Incidence of hospital-acquired venous thromboembolic disease

There is limited knowledge of the incidence of venous thromboembolic disease (VTE) during hospitalization, since most of these are community-based data.

To estimate the incidence rate (IR) of VTE developed during hospitalization.

Prospective cohort of all inpatients admitted in a university tertiary hospital, in Argentina. The inclusion criteria were defined as: adult patients consecutively admitted from July/2006 to August/2013, for any cause. Patients admitted for VTE were excluded; all patients at the time of admission were free of event. Each person was followed contributing time at risk, from admission to event, discharge or death. VTE incident cases were captured from the Institutional Registry of Thromboembolic Disease (ClinicalTrials.gov Identifier NCT01372514). Incidence rate was calculated with 95% confidence intervals.

The crude incidence rate of VTE for clinical patients was 0.49 (95%CI 0.45-0.55) per 1,000 cases person-days, and IR adjusted for WHO was 0.23 (95%CI 0.19-0.26). The crude IR of VTE for surgical patients was 0.25 (95%CI 0.23-0.27), and IR adjusted for WHO was 0.13 (95%CI 0.10-0.17). The incidence rate ratio (IRR) for VTE shows that surgical admission reduces the IRR and age categories increases the thrombosis rate risk, after adjustment for age category, sex and surgical admission.

This study suggests that there is a high risk of VTE in hospitalized patients and is still a frequent problem.