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External quality assessment (EQA) for CoaguChek monitors
Joergen Jespersen1, Leon Poller, A M H P van den Besselaar
1Department of Clinical Biochemistry, Hospital of South West Denmark.
Insights
External quality assessment (EQA) for CoaguChek monitors is crucial for accurate anticoagulation therapy. A simpler ECAA/ECAT EQA system identified significant deviations in 20.3% of devices, highlighting the need for regular monitoring.
Area of Science:
- Medical Devices
- Clinical Diagnostics
- Hematology
Background:
- Anticoagulant therapy monitoring is overwhelmed, leading to treatment delays.
- Point-of-care testing devices like CoaguChek are increasingly used for patient self-management.
- European Commission directives mandate external quality assessment (EQA) for patient self-monitoring devices.
Purpose of the Study:
- To assess the effectiveness of a simplified EQA system for CoaguChek monitors.
- To evaluate the performance of CoaguChek devices used in patient self-management.
- To determine the frequency of significant International Normalized Ratio (INR) deviations in CoaguChek monitors.
Main Methods:
- A collaborative assessment involving the European Concerted Action on Anticoagulation (ECAA) and European Concerted Action on Thrombosis (ECAT).
- Testing of 523 CoaguChek monitors across nine clinics using a standardized procedure.
- Utilized a set of 5 plasma samples with certified International Normalized Ratios (INR) for performance evaluation.
Main Results:
- A deviation of 15% or more from the certified INR on a single plasma sample defined unacceptable performance.
- 106 out of 523 tested monitors (20.3%) exhibited significant INR deviations.
- A higher incidence of deviations was noted with a specific lot of test strips.
Conclusions:
- Regular EQA of CoaguChek monitors is essential for ensuring accurate anticoagulation therapy.
- The simplified ECAA/ECAT EQA procedure effectively identifies monitors with unacceptable performance.
- Recommended EQA intervals are every six months or upon changing test strip lots.
Abstract:
Anticoagulant control facilities are being overwhelmed by requests for monitoring and large numbers of patients are not therefore receiving treatment. Procedures designed for point-of-care testing have therefore been developed, the most popular being the CoaguChek. The need for external quality assessment (EQA) of monitors used by patients in self-management has been stressed in a European Commission (EC) Directive. It would not however be feasible for all CoaguChek monitors to be enrolled in national or regional EQA schemes which take time to organise and analyse. The European Concerted Action on Anticoagulation (ECAA) has therefore evolved a simpler system. Its value has been assessed in collaboration with the European Concerted Action on Thrombosis (ECAT). 523 monitors were tested at nine clinics which asked patients to bring their CoaguChek instruments to be assessed with the ECAA/ECAT procedure based on a set of 5 plasma samples with certified international normalised ratios (INR). 15% or more deviation from the certified INR on a single certified plasma sample from the set was defined by the ECAA as the limit of acceptable performance. One hundred and six (20.3%) of the monitors tested showed significant deviation and higher than average incidence of significant INR deviations reported with one specific numbered lot of test strips. Recent ECAA/ECAT, Danish and Italian studies report regular EQA of CoaguChek monitors is essential. There is general agreement that this should be performed at reasonably frequent intervals, at six months or whenever there is a change of the manufacturer's test strips.
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