Alumni

Background: Oral diseases are a crucial component of the non-communicable disease spectrum and significantly burden older populations. Along with the rapid increase in the older population worldwide and the anticipated changes in Vietnam’s aging population structure over the next decade, promoting oral health is essential to advancing healthy aging. Oral health literacy (OHL) is a multidimensional construct associated with oral care behaviors (OHBs) and is a key determinant of oral outcomes. However, the global estimate of insufficient OHL and its risk factors among older adults has not been systematically analyzed. Additionally, a validated instrument to assess OHL in the Vietnamese senior population is lacking, and the underlying causal pathways among OHL, OHBs, social support, and self-efficacy remain unclear.

Objectives: to investigate the global prevalence and risk factors associated with insufficient OHL among older adults (study 1). To conduct a cross-cultural adaptive translation and psychometric evaluation of the Vietnamese version of the Health Literacy in Dentistry-14 (HeLD-Vi) among community-dwelling older adults in Vietnam (study 2). To explore the moderating role of self-efficacy on the mediating effect of OHL on the relationship between social support and OHBs (study 3).

Methods: Study 1: Five databases were systematically searched for relevant observational articles from inception to February 2025, with no restriction on language or time of publication. Comprehensive Meta-analysis software was used to conduct a meta-analysis with 95% confidence intervals. The study’s protocol was registered in the PROSPERO database (CRD42024576967). Study 2: A four-stage translation and cultural adaptation process was initially undertaken, followed by a cross-sectional psychometric evaluation conducted among 455 community-dwelling older adults between July and November 2024. Internal reliability was assessed via the Intraclass Correlation Coefficient (ICC) and Cronbach’s alpha. Validity of the HeLD-Vi was evaluated through content, convergent, discriminant, and construct validity, which were examined using Exploratory and Confirmatory Factor Analysis. Study 3: A multistage sampling method was used to recruit 1185 community-dwelling older adults for a cross-sectional study conducted between November 2024 and March 2025. The WHO Basic Methods for Oral Health Survey was used to assess OHBs; OHL was assessed using the Vietnamese version of the Health Literacy in Dentistry-14 (HeLD-Vi); the General Self-Efficacy Scale was used to evaluate self-efficacy; and the Multidimensional Scale of Perceived Social Support was used to assess social support. The PROCESS macro version. 4.0 with the bias-corrected bootstrapping method with a 95% confidence interval (CI) was used to analyze the mediation and moderated mediation association among the study’s variables.

Results: Study 1: Among 1881 identified studies, 13 articles were included in the meta-analysis. The pooled results comprised 4,305 participants, of whom approximately 51.1% (95% CI = 0.39, 0.64) had insufficient OHL. Substantial variability in inadequate OHL was observed across continental regions. The pooled prevalence of inadequate OHL was 60.7% in Asia and 23.2% in non-Asian countries. However, no significant difference in insufficient OHL was observed across different institutional settings and measurement tools. Older age (> 74 years) (pooled odds ratio (OR) = 1.77; 95% CI = 1.23, 2.54) and low educational level (pooled OR = 2.75; 95% CI = 1.87, 4.05) were significant risk factors for insufficient OHL. Publication bias was not detected in this study. Study 2: The HeLD-Vi retained its four-subscale structure and explained a high proportion of variance (83.59%). Reliability analysis demonstrated excellent internal consistency, with an ICC of 0.989 and a Cronbach’s alpha of 0.872. Among the three tested construct models, Model 2, which included covariances, showed the best fit and demonstrated good construct validity. The HeLD-Vi demonstrated stronger correlations with oral health behaviors (r = 0.565, p < 0.01) and oral health-related quality of life (r = 0.506, p < 0.01), supporting convergent validity, and low correlations with social support (r = 0.245, p < 0.01) and self-efficacy (r = 0.260, p < 0.01), confirming discriminant validity. The HeLD-Vi score was significantly associated with educational level, living conditions, and alcohol consumption. Study 3: The study sample had a mean age of 71.3 years (SD = 8.66) and an average OHBs score of 4.78 (SD = 1.54), with significant associations observed between these behaviors and age, living condition, educational level, and alcohol consumption (p < 0.001). Mediation analysis indicated that OHL partially facilitated the relationship between social support and OHBs (β = 0.0145, 95% CI = 0.0113, 0.0179), while self-efficacy significantly moderated the specific linking between OHL on OHBs (β = 0.0003, Boot CI = 0.0000, 0.0005). Ultimately, this theoretical model accounted for 38.2% of the total variance in oral health behaviors.

Conclusion: The notably high prevalence of inadequate OHL and risk factors identified in this study suggests a need for comprehensive attention from governments, local authorities, healthcare professionals, and communities. The Vietnamese Health Literacy in Dentistry-14 version provides a valid and reliable measurement to quickly and comprehensively assess the oral health literacy of Vietnamese senior citizens. Social support should be tailored to meet the individual needs of older adults, empowering them. Enhancing oral health literacy and self-efficacy may be effective strategies for improving oral health behaviors in this population.