M. Reilly1,2, I.C. Cohen3, S.L. Watson3, S. Minc4, K.J. Ho1, J.M. Feinglass5 5Northwestern University, Division Of General Internal Medicine, Chicago, IL, USA 1Northwestern University, Division Of Vascular Surgery, Department Of Surgery, Chicago, IL, USA 2Northwestern University, Northwestern Quality Improvement, Research, And Education In Surgery (NQUIRES), Chicago, IL, USA 3Northwestern University, Feinberg School Of Medicine, Chicago, IL, USA 4Duke University, Division Of Vascular And Endovascular Surgery, Durham, NC, USA
Introduction:
Lower extremity (LE) amputation is a devastating consequence of peripheral artery disease (PAD) and diabetes mellitus (DM). While preventive measures and care have improved over time, the prevalences of DM and PAD are increasing. The trajectory of population based LE amputation rates has not been fully explored. This study aimed to analyze changes in LE amputation rates for adult Illinois residents over an eight-year period across multiple sociodemographic populations.
Methods:
Hospital records for LE amputations at the above knee (AK), below knee (BK), and through foot (TF) level from 2016 to 2023 were identified from the Illinois Hospital Association COMPdata database. To identify amputations secondary to PAD and DM, adults 34 years or younger, International Classification of Diseases 10 codes for oncologic or trauma-related amputation, non-Illinois residents, and isolated toe amputations were excluded. Patient zip codes were matched to census Zip Code Tract Area (ZCTA) to identify percent of families living at or below the federal poverty level. Population denominators for Illinois residents aged 35 years or older and for specific age, sex and race/ethnicity populations were calculated using American Community Survey 2022 five-year estimates. Year-specific and overall amputation rates per 100,000 were calculated by age, sex, race/ethnicity and ZCTA poverty level. Monthly amputation frequencies were used to plot trends over the 90-month study period. One sample chi squared tests were used to test the significance of differences in rates per 100,000 between 2016 to 2023.
Results:
There were 30,903 amputations (71.2% male, 25.0% non-Hispanic Black residents, and 12.0% living in zip codes with 20% or more residents below the federal poverty level) from 193 non-federal Illinois hospitals, 20.2% AK, 34.8% BK, and 45.0% TF amputations (Figure). There was a 67.5% increase in all amputations from 2016 to 2023, with a significant increase in the months following the COVID-19 outbreak in March 2020. Males aged 65-74 had the greatest increase in amputations from 90.1 to 171 per 100,000. Non-Hispanic Black residents experienced increases from 77.0 to 124.5 per 100,000 compared to increases from 33.2 to 51.1 per 100,000 for non-Hispanic White residents. Amputation rates increased as ZCTA poverty level increased, with the highest poverty level experiencing an increase from 83.0 to 130.6 amputations per 100,000.
Conclusion:
Compared to a 2008 evaluation of non-traumatic LE amputation rates in Illinois, there have been dramatic increases. Future efforts should focus on addressing sources of disparities in PAD and diabetes care in populations at high risk for amputation, like older males and non-Hispanic Black residents.