Venous Thromboembolism Rates in Transferred Patients: A Cross-Sectional Study

Abstract

Background: Patients undergoing a transfer during a hospitalization may be more likely to be diagnosed with a venous thromboembolism (VTE) than patients who are not transferred. Objective: To determine whether transferred patients have an increased prevalence of VTE diagnosis. Design: This was a cross-sectional study comparing VTE diagnosis rates between transferred patients and non-transferred patients. For the years 2012–2014, the University HealthSystem Consortium database of multiple community and academic medical centers throughout the United States was parsed using ICD-9 VTE diagnosis codes and patient’s point of origin. Patients: Patients were included in the analysis as transferred patients if their point of origin was a skilled nursing facility, another acute care facility or another facility. Non-transferred patients were those whose point of origin was a clinic or those with a non-facility point of origin. Main Measures: The primary comparison of VTE prevalence during hospitalization between transferred and non-transferred patients in the years 2012–2014. Subgroup analysis looked at level I trauma status and case mix index (CMI) to determine whether these had an effect on VTE prevalence. Key Results: From 2012 to 2014, a total of 225 unique hospitals and 12,036,029 patients were analyzed, and the prevalence of VTE in transferred patients and non-transferred patients was 3.43% and 1.91% (RR 1.80; 95% CI 1.78–1.81; P <0.001), respectively. VTE prevalence in transferred versus non-transferred patients at level I trauma centers was 3.42% versus 1.88% (RR = 1.82; 95% CI 1.80–1.85; P <0.001). The 3-year average CMI of transferred versus non-transferred patients was 3.53 versus 2.26 (P < 0.001). Conclusions: Transferred patients have a higher prevalence of VTE than non-transferred patients, regardless of level I trauma designation. Higher VTE rates in transferred versus non-transferred patients was minimally correlated with CMI.