Title: Incidence and risk factors of postoperative delirium after peripheral vascular surgeryrnResponsesrn Name: Minyoung Kim, APN, PhD1 rn Euna Park, RN, PhD2rn1 APN, PhD, Assistant Professor, Department of Nursing, Ulsan University, Ulsan, South Korea rn 2 RN, PhD, Associate Professor, Department of Nursing, Pukyong University, Busan, South KorearnPurpose: Postoperative delirium has increased recently along with the aging population. Vascular surgery has been reported to be associated with a high incidence of postoperative delirium. We evaluated the incidence and the risk factors of postoperative delirium after vascular surgery. rnrnMethods: 212 patients who underwent vascular surgery in hospital during 3 years were retrospectively analyzed. Incidence, onset, duration, and risk factors were analyzed. rnrnResults: Mean age was 67.2 (SD ± 10.4) and male were 84.0%. Postoperative delirium was developed in 56 patients (26.4%) mostly on the day of operation and postoperative day one (range 0-3). Mean duration of delirium was 2.2 days (1-7). Logistic regression analysis identified the following risk factors; old age (OR; 1.107, 95% CI; 1.043 to 1.174; P=.001), hearing impairment (OR; 14.915, 95% CI; 1.350 to 12.615; P=.027), low physical activity (OR; 3.294, 95% CI; 1.129 to 9.609; P=.029), pain score (OR; 1.629, 95% CI; 1.095 to 2.423; P=.016), low serum albumin (< 3.2 g/dL) (OR; 3.409, CI; 1.206 to 9.634; P=.021), low serum cholesterol (< 120 mg/dL) (OR; 3.118, CI; 1.202 to 8.086; P=.019). rnrnConclusion: The incidence of delirium presents in more than a fourth of all vascular surgery cases. The vulnerable population with delirium can be identified pre- or immediate post-operatively based on the study result.rn