Footing the Bill: Income Inequality and Disparities in Diabetic Limb Preservation in a Nationwide Population-Based Study

Abstract Background Income inequality has a profound impact on health outcomes by limiting access to preventive care, early diagnosis, and effective treatment with chronic conditions such as diabetes. Our aim was to investigate the impact of income inequality on diabetic foot amputation rates, focusing on disparities in outcomes among income levels. Methods This retrospective cohort study used data from the Korean National Health Insurance Service database that tracked 2,580,585 diabetic patients from 2009 to 2019. Participants were categorized into income quartiles (Q1–Q4) with Q1 being the lowest-income group. The primary outcome was the first occurrence of diabetes-related lower extremity amputation (LEA). Results LEA performance rates were inversely related to income, with Q1 having the highest rate (0.64 per 1,000 person-years) and Q4 the lowest (0.45 per 1,000 person-years). Adjusted models revealed a protective effect of higher income on LEA. The difference appeared to be more pronounced in individuals younger than 65 years, based on stratified analysis. Conclusion Income inequality is strongly associated with disparities in diabetic foot outcomes, with higher income linked to improved limb preservation, especially among younger individuals. These findings underscore the importance of targeted interventions to mitigate structural inequities, reduce the socioeconomic burden of diabetes, and enhance quality of life in vulnerable populations.