Association between health literacy and self-rated health indicators in people with and without type 2 diabetes: A population-based study of 7485 Danes

AIMS: We aimed to 1) assess the prevalence of low health literacy (HL) in people with and without T2D, 2) estimate the impact of HL on self-rated health, depression risk, and self-rated oral health, and 3) determine if these associations differ between people with and without type 2 diabetes (T2D). METHODS: We used data from the Health in Central Denmark survey 2022 among 7485 adults (3250 with T2D and 4235 without). Self-reported answers to four HL scales ('Information', 'Management', 'Engagement', 'Navigation') from the Health Literacy Questionnaire (HLQ), self-rated health (SF-12), depression risk (WHO-5), and self-rated oral health were assessed. Multivariable logistic regression (odds ratios (OR) with 95% confidence intervals (CI)) was used to adjust for confounders stratified by diabetes status. Effect modification by diabetes status was tested. RESULTS: Low HL ranged from 5.3% to 28.8% in people with T2D and 2.9-19.7% in those without, depending on the HL scale. Each one-unit increase in HL significantly reduced the odds of poor health outcomes in both groups. The strongest associations were between 'Information' and poor self-rated health (OR=0.28 (CI: 0.23;0.33) for people with diabetes and OR= 0.34 (CI: 0.28;0.40) for people without diabetes) and the weakest associations were between 'Navigation' and poor oral health (OR=0.68 (CI: 0.61;0.75) for people with diabetes and OR= 0.58 (CI: 0.52;0.65) for people without diabetes). No significant differences between groups were found, except for the association between two HL scales ('Management' (p-value=0.015) and 'Engagement' (p-value=0.004)) and oral health. CONCLUSIONS: Low HL was associated with poor health outcomes in both individuals with and without T2D. Improving HL, especially in healthcare navigation, could be essential for better health outcomes in both groups.