Abstract
BACKGROUND: The aging population, including octogenarians (aged 80-89) and nonagenarians (aged 90-99), is rapidly increasing. Understanding their self-rated health in urban and rural settings is vital for public health policy development. This study examined factors associated with self-rated health among octogenarians and nonagenarians across urban and rural areas of South Korea. METHODS: We analyzed data from 21,896 older adults (aged 80-99) from the 2023 Korea Community Health Survey. Self-rated health was assessed on a 5-point scale and categorized as "good" or "poor." Variables included age, residence area (urban/rural), sociodemographic characteristics, health behaviors, healthcare utilization, morbidity, and social interactions. Descriptive statistics were used to examine variable distributions, and logistic regression models identified factors associated with self-rated health in each age group and residential area. RESULTS: Among octogenarians, 18.7% in urban areas reported good self-rated health, compared to 15.0% in rural areas. Conversely, a smaller proportion of nonagenarians in urban areas (13.6%) reported good self-rated health than those in rural areas (14.7%). Among octogenarians, having a high school education or higher was associated with better self-rated health compared to those with no formal education (urban OR = 1.67, 95% CI = 1.39-2.00; rural OR = 1.67, 95% CI = 1.30-2.14). Furthermore, a monthly household income of 3 million Korean Won (KRW) or more, compared to an income of less than 1 million KRW, was associated with better self-rated health among octogenarians (urban OR = 1.35, 95% CI = 1.09-1.66; rural OR = 1.54, 95% CI = 1.19-2.00). The associations between educational level and self-rated health were less pronounced among nonagenarians. Consistently across both age groups and settings, regular walking (OR range: 1.39 [95% CI = 1.21-1.60] for rural octogenarians to 2.17 [95% CI = 1.78-2.64] for urban nonagenarians), good self-rated oral health (OR range: 2.51 [95% CI = 1.96-3.22] for urban nonagenarians to 3.51 [95% CI = 3.01-4.09] for rural octogenarians), and participation in social activities (OR range: 1.23 [95% CI = 1.09-1.41] for urban octogenarians to 1.58 [95% CI = 1.20-2.07] for rural octogenarians) were positively associated with good self-rated health. CONCLUSIONS: Characteristics associated with self-rated health differed significantly between octogenarians and nonagenarians in rural and urban areas. Public health strategies must support health-promoting behaviors such as regular walking, enhance oral health services, improve healthcare accessibility, reduce environmental stressors, and strengthen social support networks to promote health among octogenarians and nonagenarians.