Systemic vasculitis is associated with a higher risk of lower extremity amputation in patients with severe peripheral arterial occlusive disease: a secondary analysis of a nationwide, population-based health claims database.

Previous research has shown that diabetes mellitus increases the risk of lower extremity amputation in patients with peripheral arterial occlusive disease. However, to our knowledge, no studies have investigated whether systemic autoimmune disease, in particular systemic vasculitis is associated with a higher risk of lower extremity amputation in these patients. To investigate the association between systemic autoimmune disease and lower extremity amputation in patients with severe peripheral arterial occlusive disease based on a secondary analysis of a nationwide, population-based health claims database. Using the inpatient datafile of the Taiwan's National Health Insurance Research Database (NHIRD), we identified 432 patients with severe peripheral arterial occlusive disease that required hospitalization between 2000 and 2012. We also identified patients who had undergone lower extremity amputation and their comorbidities using the same datafile. The risk of lower extremity amputation was assessed using multiple logistic regression analysis, adjusting for age, sex, insured amount, the urbanization level of residence, and the presence of comorbidities. Among patients with severe peripheral arterial occlusive disease, those with systemic vasculitis exhibited a significant higher risk of lower extremity amputation (adjusted odds ratio [aOR] = 6.82, p < 0.001). Diabetes mellitus (aOR = 4.90, p < 0.001) and chronic obstructive pulmonary disease (aOR = 2.87, p = 0.007) were also significantly associated with a higher risk of lower extremity amputation. Among patients with severe peripheral arterial occlusive disease, a significantly higher risk of lower extremity amputation was observed in those with systemic vasculitis.