Patterns of multimorbidity and their association with complete tooth loss: The moderating role of health literacy in the Lifelines Cohort

Multimorbidity may affect oral health, especially in individuals with limited health literacy (HL), or specific multimorbidity patterns; however, evidence remains scarce. Understanding these associations could improve early detection and prevention, both in clinical care and public health strategies. This study aimed to assess the association of multimorbidity and multimorbidity patterns with complete tooth loss, i.e. edentulism, and whether HL moderates this association. A total of 42 357 participants from the prospective multigenerational Dutch Lifelines Cohort Study were included. Multimorbidity was defined by ≥2 affected disease domains. Multimorbidity patterns were constructed with latent class analysis. Associations between multimorbidity (and patterns) with edentulism were assessed using logistic regression, with HL as a potential moderator. Models were adjusted for age, household income, and education. Edentulism prevalence was 9.5% and was higher among limited than adequate HL (14.5% vs. 7.9%) and among multimorbid vs. absent (19.5% vs. 7.7%). We identified five patterns: (1) Endocrinological + Psychiatry; (2) Cardiovascular + Endocrinological; (3) Neurological + Otorhinolaryngologic; (4) Endocrinological + Otorhinolaryngologic, and (5) Otorhinolaryngologic + Psychiatric. The odds of edentulism were 2.26 higher (95% CI: 2.06-2.47) in multimorbid. Pattern 2 (Cardiovascular + Endocrinological) had the highest odds ratio of edentulism (OR: 3.52, 95% CI: 3.03; 4.08) compared to multimorbidity absent. HL did not moderate the associations between multimorbidity and edentulism. Edentulism is more likely in the case of multimorbidity, especially if cardiovascular and endocrinological conditions co-occur, an explanation being the shared risk factors. This association remains the same across different HL levels. Our findings support collaborative medical and oral healthcare.