Statistical Analysis
SECONDARY
The historical rate of HA-VTE at our institution was 10 per 1000 patients. With at least 15 000 patients randomized 1:1 to the intervention and control groups (ie, 7500 per group), a 2-sample Fisher exact test achieves 80% power to detect an absolute risk reduction from 10 per 1000 in the control group to 5.95 per 1000 in the intervention group with a type I error rate of 5%.Primary analyses compared the intervention and control groups and were conducted by modified intention to treat, with the modification that randomized patients who already initiated thromboprophylaxis on the first day of their hospitalization were excluded. Secondary as-treated analyses were also conducted, considering whether treatment recommendations were followed by the primary clinical team. As-treated analyses were limited to the strata of patients with elevated risk of developing HA-VTE (predicted probability ≥2.5%), with comparisons between patients randomized to the control group, randomized to the intervention but treatment recommendations were not followed, and randomized to the intervention and treatment recommendations were followed.Sociodemographic characteristics (including race and ethnicity as reported by patients and recorded in the EMR) and baseline clinical characteristics were summarized using standard descriptive statistics. Race and ethnicity were included to ensure the model performed consistently across all groups. The proportion of patients diagnosed with HA-VTE (primary outcome) and the proportion of patients who received prophylactic anticoagulation (secondary outcome) were compared between the intervention and control groups using unadjusted risk differences with 95% CIs. We did not specify a priori any adjustment variables to include in multivariable models, and no variable exhibited a clinically meaningful imbalance between the intervention and control groups. For the primary outcome, a 2-sided 