OC 32.4 - Predictors of Venous Thromboembolism Chemoprophylaxis in Hospitalized Medical Patients: The Medical Inpatients Thrombosis and Hemostasis (MITH) Study

Monday, June 26, 2023

11:30 – 11:45 ET

Room: 710A

Session Available As: On-Demand

Presenting Author(s)

Allen B. Repp, MD, MSc (he/him/his)

Professor
Department of Medicine, The Larner College of Medicine at the University of Vermont
Burlington, Vermont, United States

Co-Author(s)

Andrew D. Sparks, MS

Statistician
The Larner College of Medicine at the University of Vermont
Burlington, Vermont, United States
KW

Katherine S. Wilkinson, MS

Statistician
The Larner College of Medicine at the University of Vermont
Burlington, Vermont, United States
NR

Nicholas S. Roetker

Epidemiologist
Hennepin Healthcare Research Institute
Minneapolis, Minnesota, United States
Jordan K. Schaefer, MD

Clinical Professor
Department of Internal Medicine, Division of Hematology/Oncology, University of Michigan Health
Ann Arbor, Michigan, United States
Ang Li, MD, MS

Assistant Professor
Section of Hematology-Oncology, Baylor College of Medicine
Houston, Texas, United States
LM

Leslie A. McClure

Professor and Chair
Department of Epidemiology and Biostatistics, Dornsife School of Public Health, Drexel University
Philadelphia, Pennsylvania, United States
DT

Deirdra R. Terrell

Associate Professor
Department of Biostatistics & Epidemiology, Hudson College of Public Health
Oklahoma City, Oklahoma, United States
AF

Augusto Ferraris

MPH Candidate
University of Washington School of Public Health
Seattle, Washington, United States
AA

Alys Adamski

Epidemiologist
Division of Blood Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention
Atlanta, Georgia, United States
NS

Nicholas L. Smith

Professor
Department of Epidemiology, University of Washington
Seattle, Washington, United States
Neil A. Zakai, MD, MSc (he/him/his)

Professor
Hematology/Oncology Division, Department of Medicine, The Larner College of Medicine at the University of Vermont
Burlington, Vermont, United States

Background: Despite guidelines recommending risk stratification for hospital-acquired venous thromboembolism (HA-VTE) to guide prophylaxis decisions, numerous studies demonstrate both under-utilization and over-utilization of VTE chemoprophylaxis in hospitalized patients and the predictors of chemoprophylaxis initiation in medical inpatients remain largely unknown.

Aims: To determine the predictors of VTE chemoprophylaxis initiation in adults hospitalized on medicine services.

Methods: We performed a cross-sectional analysis using electronic medical record data from adults hospitalized 2018-2019 on medical services at four academic medical centers (Harris Health, Hennepin Healthcare, University of Michigan, University of Vermont). Patients admitted with VTE, admitted to the ICU, or who received intermediate or therapeutic-level anticoagulation on hospital day 1 or 2 were excluded. We used age-, sex-, race/ethnicity-, and site-adjusted logistic regression to determine predictors of VTE chemoprophylaxis initiation, defined as administration of chemoprophylaxis on the day of or the day after admission. Predictors were admission vital signs, laboratory studies, conditions known at admission, and Elixhauser Comorbidity measures.

Results: Among the included 107,096 hospitalized patients, 48,881 (45.6%) received and 58,215 (54.4%) did not receive VTE chemoprophylaxis (Table 1). Chemoprophylaxis rates varied significantly among hospitals (Table 2). Older age, female sex, and Black race were associated with higher probability of chemoprophylaxis. After adjustment, the strongest predictors of increased VTE chemoprophylaxis included lymphoma, solid tumor, neurologic disorders, and chronic pulmonary disease. Thrombocytopenia, bleeding diagnoses, coagulopathy, atrial fibrillation, and absence of insurance were associated with decreased odds of VTE chemoprophylaxis (Table 2).

Conclusion(s): Initiation of VTE chemoprophylaxis was inconsistently associated with established risk factors for HA-VTE and was less likely in people with bleeding or risk factors for bleeding. Sex, race, and insurance status were associated with VTE chemoprophylaxis, but those analyses were not yet adjusted for HA-VTE risk factors other than age. Implementation of validated VTE risk models could help optimize VTE chemoprophylaxis administration.

Learning Objectives:

Articulate factors associated with venous thromboembolism (VTE) chemoprophylaxis in hospitalized medical patients.
Compare observed predictors of VTE chemoprophylaxis in hospitalized medical patients with validated predictors of VTE risk.
Explore the relationship between VTE chemoprophylaxis administration and overall predicted VTE risk.