Purpose
Duplex Compression Ultrasound is the primary imaging modality for emergent assessment of suspected lower limb Deep Vein Thrombosis (DVT). As per the current Australian Choosing Wisely recommendation, ultrasound is indicated in ambulatory patients if the Wells’ DVT Score is either > 2 or < 2 with an elevated D-dimer. [1]
The purpose of this audit was to assess the appropriateness of ultrasound in patients with suspected lower limb DVT at Townsville University Hospital Emergency Department (TUH-ED) and whether this constitue Low Value care.
Low Value...
Methods and materials
This was a retrospective audit of consecutive ambulatory patients presenting to TUH-ED between October 2020 and January 2021 with a suspected lower limb DVT. The appropriateness of ultrasound was benchmarked against the current Australian Choosing Wisely recommendation.
The following data variables were collected from each patient's medical record.
- Was the patient ambulatory? Yes - continue, No - stop data collection and exclude patient
- Was Well’s DVT score documented ?
- If Well's DVT score is documented, what was the value ?
- If...
Results
Medical records of 100 patients were audited.
Wells’ score was documented in 13% and could be retrospectively calculated in 85%.
Wells’ score was >2 in 6%. D-dimer was performed in 18%.
Ultrasound was indicated in 19% and not indicated in 34%.
The indication for ultrasound in 47% could not be determined due to non-availability of a Wells’ score (15%) or a D-dimer (32%). 13% had DVT. Wells’ score was available in 9% and would have led to the diagnosis in all. [Fig 1]
Conclusion
34% of Lower extremity DVT scans performed at TUH-ED met criteria for low value care as per the Australian Choosing Wisely recommendation and were potentially avoidable. We could not determine with certainty the indication for 47% of lower extremity DVT scans due to insufficient data.
Implementation of a TUH-ED clinical policy incorporating the use of Well’s DVT score would lead to a significant reduction in the number of low value care lower extremity ultrasound scans being performed at TUH-ED.
References
1. Choosing wisely Australia. 2015. Don’t request duplex compression ultrasound for suspected lower limb deep venous thrombosis in ambulatory outpatients unless the Wells Score (deep venous thrombosis risk assessment score) is greater than 2, OR if less than 2, D dimer assay is positive.. [online] Available at: <https://www.choosingwisely.org.au/recommendations/ranzcr2>
2. Scott IA, Duckett SJ. In search of professional consensus in defining and reducing low-value care. Med J Aust. 2015 Aug 17;203(4):179-81.