Development of a Clinical Prediction Rule for Venous Thromboembolism in Patients with Acute Leukemia
Fatimah Al‐Ani, Yimin Pearl Wang, Alejandro Lazo‐Langner
Abstract
Abstract Risk factors for venous thromboembolism in patients with solid tumors are well studied; however, studies in patients with acute leukemia are lacking. We conducted a retrospective cohort study of adult patients diagnosed with acute myeloid leukemia and acute lymphoblastic leukemia diagnosed between June 2006 and June 2017 at a tertiary care center in Canada. Potential predictors of venous thromboembolism were evaluated using logistic regression and a risk score was derived based on weighed variables and compared using survival analysis. Internal validation was conducted using nonparametric bootstrapping. A total of 501 leukemia patients (427 myeloid and 74 lymphoblastic) were included. Venous thromboembolism occurred in 77(15.3%) patients with 71 events occurring in the first year. A prediction score was derived and validated and it included: previous history of venous thromboembolism (3 points), lymphoblastic leukemia (2 points), and platelet count > 50 × 109/L at the time of diagnosis (1 point). The overall cumulative incidence of venous thromboembolism was 44% in the high-risk group (≥ 3 points) versus 10.5% in the low-risk group (0–2 points) and it was consistent at different follow-up periods (log-rank p < 0.001). We derived and internally validated a predictive score of venous thromboembolism risk in acute leukemia patients.