Point-of-care testing puts the result where the decision is made.
POCT moves measurement out of the central laboratory and to the patient's side. The trade-off is that quality assurance has to travel with it.
What POCT is
Point-of-care testing (POCT) is diagnostic testing performed close to the patient rather than in a central laboratory: at the bedside, in the consulting room, in an ambulance, or at home. Samples are usually small, a fingerstick of capillary blood, a few microlitres of whole blood or serum, and the analyser is compact and operated by clinical staff rather than laboratory scientists.
Its main advantage is time. A result available within minutes allows immediate clinical action, and that can change the outcome for the patient. Point-of-care testing has grown rapidly for exactly this reason.
The trade-off is control. In a central laboratory, accuracy is protected by trained operators, scheduled maintenance, internal quality control and external quality assessment. At the point of care, the same protection has to be built into the device and the material supplied with it.
Typical POCT settings
Emergency and acute care
Fast CRP or glucose readings support triage decisions before central laboratory results are available.
General practice
A result during the consultation allows treatment to start in the same visit.
Pharmacies and screening
Simple, decentralised measurement in settings with no laboratory infrastructure.
Home and remote monitoring
Chronic-condition monitoring, in particular glucose, outside any clinical building.
What quality control is for
A control is a specimen with a known expected value. Measuring it checks that the device, the reagent lot, the operator and the environment together still produce the right answer. Without that check, a drifting analyser produces plausible-looking numbers that no one questions.
What a good POCT control has to do
- Behave like a patient sample. A control in a human serum or blood matrix is commutable, it reacts on the device the way real samples do, so the check is meaningful. Artificial matrices can produce matrix effects that mask or imitate a problem.
- Stay stable. If the material itself changes during its shelf life, a shift in results says nothing about the device.
- Be the same in every vial. Vial-to-vial differences would be read as device imprecision.
- Be the same in the next lot. Consistent target values across lots keep long-term records comparable.
- Sit at clinically relevant levels. Performance matters most around the values used for clinical decisions.
- Be simple to run. Ready-to-use material removes the reconstitution step, and with it a source of operator error.
How a POCT control is run
Run the control like a sample
The control is measured on the device using the normal patient workflow. Verilox material is ready to use, so no reconstitution or dilution step is added.
Compare with the target
The measured value is compared with the assigned target value and its acceptance range for that lot and level.
Accept or investigate
Inside the range, the device and reagent lot are performing. Outside it, the cause is investigated before patient results are reported.
Record and trend
Results are recorded so drift can be seen over time, which only works if the control itself is stable and consistent between lots.
The framework we work within
ISO 13528
Provides the statistical methods used to check that a batch of control material is homogeneous. We select random vials after filling and evaluate them statistically before a lot is released.
Rilibäk
The German guideline of the Federal Medical Council for quality assurance in medical laboratory examinations. It defines total allowable error limits per analyte; we release CRP and glucose lots against those limits.
Our controls are supplied in bulk to IVD manufacturers, who package and label them for their own devices under their own regulatory approvals.
See the tests behind each lot →