It is relatively easy for any device to perform well under ideal conditions. The harder and more clinically meaningful question is whether a CGM sensor performs well every day, in every patient, across the full wear period. Consistency, not peak performance, is the real benchmark.
Why Consistency Matters More Than Isolated Accuracy Peaks
In a clinical evaluation, a sensor might be tested under controlled conditions with a rested patient, ambient temperature, and a freshly inserted sensor. Real-world use looks nothing like this. Patients sleep on their sensors, exercise, eat unpredictably, experience illness, travel across time zones, and forget to check their phones. A device that performs brilliantly in a lab but inconsistently in life creates a more dangerous situation than one whose limitations are at least predictable.
For clinicians, inconsistency introduces a form of uncertainty that is difficult to manage. If a sensor’s readings are reliable on day two but less so on day seven, there is no clear clinical guidance for when to trust the reading and when to verify it. This ambiguity erodes confidence in the technology and in the clinician’s ability to use it as a basis for therapeutic decisions.
What 77,000 Data Points Show
Dexcom One+ has been validated across more than 77,000 glucose reference points. This a data set large enough to draw meaningful conclusions about real-world consistency, not just controlled performance. This includes data across diverse patient populations, multiple wear sites, and the full range of glucose values a person with diabetes is likely to encounter in daily life.
The findings show that Dexcom One+ maintains greater than 95% of readings within the 20/20 accuracy threshold across the full 10.5-day wear period. Day-by-day analysis confirms that MARD does not meaningfully degrade from day two through day ten. For HCPs advising patients, this means that a patient’s reading on the eighth day of a sensor is as reliable a basis for a clinical decision as a reading on the second day.
Consistency in Alert Performance
Accuracy and consistency are inseparable from the alert system that depends on them.
Dexcom One+ features Low, High, and Urgent Low alerts, alarms that are only as useful as the data underpinning them. A sensor with inconsistent accuracy generates false alerts or, more dangerously, fails to alert when it should. Both outcomes undermine patient trust and clinician confidence.
Consistent accuracy means consistent alert performance. Patients who know that a Low alert reliably signals a real glucose drop (and not a sensor artefact) can respond to those alerts appropriately. Those who have experienced too many false alarms, on any device, learn to ignore them. Consistency in performance is what prevents alarm fatigue from becoming a patient safety risk.
Consistency Across Populations
One of the most demanding tests of CGM consistency is performance across diverse user groups. Dexcom One+ validation data includes paediatric populations which is a group where glucose management is often more variable and where the consequences of monitoring gaps are more acute. This inclusion reflects a commitment to performance that holds across patient types, not just the average adult.
For South African clinicians managing patients across a broad socioeconomic and lifestyle spectrum (urban professionals, rural communities, patients with varying comorbidities) this breadth of validation matters. A sensor that performs consistently for a well-controlled patient in a private practice setting should perform equally consistently for a patient in a public sector facility who checks their data once a day rather than once an hour.
The Clinical Case for Consistency
Consistency in CGM performance is the quality that allows data to become trust. A single accurate reading is useful. A pattern of consistently accurate readings over days, across patients, in real-world conditions is what allows a clinician to make therapeutic decisions with confidence and a patient to live their life without the low-grade anxiety of wondering whether what they are seeing is real.
This is the standard to which Dexcom One+ is held, and the standard against which it should be evaluated. Not whether it performs well today, but whether it performs well on day ten. Not whether it works for one patient, but whether it works for the full spectrum of patients who depend on it.
