Advice
The technology
The technology
The microINR system (iLine Microsystems) is a hand-held point-of-care coagulometer. It is designed to measure international normalised ratio (INR) to show the clotting tendency of blood for people having oral anticoagulation therapy with vitamin K antagonist drugs.
The system includes a meter, microINR chips (disposable test strips), case, charger and plug adaptor. There are currently 2 meters available; the microINR meter and the microINR Link meter. The microINR chips can be used for both systems. The only difference is in their connectivity. The microINR Link offers the advantage of communicating through wireless Bluetooth technology to a software or smartphone application for data management. The disposable microINR chip is inserted into the meter and a finger prick sample of blood is applied to the chip. The chip dispenses a small amount of recombinant tissue factor reagent. As blood moves through the chip's capillary channels, it clots, and the blood flow slows. The INR is then determined by algorithms and an integrated machine vision system. The system is designed and approved for use by healthcare professionals as well as for self-monitoring by the user or carer.
Innovations
The microINR claims to offer a faster and more portable solution to monitoring and managing coagulation than laboratory‑based INR measurements. Alternative point-of-care coagulometers are available, but the microINR reports to be able to analyse INR from smaller samples of blood (minimum of 3 microlitres) than comparator devices (minimum of 8 microlitres). Also, microINR has Bluetooth capability. The device also offers automatic and individual calibration of each test to potentially minimise any risk of human error in testing.
Current care pathway
There are several conditions that may need treating with anticoagulation therapy, including atrial fibrillation and heart valve disease (congenital or acquired heart valve conditions), as well as those with venous thromboembolism.
Alternatives to standard anticoagulation therapy include non-vitamin K direct oral anticoagulants (apixaban, rivaroxaban, dabigatran etexilate), which have the benefit of not needing regular INR monitoring. However, this may be unsuitable for some people, such as those with mechanical heart valves, certain people with renal or liver dysfunction and may need consideration of other concurrent drugs that cannot be taken with non-vitamin K antagonist oral anticoagulants.
Those individuals who need vitamin K oral anticoagulants (warfarin) must have their INR measured regularly. Warfarin, especially if taken incorrectly, can cause severe bleeding (haemorrhages), therefore it is necessary to monitor blood coagulability. The frequency of monitoring may vary between daily and once every 12 weeks, depending on the stability of the INR.
In some cases, this monitoring is recommended to take place with venous plasma samples using the laboratory-based method. This includes conditions that can affect the activity of vitamin K antagonist oral anticoagulants such as primary and secondary antiphospholipid syndrome, high heparin concentrations and haematocrit out of the 25% to 55% range.
For those people with stable INR values within a standard range, their INR testing can take place by either laboratory-based plasma testing or using point-of-care test devices.
The following publications have been identified as relevant to this care pathway:
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NICE's key therapeutic topic on anticoagulants, including direct-acting oral anticoagulants (DOACs)
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NICE's guideline on atrial fibrillation: management (this is currently being reviewed, see the guideline in development)
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NICE's specialty guide on the management of anticoagulant services during the coronavirus pandemic
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NICE's guideline on venous thromboembolic diseases: diagnosis, management and thrombophilia testing.
Population, setting and intended user
The microINR system is suitable for individuals that need INR monitoring for their vitamin K anticoagulation therapy. Anticoagulation therapy services can be delivered in several different ways and mixed models of provision may be needed across a local health region. This could include full-service provision in secondary or primary care, shared provision, domiciliary provision, or by the individual with self-testing or self-management (collectively described as self-monitoring). Both primary and secondary settings may use either point-of-care tests or laboratory analysers in a central hospital laboratory shared provision setting. This variation means that anticoagulation monitoring may be delivered by a range of healthcare professionals including nurses, pharmacists, general practitioners, and individual users and or carers.
Costs
Technology costs
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The microINR and microINR Link meters cost between £299 and £470 (excluding VAT), varying across distributors. It has an expected lifespan of 5 years.
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Additional consumable costs include:
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microINR chips (disposable test strips) cost between £2.76 and £2.99 per strip, varying across distributors. One strip is needed per test and they can be purchased in boxes of 25 for £60.41 (excluding VAT).
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iLine EasyControl kit is for quality control purposes of the device, for use by health professionals only. This costs £69.94 (excluding VAT) and includes 5 × 2 ml bottles of control plasma, 5 bottles of calcium solution and 5 pasteur pipettes.
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Costs of standard care
Alternative point-of-care coagulometer devices cost between £299 and £590 (excluding VAT). Additional consumable costs include test strips ranging from £2.71 to £3.10 (excluding VAT) per strip. Monitoring control reagents for quality control purposes vary in their volume and costs. One comparator example was £24.20 (excluding VAT) for 4 bottles of 1.5 ml control solution, 4 pipettes and 1 code chip.
The cost effectiveness of comparator point-of-care tests compared with standard care were presented on page 101 of the NICE 2014 costing statement on the clinical and cost effectiveness of point-of-care tests. This stated the annual cost of self-monitoring with a point-of-care test to be £229.90 based on 35 tests per year and reduced to £127.81 per year if used in a self-management capacity. Because the costs of treating adverse events are considerably higher than those of self-monitoring, it was reported that avoiding a small number of high-cost adverse events has the potential to make the initial investment cost saving.
Resource consequences
The company states that the technology is currently used in 2 NHS trusts. The NICE 2014 costing statement reviewing this type of device estimated 450,000 people may be eligible for self-monitoring. Although an initial investment in the purchase cost over standard care is needed, evidence in similar devices suggests that this results in improved adherence to management, improved health outcomes and minimised costly hospital interventions to treat adverse incidents. There is the additional benefit of the reduction in face-to-face appointments for monitoring therefore releasing primary and secondary care resources for reallocation.
Training provided by the company to healthcare professionals is included in the cost of the device. Individuals who go on to self-test or self-manage at home will need training and ongoing support with relevant healthcare professionals which will have resource consequences. Further training materials such as videos and easy guides are provided by the company. Users with cognitive, visual, or physical impairments may need a care partner to be co-trained to assist. The company report that the device is designed to be easy to use and any learning curve for a new user (professional or lay) would be brief.