5.           Duplex Ultrasound for DVT

The principal purpose of this review was to consider the appropriate use of diagnostic imaging for PE and DVT. Appropriate use is defined as use which reaches a clinically meaningful diagnosis at a sufficient level of certainty in the least number of diagnostic steps, with due regard to patient safety, radiation dose, local expertise and accessibility, and cost to Medicare.

The recommendations are presented in item groups below, with higher priority groups presented first.

5.1        MBS items for duplex ultrasound for DVT

Table 3: Items for duplex ultrasound for DVT introduction table

Item

Descriptor

Schedule fee

55244

Duplex scanning, unilateral, involving B mode ultrasound imaging and integrated doppler flow measurements by spectral analysis of veins in the lower limb, below the inguinal ligament, for acute venous thrombosis, not being a service associated with a service to which an item in Subgroup 1 (with the exception of item 55054) or 4 applies (R)

$169.50

55221

DUPLEX SCANNING, unilateral, involving B mode ultrasound imaging and integrated Doppler flow measurements by spectral analysis of veins in the lower limb, below the inguinal ligament, for acute venous thrombosis, not being a service associated with a service to which an item in Subgroups 1 (with the exception of items 55026 and 55054) or 4 of this Group applies (R) (NK)

$84.75

 

55246

Duplex scanning, unilateral, involving B mode ultrasound imaging and integrated doppler flow measurements by spectral analysis of veins in the lower limb, below the inguinal ligament, for chronic venous disease, not being a service associated with a service to which an item in Subgroup 1 (with the exception of item 55054) or 4 applies (R)

$169.50

55222

DUPLEX SCANNING, unilateral, involving B mode ultrasound imaging and integrated Doppler flow measurements by spectral analysis of veins in the lower limb, below the inguinal ligament, for chronic venous disease, not being a service associated with a service to which an item in Subgroups 1 (with the exception of items 55026 and 55054) or 4 of this Group applies (R) (NK)

$84.75


5.2        MBS Data for DVT imaging

Table 4: MBS 2014-15 Statistics - Duplex ultrasound items for DVT

Items

55244

55221

55246

55222

Services 2014-15

299,191

405

127,318

276

Benefits 2014-15

$44.6 million

$33,019

$18.1 million

$17,084

2011-12 to 2014-15 growth in benefits

25.4%

8477.3%

17.4%

N/A

Number of patients

213,028

274

71,053

172

Number of providers

3,399

6

2,147

Less than 5

Source: Department of Health, published and unpublished data, based on date of processing data for financial year 2014-15

 

There were no concerns with the data provided for MBS items for DVT imaging, including data on the number of services for DVT items performed in 2014–2015 by requester's clinical specialty. The MBS data for the items was considered to be reasonable and compatible with clinically appropriate imaging use.

Table 5 Co-claiming of duplex scanning for DVT and chronic venous disease on the same patient same day (2014-15)

In 2014/15, same patient same day

 

Episodes

Number Services

Benefits Paid

Same or different providers

55246C, 55244T

2,356

5,911

$ 701,558

Other combinations of the duplex scanning for DVT and chronic venous diseases

93

228

$31,268

Total

2449

6139

$732,826

Same provider

55246C, 55244T

2,349

5,895

$ 699,005

Other combinations of the duplex scanning for DVT and chronic venous diseases

12

32

$1,856

Total

2,361

5,927

$ 700,861

Source: Department of Health, unpublished data, based on date of service using data processed up to 30 August 2015

Additional data on the number of services for DVT items requested by different provider specialities show that a larger number of services are requested, particularly in the primary care setting, where approximately 158,000 services were ordered by general practitioners during 2014–2015. This is compatible with appropriate clinical use of diagnostic imaging.

5.3        Issues

 The MBS Group I1 Ultrasound Subgroup 3 Vascular contains a number of items that describe the same procedure and have the same MBS fees for different vessels and for subsequent pathologies. Anecdotal evidence suggests that some providers have been claiming the wrong items of the same value due to the complexity of this part of the schedule.

 There was also concern that vascular imaging may be done for a screening purpose noting that, Medicare does not support screening ultrasound.

 The principal purpose of this review of duplex ultrasound for DVT was to consider:

- whether changes should be made to the MBS items to support the Choosing Wisely recommendations (below) for duplex compression ultrasound for suspected lower limb DVT

- whether the USA and Canada Choosing Wisely recommendations that do not support routine vascular ultrasound in post-operative knee and hip arthroplasty patients should be supported

- the necessity of having different ultrasound items for different vascular systems; and

- the appropriateness of co-claiming duplex scanning for acute DVT and chronic venous disease for the same patient on the same day.

5.4        Recommendation 1 MBS explanatory notes for the MBS items dealing with diagnostic imaging for DVT

5.4.1        Recommendation

 Introduce an MBS explanatory note stating that medical practitioners referring patients for duplex ultrasound for suspected lower limb DVT (items 55221, 55244) should read and consider the following Royal Australian and New Zealand College of Radiologists RANZCR 2015 Choosing Wisely recommendations:

- 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.

