Impact of Socioeconomic Status on Major Amputation in Patients with Peripheral Vascular Disease and Diabetes Mellitus.

BACKGROUND

Both peripheral vascular disease (PVD) and diabetes mellitus (DM) are leading causes of lower extremity amputation. The Area Deprivation Index (ADI) is a tool used to estimate socioeconomic status (SES) based off a person's 9-digit zip code, and this value has been shown to correlate with poor health outcomes. We sought to understand the effect of SES on major amputation in diabetic patients with PVD in a single healthcare system.

METHODS

All patients presenting to a single healthcare system with dual diagnosis of PVD and DM from January 2012 to December 2017 were identified using International Classification of Diseases (ICD) 9/10 codes. Patients undergoing major amputation (below-knee and above-knee) were identified by Current Procedural Terminology (CPT) codes and compared to those who did not have amputation. The ADI score and comorbid disease processes were identified. The Mann-Whitney U-test was performed to compare ADI scores between the amputation and nonamputation groups. Categorical variables were analyzed using the Chi-squared or Fisher's exact test, and t-tests were used for continuous variables. A logistic regression was performed to test the association between SES and amputation status.

RESULTS

A total of 2,009 patients were identified, of which 85 underwent major amputation. After adjusting for comorbidities, patients in the amputation group had higher ADI scores as compared to those who did not have amputation (median ADI score 8 vs. 6, P < 0.05). Logistic regression modeling demonstrated an Odds Ratio of 1.10 (95% confidence interval: 1.01-1.19), indicating the odds of being in the amputation group are increased by 10% for every 1-point increase in the ADI score.

CONCLUSIONS

After controlling for comorbidities, patients with PVD and DM residing in neighborhoods with lower SES have increased odds of undergoing major lower-limb amputation than those from neighborhoods with higher SES despite receiving care at the same healthcare system. Further study is warranted to determine factors contributing to this difference.