A Snapshot of Venous Thromboembolism (VTE): Retrospective Audit of Events at a Metropolitan Tertiary Referral Hospital

Background

Facility-level review of hospital-acquired venous thromboembolism (HA-VTE) cases, including pulmonary embolism (PE) and deep vein thrombosis (DVT), can provide insight into the local drivers of this preventable complication.

Aim

To determine the nature of HA-VTE, patient characteristics, VTE risk assessment completion and appropriateness of prescribed VTE prophylaxis at a metropolitan tertiary referral hospital and to compare the number of HA-VTE detected by audit of imaging scans with those reported by clinical coding.

Methods

We conducted a retrospective electronic medical record audit encompassing all patients diagnosed with HA-VTE via ventilation-perfusion scan, computed tomographic pulmonary angiography and/or doppler ultrasound using a demographic and VTE risk assessment audit tool during selected months of 2017-2019. We compared the number of manually audited cases with the number of performance unit-coded cases for the same months.

Results

The months of May 2017, October 2017, April to July 2018 and April to July 2019 were included. There was a significant difference between HA-VTE detected via manual audit (147 events) and hospital coding (18 events), p=0.002. Manual audit patients were majority non-surgical (65%), female (58%), over 60 years (80%), at moderate VTE risk (71%) with reduced mobility (52%). There were 108 DVT-only (73%), 23 PE-only (16%) and 16 DVT plus PE events (11%). Notable risk factors were moderate to major surgery (30%), active malignancy or cancer treatment (24%) and active infection (27%). Most patients were prescribed appropriate VTE prophylaxis (74%) and had documented VTE risk assessment (68%). Appropriate VTE prophylaxis was significantly associated with using an electronic clinical decision support tool during VTE risk assessment (p=0.024).

Conclusion

Facility-driven HA-VTE audits provide opportunity to developed targeted initiatives for at-risk patients at a local level. Greater numbers of HA-VTE identified via manual audit suggest the need for future real-time documentation of HA-VTE to assist with efficient case review.