Acoustic Radiation Force Impulse Imaging
Health Technology Assessment Committee Recommendations¹
- Acoustic Radiation Force Impulse Imaging (ARFI) be publicly provided for the assessment of liver fibrosis in patients with hepatitis B and/or hepatitis C.
- Recognizing there are alternatives to ARFI (e.g. transient elastography), health authorities are best situated to determine the mix of technologies, the number of units (if any) and number of locations required to serve their respective patient populations when choosing to invest in ARFI.
- Use of ARFI beyond the assessment of liver fibrosis in patients with hepatitis B and/or hepatitis C not be permitted at this time, as other indications were beyond the scope of this review. Alternative indications should be assessed through the Health Technology Review process if there is health authority interest in expanding the scope.
Health Technology Assessment Committee Findings
- Hepatitis B and hepatitis C are highly infectious liver diseases that are associated with significant mortality and morbidity. Across British Columbia, there are an estimated 45,000 to 79,000 hepatitis B cases (17% of the Canadian total) and 53,000 hepatitis C cases (22% of the Canadian total). About 5% of hepatitis B and most hepatitis C cases become chronic, causing severe liver damage if not diagnosed and treated.
- Liver biopsy for diagnosing liver fibrosis is not without risk and is associated with significant patient anxiety, pain and lost productivity. Biopsies for patients with hepatitis B and hepatitis C have declined significantly in recent years.
- ARFI is not as well studied as transient elastography (Fibroscan) nor is it widely used in Canada; however, clinical evidence shows that diagnostic accuracy of ARFI compares favourably to liver biopsy in hepatitis C patients, although this finding is not as conclusive in hepatitis B patients. In addition, several studies conclude ARFI’s performance is not significantly different from transient elastography.
- With a software update, ARFI is able to be performed with existing ultrasound units, making it possible to be widely deployed and diffused within the health system. A preliminary analysis suggests that there are at least 100 ARFI capable ultrasound units in the province.
- Budget impact analysis suggests ARFI would result in cost savings compared to liver biopsy and transient elastography even if ultrasound units would need to be purchased to support the technology:
- It is estimated that if 11 units are purchased and 3,282 ARFI tests performed annually in viral hepatitis patients, and 382 (70%) of liver biopsies were avoided annually, ARFI would have a small annual net budget impact of $25,481 to health authorities. Based on the same parameters, transient elastography would cost health authorities $212,064 annually.
- Sensitivity analysis suggests that annual health authority costs would be between a savings of $5,000 and cost of $47,000 for ARFI and between $179,000 and $234,000 for transient elastography, depending on the number of biopsies averted and number of non-invasive liver tests performed.
- Evidence on cost-effectiveness is very limited. ARFI and transient elastography are similar in effectiveness therefore cost-effectiveness would be determined by the device that is lower in cost. As ARFI technology is embedded into existing ultrasound technology, it is often less costly than transient elastography (a certain number of transient elastography units have already been purchased).
- ARFI is not a duplication of transient elastography and both could have a role in the health system. ARFI could potentially enhance the ability to access non-invasive liver testing at more locations, sometimes in combination with other diagnostic tests.
- While risks are minimal, some attention should be given to implementation, should health authorities invest in either. ARFI is less costly and likely more easily diffused within the health system than transient elastography, however, some models of transient elastography are portable and particularly suitable in reaching more vulnerable populations like injection drug users. Other considerations include understanding local patient demand, capability of existing ultrasound units to support ARFI, and availability of sonographers.
- Approval of ARFI and transient elastography may increase demand beyond the number of patients historically assessed by liver biopsy and thus put pressure on the Pharmacare budget, particularly with respect to the new hepatitis C treatment options.
Health Technology Assessment Committee recommendations on Acoustic Radiation Force Impulse Imaging were accepted by a committee of senior health authority and ministry executives during March 2017. Please note health authorities determine how health technologies are implemented within their programs and services. Other relevant scientific findings may have been reported since the completion of the reference documents used to form the basis of the committee's recommendations.
¹ Estimated budget impacts are taken from the health technology assessment produced by the Health Technology Assessment unit based at the University of Calgary.