Trends of Lower Limb Amputation Rates Over Twelve Years in Oklahoma

Introduction: Vulnerable and underrepresented groups at risk for limb loss are common in Oklahoma — including one of the highest proportions of American Indians and uninsured of any state. This study is the first to examine contemporary non-traumatic amputation trends in Oklahoma. Methods: We conducted a 12-consecutive-year observational study using Oklahoma’s hospital discharge data from 2008-2019. Discharges among patients over 19 years of age with a primary or secondary diagnosis of diabetes and/or peripheral arterial disease (PAD) were included. Diagnoses and amputation procedures were identified using ICD-9 and ICD-10 codes. Amputation rates were calculated per 1,000 discharges. Trends in amputation rates were measured by annual percentage changes (APC) using Joinpoint. Differences in amputation rates across demographic groups were evaluated by prevalence ratios using SAS. Results: Over 5,000,000 discharges were identified—24% included a diabetes and/or PAD diagnosis. The overall amputation rate was 12 among discharges with diabetes and/or PAD and increased from 8.6 to 16.2 (APC: 6.0, 95% CI:4.7-7.3). Minor amputations represented 60% of all amputations and increased more rapidly (APC: 8.1, 95% CI:6.7-9.6) than major amputations (APC: 3.1, 95% CI:1.5-4.7). Amputation rates were the highest in the 45-49 years age group (18.8), males (16.7), American Indians (19.2), uninsured (21.2), and non-married patients (12.7). These disparities were associated with significant prevalence ratios (p = 0.001). Conclusion: The amputation rate in Oklahoma has nearly doubled in 12 years with minor amputations increasing at a more rapid rate. Risk factors unique to Oklahoma will help frame a statewide limb salvage program.