, OHL is related to a risk factor (biofilm) and a consequence of poor oral health (emergency dental visits) and can interfere with the impact of oral diseases on quality of life. As low OHL can be modified, the results support oral health promotion strategies directed at improving critical and communicative oral health literacy in adult populations.