Authors' objectives:

The object of this report was to address the following research questions:

1a. What is the evidence of effectiveness (improved technical outcomes, improved clinical decision making, improved patient-relevant outcomes, and reduced harm) when non-radiologists use portable ultrasound (pU/S) devices for assessing abdominal trauma, abdominal aortic aneurysm (AAA), and ectopic pregnancy?

1b. What is the evidence regarding the effect of diagnostic accuracy on the effectiveness of these interventions?

1c. What is the evidence regarding the effect of user-dependent variables on the effectiveness of the intervention, specifically for the user (general practitioners, emergency physicians (EPs), and other nonradiologists), the type of training, the length of training, and previous experience in emergency U/S examinations?

2a. What guidelines exist regarding the use of these devices for the indications?

2b. What is the level of evidence supporting these guidelines?

2c. Are the recommendations in the guidelines consistent with the evidence?

3. What are the ethical and legal implications of using and reporting information from pU/S and other ultrasound imaging technologies?

Authors' results and conclusions: From 1,020 initial citations, 135 were identified as potentially meeting the selection criteria. After the full reports were reviewed, 49 were judged to have met the inclusion criteria. Of the 49 reports, 29 addressed Research Question 1a (clinical effectiveness of pU/S). The included studies were two comparative studies and 16 case series reports of pU/S for abdominal trauma; one case series report for AAA; three comparative studies and four case series reports for ectopic pregnancy; and three case series reports detailing more than one use. The quality of the identified primary studies was impaired by potential selection bias, differential use of a reference standard, or failure to use a blinded reference standard. For Research Question 1c, we identified six training guidelines and nine training programs. For Research Question 2a, two clinical practice guidelines and three systematic reviews were identified.

Authors' recommendations: Results suggest that the demonstrated benefits of ED pU/S performed by non-radiologists are limited to improving diagnostic certainty. We did not find convincing evidence that ED pU/S administered by a nonradiologist has an impact on outcomes that is relevant to patients? health. In this report, we were unable to identify compelling evidence of improving time to diagnosis or time to operative treatment. These patient-relevant outcomes are reported so infrequently that statements for or against ED pU/S are impossible to make. There is enough evidence from studies of blunt abdominal trauma, AAA, and ectopic pregnancy to suggest that ED pU/S performed by nonradiologists is an effective tool for improving diagnostic certainty. pU/S is likely to improve the certainty of diagnosis in an ED. These results are robust ? the estimated effect remains similar even when only studies of a higher quality are considered. The non-therapeutic advantages of using this technique are that it is easier to use and repeat, it is inexpensive to perform with the available technology, and it is non-invasive. There is evidence of misdiagnosis with pU/S, which is associated with inexperience. There is additional evidence of improved performance from non-radiologist physicians who undergo training. Training programs that use didactic and practical sessions (a minimum of 50 scans for each medical use) have shown improved effectiveness. Misdiagnoses with pU/S scans that are performed by trained non-radiologist physicians can still occur, but at rates akin to those observed in similar studies of radiologist-performed U/S scans. We were able to identify clinical practice guidelines for emergency U/S examinations for patients with abdominal trauma. None of the guidelines are specifically intended for nonradiologist physicians. Decisions to implement ED pU/S will need to be based on tacit knowledge and local guidance. Training and credentialing guidelines are important with respect to the ethical and legal requirements for emergency pU/S examinations that are performed by EPs, because guidelines for other specialties include topics that are not pertinent to emergency medicine. Training programs exist for the performance of U/S examinations. A training standard for physicians who use pU/S in the ED is important to ensure patient safety. Recommendations regarding the amount of continuing experience needed to maintain competence are essential. Additional prospective, comparative, high quality studies, designed to measure the impact of ED pU/S on efficiency, while monitoring clinical efficacy, would be helpful for making evidence-based decisions. The body of evidence describing diagnostic performance needs to be supplemented with results that demonstrate the effect of this intervention on diagnostic reasoning and time to definitive care.

Authors' methods: Overview

Project Status: Completed

URL for project: https://www.ccohta.ca/

Year Published: 2006

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Canadian Coordinating Office for Health Technology Assessment

Contact Address: 600-865 Carling Avenue, Ottawa, ON K1S 5S8 Canada. Tel: +1 613 226 2553, Fax: +1 613 226 5392;

Contact Name: requests@cadth.ca

Contact Email: requests@cadth.ca

Copyright: Canadian Coordinating Office for Health Technology Assessment (CCOHTA)