 

 Education of target referrers on the Choosing Wisely Recommendations should be implemented. The provision of educational strategies is not within the remit of the MBS but rather the MBS could leverage off educational strategies developed by the Colleges or a third-party organisation such as NPS MedicineWise whose primary role is to provide general education to health professionals.

 

5.4.2        Rationale

 The Choosing Wisely recommendations from the USA and Canada as they are currently written have not been supported.  There are several issues with scientific validity of the Choosing Wisely recommendations from the USA and Canada and the American Academy of Orthopaedic Surgeons (AAOS) guidelines as they apply to DVT US, in particular:

- these recommendations and guidelines do not allow for clinical situations where ultrasound requests are justified by clinical judgement.

- Choosing Wisely recommendations are biased in that they are orthopaedic-centric and make a number of unjustified assumptions about DVT ultrasound;

- AAOS guidelines do not reflect Australian practice

- AAOS guidelines are primarily concerned with reducing mortality rather than reducing morbidity and potential costs associated with post-surgery venous thromboembolism

 The Committee advised against restricting the use of duplex compression ultrasound only to the circumstances outlined in the RANZCR Choosing Wisely recommendations for suspected lower limb DVT, because doing so may inadvertently lead to poorer patient outcomes.  The RANZCR Choosing Wisely recommendations apply to ambulatory adult outpatients with suspected DVT who are not excluded from the Wells score on its exclusion criteria.  The RANZCR Choosing Wisely recommendations can’t be applied to non-ambulatory patients; paediatric or pregnant patients; inpatients; or patients excluded from the Wells score.

 The RANZCR Choosing Wisely recommendations for suspected lower limb DVT are based on the best evidence currently available to guide clinical practice. However, the Committee was concerned with:

- the availability of highly-sensitive D-dimer assays within varying health care settings

- that the RANZCR Choosing Wisely recommendations are not applicable to non-ambulatory patients; paediatric or pregnant patients; inpatients; or patients excluded from the Wells score.

- real world limitations on patients and resources.

 The Committee noted the USA and Canada Choosing Wisely recommendations that do not support routine vascular ultrasound in post-operative knee and hip arthroplasty patients. However, they recommended the inclusion of a statement in the MBS item descriptor or explanatory notes, stating that ultrasound is not to be used for screening, as sufficient to prompt consideration prior to requesting ultrasounds for DVT in post-operative knee and hip arthroplasty patients.

 While it is reasonable for referrers to be reminded to indicate the reasons for referral, enforcing the inclusion of clinical notes for investigation would be logistically difficult.

5.5        Recommendation 2 - Co-claiming duplex scanning for DVT and chronic venous disease

5.5.1        Recommendation

 Provide the following clarification on the appropriateness and application of co-claiming rules in the case of the same provider undertaking venous ultrasound for the same patient on the same day:

- it is inappropriate to claim ultrasound items for both acute DVT and chronic venous disease on the same leg in the same patient on the same day

- the only exception to the above recommendation is a patient being actively prepared with ultrasound for superficial varicose vein ablation (by whatever method), where the deep venous system of the same leg has to also be scanned on the same day to exclude fresh DVT

- the multiple services rules for diagnostic ultrasound apply and should be adhered to

5.5.2        Rationale

 MBS statistics suggested that, while the majority of patients only had one duplex scanning (either for DVT or chronic venous disease) within one day, there were 2,449 episodes (accounting for 0.38% of total services for item 55244) of co-claiming of duplex scanning for DVT and chronic venous disease on same day in 2014–15.

 The requirement to perform duplex scanning for acute DVT and for chronic venous disease  where both legs are examined in the same patient on the same day occurs very infrequently and therefore routine co-claiming of these two items is not appropriate clinical practice. However, co-claiming may occur when there are different providers involved. Therefore, there was consideration of the appropriateness of co-claiming for acute and chronic indications in the same patient on the same day when the same or different providers deliver this service.

 Acute DVT and chronic venous disease items are two alternative MBS items and therefore it is recommended that it is inappropriate to claim both items on the same leg of the same patient on the same day.

5.6        Recommendation 3 Redundant items for DVT imaging

5.6.1        Recommendation

It is recommended that a mechanism is identified to reduce the number of NK (services performed on old equipment), which duplicate regular items and lengthen the Diagnostic Imaging Services Table (DIST), as a class solution. The Committee will separately consult on recommendations about capital sensitivity.

 

5.6.2        Rationale

 A broader review of the vascular ultrasound items (Group I1 Ultrasound , Subgroup 3)with a view to fragment or consolidate MBS items is required and will be done at a later stage in the review.

 Fragmenting ultrasound items for different vascular systems offers a theoretical potential to collect utility data. However, the consolidation of MBS item numbers will simplify the DIST and will facilitate good clinical practice.