Health Literacy and Time-Specific Toothbrushing Practices in Older Adults: An Analysis of the Korean National Health and Nutrition Examination Survey, KNHANES IX (2023).

Abstract

Background: Evidence remains limited on whether health literacy is associated with time-specific toothbrushing occasions across the day.

Objective: To examine time-specific toothbrushing patterns according to health literacy levels and to determine whether lower health literacy was associated with failure to brush at key times among older adults in Korea.

Methods: Using the KNHANES IX (2023), we analysed 1,836 adults aged ≥ 65 years. Toothbrushing on the previous day was reported for eight occasions (before breakfast, after breakfast, before lunch, after lunch, before dinner, after dinner, after having a snack, and before bedtime). Health literacy (10-item scale; 10-40) was categorised as low (≤ 28), moderate (29-30), or high (≥ 31). Complex-sample weighted logistic regression estimated ORs (95% CIs) for failure to brush at specific times with hierarchical adjustment (demographic characteristics, socioeconomic status, health practices).

Results: Lower health literacy was more common among older adults and those with lower income/education. Brushing was most frequent after breakfast and after dinner. Compared with high health literacy, low health literacy was associated with higher odds of not brushing before breakfast (OR 1.43, 95% CI 1.02-2.00) and after lunch (OR 1.38, 95% CI 1.00-1.91) after adjustment for sociodemographic factors; associations were attenuated after full adjustment. No consistent associations were found for failure to brush after breakfast or before bedtime.

Conclusions: Health literacy was associated with time-specific toothbrushing, with before-breakfast and after-lunch brushing identified as priority prevention targets among older adults.