# Determination of the Precision of Glucometers Used in Saudi Arabia

## TL;DR

This study evaluates the accuracy of glucometers used in Saudi Arabia and finds that only one model meets precision standards, while others are affected by vitamin C interference.

## Contribution

The study identifies Accu-Chek Instant as the only glucometer meeting ISO precision standards and highlights vitamin C's significant interference with glucose readings.

## Key findings

- Only Accu-Chek Instant met ISO precision standards across all glucose concentrations.
- Vitamin C showed significant interference with glucose readings compared to acetaminophen and maltose.

## Abstract

What are the main findings?

The prevalence of self-monitoring blood glucose among individuals diagnosed with diabetes in Saudi Arabia is 95%, using commercially available glucometers.

Among the three glucometers tested, only Accu-Chek Instant met precision standards, while ConTour showed significant positive interference from vitamin C, exceeding acceptable bias limits.

What is the implication of the main finding?

Regular use of glucometers is widespread, underscoring the importance of evaluating device accuracy and reliability.

Certain glucometers may produce misleading glucose readings in the presence of interfering substances like vitamin C, highlighting the need for greater awareness among healthcare providers and patients.

Background: Efforts have been joined to set the parameters for the reliability of glucometers, yet once they are on the market, they are not further tested for the maintenance of accuracy, specificity, or precision. Methods: This comparative analytical study investigated the precision of commonly used glucometers in Saudi Arabia, namely Accu-Chek Instant®, On-Call Sharp®, and ConTour®, as well as the effects of vitamin C, acetaminophen, and maltose on glucose readings. Ten milliliters of blood was drawn in lithium heparin from healthy volunteers (n = 9). Six samples were divided into two groups of three. One group was designed for normal glucose levels. The second group was designed for high glucose levels by adding a dextrose solution. The last three samples were designed for low glucose levels by leaving the sample for 24 h at room temperature and then following with centrifuge and plasma extraction. Results: This study showed that only Accu-Chek Instant met the International Organization for Standardization (ISO) standard for precision across all dextrose concentrations, along with intra-class correlation values ranging from 0.95–1 (p < 0.001). By spiking the plasma samples with sub-therapeutic, therapeutic, and overdose concentrations of the metabolites, we found that vitamin C had a more evident interference on glucose readings compared to acetaminophen and maltose. Conclusions: The ascertainment of the precision of glucometers and the effects of interferences on them are vital in preventing the improper administration of insulin, which can lead to serious complications.