Risk factor model to predict venous thromboembolism in hospitalized medical patients.
J Hosp Med. 2011 Apr;6(4):134-141
Authors: Rothberg MB, Lindenauer PK, Lahti M, Pekow PS, Selker HP
BACKGROUND: The Joint Commission requires that all medical inpatients be assessed for venous thromboembolism (VTE) risk, but available risk stratification tools have never been validated. METHODS: We conducted a retrospective cohort study of patients age ?18 years, admitted to 374 US hospitals in 2004-2005, with a primary diagnosis of pneumonia, heart failure, chronic obstructive pulmonary disease (COPD), stroke, and urinary tract infection, and length of stay ?3 days. Subjects were randomly assigned (80/20) to a derivation or validation set. We then assessed VTE (International Classification of Diseases, Ninth Revision [ICD-9] code plus diagnostic test plus treatment), patient demographics, 21 potential risk factors, and other comorbidities. We created a VTE risk stratification tool using multivariable regression modeling and applied it to the validation sample. RESULTS: Of 242,738 patients, 612 (0.25%) patients fulfilled our criteria for VTE during hospitalization, and an additional 440 (0.18%) were readmitted for VTE within 30 days (overall incidence of 0.43%). In the multivariable model, age, sex, and 10 additional risk factors were associated with VTE. The strongest risk factors were inherited thrombophilia (OR 4.00), length of stay ?6 days (OR 3.22), inflammatory bowel disease (OR 3.11), central venous catheter (OR 1.87), and cancer. In the validation set, the model had a c-statistic of 0.75 (95% CI 0.71, 0.78). Deciles of predicted risk ranged from 0.11% to 1.46% with observed risk over the same deciles from 0.17% to 1.81%. CONCLUSIONS: The risk of symptomatic VTE in general medical patients is low. A risk factor model can identify those at sufficient risk to warrant pharmacologic prophylaxis. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine.
PMID: 21480491 [PubMed - as supplied by publisher]