Abstract P193: Infection Type and Severity are Risk Factors for Hospital-Acquired Venous Thromboembolism in Medical Inpatients

Abstract

Introduction: Hospital-acquired venous thromboembolism (HAVTE) leads to increased length of stay, cost, morbidity, and is a target of government quality measures. How infection relates to HAVTE risk is unknown. We wished to identify infection-related risk factors for HAVTE to help identify at-risk patients and to guide prevention efforts. Hypothesis: We hypothesized that increased infection severity, affected organ system, and positive microbiology culture results were associated with HAVTE in medical inpatients. Methods: HAVTE between 2009-2012 were identified by ICD-9 codes with confirmatory imaging at a 500 bed teaching hospital. ICD-9 codes, microbiology results, lab and vital sign data, and medication records were used to classify infections as presented in the Table. Logistic regression was used to determine odds ratios (OR) and 95% confidence intervals (CI) for HAVTE adjusting for known HAVTE risk factors in the MITH score, a previously developed HAVTE risk score for medical inpatients. Models incorporated known HAVTE risk factors and assessed each variable from the Table individually. Results: In 20,327 medical admissions there were 113 hospital-acquired HAVTE (incidence: 0.56%). The table presents the association between infection-related risk factors and HAVTE. Septic shock (OR 7.48), sepsis (OR 5.9), and MSSA culture isolate (OR 6.39) had the greatest point-estimates of HAVTE after adjusting for known HAVTE risk factors. Conclusions: Infection severity, affected organ system, and microbiologic etiology were risk factors for HAVTE after adjusting for known risk factors. The relationship between these risk factors and thrombosis is likely complex, but these risk factors are easily measureable using the electronic health record. These results may help facilitate HAVTE prevention by further identifying high risk patients.