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 firstname.lastname@example.org.
Two studies are summarised in this briefing, that are considered the most relevant to the technology. They include 1 cross-sectional study (full text) and 1 comparative study (conference abstract). The selected studies include 1,270 blood samples (Duhalde et al. 2019, full text) and 1,671 people (Duhalde et al. 2019, abstract) who presented to emergency department.
The clinical evidence with its strengths and limitations are summarised in the overall assessment of the evidence.
The evidence for Helge is limited in quantity and quality. The studies were done in Sweden and so the generalisability of the evidence to the NHS may be limited.
The primary outcomes include diagnostic accuracy and the incidence of haemolysis detected using Helge compared with routine haemolysis detection tests in the laboratory. Available studies report the diagnostic accuracy and the incidence of haemolysis in the blood samples. However, there are no data on subsequent clinical outcomes and the resource impact of the test.
A cross-sectional study done in Sweden of 1,270 blood gas samples from people presenting to the emergency department as part of routine care.
Haemolysis was defined as more than 50 mg/100 ml free haemoglobin in plasma. This was present in 7.9% (n=100) of all study samples. The point-of-care method identified haemolysed samples with a sensitivity of 80% and a specificity of 99% compared with the routine method. The positive and negative predictive values were 89% and 98%, respectively.
The haemolysis detection was done immediately after blood gas analysis. There is no gold standard reference test; the study defined haemolysis as more than 50 mg/100 ml free haemoglobin in plasma. Two study authors had a conflict of interest (1 author is the founder of the company and the other author is employed by the company).
A cross-sectional study in Sweden of 1,671 people who attended the emergency department.
Helge was used in the intervention group. The comparator was routine haemolysis method in the hospital laboratory.
Of all samples included, haemolysis was detected in 7.9% of people in the intervention group and 12.3% people in the control group. Of samples collected by different methods, haemolysis incidence was 21.3% using: peripheral venous catheter, 2.4% using butterfly needle and 1.6% using straight needle. Risk of haemolysis assessed by nurses during blood sample collection correlated to observed blood flow: 35.9% in slow flow samples, 15.7% in fast flow samples, and 8.0% in normal flow samples. Nurses' haemolysis rates varied between 2.7% and 18.6%.
The company claims that the use of Helge can reduce the need for repeat tests, and so potentially reduce usage of some materials such as needles, vacuum tubes, syringes and reagents. As a point of care test, Helge can avoid transportation of samples to the lab. There is no published evidence to support these claims.
The company noted that a recent study has been completed, but there is very limited information available. A Hemcheck press release about the recently completed study has more information.