Prevalence and risk factors of hospital acquired venous thromboembolism.

Objectives: To investigate the prevalence, clinical characteristics and risk factors of hospital acquired venous thromboembolism (HA-VTE) in a Chinese Hospital.

Methods: Retrospective analysis of patients diagnosed as HA-VTE in a single institution from January 2016 to December 2022 was performed. Patients with VTE prior to admission or within 48 h after admission were excluded. Demographic data of patients was retrieved from the electronic medical database, and parameters affecting the occurrence of HA-VTE were analyzed.

Results: 4,022 patients from 321,997 episodes of medical admissions were diagnosed as VTE. Among these, 952 (23.7%) fulfilled the criteria of HA-VTE, corresponding to an incidence of 0.296%. 76% of patients presented with HA-deep vein thrombosis (DVT) alone, 13% presented with isolated HA-pulmonary embolism (PE), and 11% presented with concomitant HA- DVT and PE. Risk factor analyses showed statistically higher incidence in patients with elder age (67.5 ± 15.5 vs 48.3 ± 17.2 years, p < .001), male gender (0.346% vs 0.262%, p < .001), malignancy (0.513% vs 0.252%, p < .001), trauma (0.659% vs 0.28%, p < .001), emergency admission (0.664% vs 0.186%, p < .001), ICU stay (2.981% vs 0.226%, p < .001), and patients undergoing major surgery (0.702% vs 0.176%, p < .001). Patients with HA-VTE had longer hospital stay (22.5 ± 26.6 vs 7.21 ± 9.23 days, p < .001) and higher mortality rate (8.51% vs 1.01%, p < .001). The crude incidence rate of HA-VTE increased annually from 0.75 per 1,000 patients in 2016 to 5.89 per 1,000 patients in 2022. The subspecialties with the highest incidence rate of HA-VTE were cardiovascular surgery (1.40%), neurosurgery (1.10%), and respiratory medicine (0.72%).

Conclusion: This is one of the few large scale studies to show that HA-VTE, accounting for nearly one quarter of all VTE events, occurs in 0.296% of adult hospitalizations. Patients with elder age, malignancy, ICU stay, and undergoing major surgery require more intensive HA-VTE surveillance and prevention.