The Association Between Urbanization and Frailty Status in China

Background: A frailty index (FI) can identify individuals with frailty in a population of interest. Previous literature suggests a need for frailty assessment methods for older adults in China and that urbanization may impact frailty status. We used a FI to examine the association between frailty and urbanization as living in a less urbanized area may put older adults at a higher risk frailty and poor healthcare outcomes. Methods: We included adults aged 55 years and older (n = 7695) from the China Health and Nutrition Survey (2018). The FI was based on health outcomes correlating with a deficit score divided by number of health items: robust (<0.08), pre-frail (0.08-0.24), and frail (≥0.25). We used multinomial logistic regression models to examine associations between urbanization tertile (low, medium, and high) and frailty, using our novel FI. We also conducted sub-analyses examining how urbanization level modifies the relationship between frailty status and region of residence, and education and income levels. Results: Living in an area of low versus high urbanization was associated with higher odds of frail versus robust (1.5; 1.2-2.0), and pre-frail versus robust (1.6; 1.4-2.0) status in the fully adjusted model. Generally, higher odds of worse frailty status (e.g., pre-frail or frail) was associated with lower tertiles of urbanization for region, income, and education when compared to the highest urbanization tertile. Conclusions: A FI can help identify specific characteristics that may benefit from individualized interventions to counteract frailty. Living in less urbanized areas was associated with higher odds of pre-frailty and frailty. Inclusion of urbanization level, geographic residence, and social determinants of health in FI development can help identify older adults most at risk of frailty and contribute to individual and policy-level frailty prevention interventions.