Advice
Clinical and technical evidence
Clinical and technical evidence
A literature search was carried out for this briefing in accordance with the interim process and methods statement. This briefing includes the most relevant or best available published evidence relating to the clinical effectiveness of the technology. Further information about how the evidence for this briefing was selected is available on request by contacting mibs@nice.org.uk.
Published evidence
There are 5 studies summarised in this briefing, including 174 people.
All studies are observational, of which 3 were done retrospectively. The clinical evidence and its strengths and limitations are summarised in the overall assessment of the evidence.
Overall assessment of the evidence
The evidence for the technology is of low to moderate methodological quality, and most of the studies have small patient numbers. All studies evaluated the prognostic value of the Butterfly iQ+. Two studies had comparators, but they did not report patient outcomes. One study was done in the UK. The studies show that the Butterfly iQ+ can be effective as a diagnostic ultrasound tool across a variety of indications. Further evidence is needed comparing the Butterfly iQ+ with standard care, using a large sample size and reporting patient outcomes.
Bennett et al. (2020)
Key outcomes
In total, 34 paired lung ultrasound scans (LUS) on 18 people with COVID‑19 were included. There were 16 scans done in the severe respiratory impairment group, 11 in the moderate respiratory impairment group and 9 in the mild respiratory impairment group. LUS scores in individuals with mild respiratory impairment were significantly lower than in those with moderate and severe cases. No significant differences were found between LUS scores obtained with the Venue Go point‑of‑care ultrasound, and the Butterfly iQ+ portable pocket‑sized ultrasound, with a mean difference in score of 0.018 (plus or minus 0.018 points). The 2 technologies showed an excellent degree of concordance for all computed parameters.
Strengths and limitations
The authors state that this is the first study showing use of the Butterfly iQ+ portable pocket‑sized ultrasound in daily clinical practice in people with COVID‑19. It confirms the possible use of Butterfly iQ+ for this group. However, the authors recommend further research, because study findings are not specific and may not correlate with clinical outcomes.
Burleson et al. (2020)
Key outcomes
Five emergency physicians evaluated the performance of the Butterfly iQ+ and found that it performed well and met their needs for a point‑of‑care ultrasound. Advantages of using the Butterfly iQ+ included using a single probe for multiple modalities, good image quality in most indications and that it is relatively inexpensive. Disadvantages included large probe footprint, lower quality for cardiac imaging and frequent overheating.
Strengths and limitations
This study suggests that Butterfly iQ+ is an effective, but imperfect, point‑of‑care ultrasound device in a low resource emergency setting. This study has several limitations including not evaluating patient outcomes and having potential selection bias because patients were scanned at the discretion of the clinician.
Rajendram et al. (2020)
Key outcomes
Image quality was interpretable by all the study sonographers. The backup ultrasound machine was not needed. There were no disagreements between the study sonographers in any of the ultrasound findings. As a result, all investigators considered that the objectives of the present study had been fulfilled, and that further investigation was unnecessary.
Strengths and limitations
This study combined Butterfly iQ+ with lung ultrasound, vascular ultrasound and limited transthoracic echocardiography with saline microbubble contrast. It suggested that this combined approach can identify the aetiology of shunt. Results for Butterfly iQ+ were presented separately and then combined with the results of the other approaches.
Houze et al. (2020)
Study size, design and location
Observational study in 19 people with kidney disease in Grenada.
Key outcomes
Butterfly iQ+ confirmed clinical diagnosis in 9 out of 19 people. In 10 people, Butterfly iQ+ led to new diagnoses. Some examples include clinical diagnosis of kidney failure, which was changed to bilateral hydronephrosis in 1 case and renal cyst with no hydronephrosis in another case after point‑of‑care ultrasound (POCUS).
Knight et al. (2020)
Study size, design and location
Retrospective service evaluation in 100 people when COVID-19 was suspected in the UK.
Key outcomes
In 92 people, the clinical features and ultrasound examination were considered to be consistent with COVID‑19. Quality of image acquisition was rated as good in 55.4% (n=51), average in 41.3% (n=38), and poor in 3.3% (n=3). SARS‑CoV2 nasopharyngeal swab results were positive in 42.4% of cases (n=39). The risk of all‑cause mortality in people with scores in the lowest quartile was 2.5% (95% confidence interval [CI] 0.12% to 12.95%) compared with 42.9% (95% CI 15.8% to 75.0%) in the highest quartile. POCUS‑assessed severity correlated with length of stay and duration of supplemental oxygen therapy.
Strengths and limitations
This study suggests that this new POCUS severity scale showed good discriminatory performance in predicting a range of adverse outcomes in people with suspected COVID‑19. POCUS was done on an ad hoc basis at the discretion of the clinician, allowing for selection bias. This study used 2 POCUS devices, the Butterfly iQ+ and the LOGIC E9 machine. However, the results are not stratified by device, so it is unclear how often each device was used and what the outcomes for each device were. There was also no comparison between the 2 devices.
Sustainability
The company claims the single probe is reusable but has to be cleaned with approved disposable liquid saturated wipes and disinfected with approved disposable wipes or disinfection solution. At the end of life, the probe and accessories can be recycled. There is no published evidence to support these claims.
Recent and ongoing studies
-
COVID-19 and lung ultrasound utility. ClinicalTrials.gov Identifier: NCT04591158. Status: recruiting. Indication: lung infection, COVID‑19. Devices: Butterfly iQ+. Last updated: October 2020. Country: Canada.
-
Pain after preoperative ultrasound guided hip injections for total hip arthroplasty (PUSH). ClinicalTrials.gov Identifier: NCT04219098. Status: not yet recruiting. Indication: total hip replacement, arthroplasty. Devices: Butterfly iQ+ and standard care. Last updated: January 2020. Country: US.
-
Comparing an inexpensive handheld ultrasound machine and a large mobile ultrasound system. ClinicalTrials.gov Identifier: NCT03764111. Status: completed. Indication: pregnant women needing a routine obstetric scan. Devices: Butterfly iQ+ and Sonosite M‑turbo. Completed: December 2020. Country: US.
-
Preclinical medical student echocardiography training American Society of Echocardiography curriculum. ClinicalTrials.gov Identifier: NCT04083924. Status: completed. Indication: cardiac ultrasound in people who are healthy. Devices: Butterfly iQ+. Completed: May 2020. Country: US.
-
Implementing digital health in a learning health system (ASE-INNOVATE). ClinicalTrials.gov Identifier: NCT03713333. Status: unknown. Indication: cardiovascular diseases, hypertension, heart failure, atrial fibrillation, metabolic syndrome, genetic disease. Devices: Butterfly iQ+. Last updated: October 2018. Country: US.