External quality assessment (EQA) for CoaguChek monitors.

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.