System accuracy evaluation of FORA Test N Go Blood Glucose Monitoring System versus YSI 2300 STAT Plus glucose analyzer following ISO 15197:2013

Transcription

1 System accuracy evaluation of FORA Test N Go Blood Glucose Monitoring System versus YSI 2300 STAT Plus glucose analyzer following ISO 15197:2013

2 Abstract Objective: The goal of the study was to assess the accuracy and reliability of Fora Test N Go blood glucose monitoring system (BGMS) in the clinical studies according to the international standard ISO 15197: 2013(E) criteria and more stringent guidelines. Methods: The capillary blood specimens was collected via fingertip stick from participants at AMCR Institute (700 West El Norte Parkway, Suite 201, Escondido, CA 92026) and tested on three different lots of test strips. Results: The Fora Test N Go BGMS met the requirements of ISO 15197:2013 from all three lots of test strips tested. Within ± 5 mg/dl & ± 5 % (Within ± 0.28 mmol/l & ± 5 %) & ± 10 % (Within ± 0.56 mmol/l & ± 10 %) Within ± 15 mg/dl & ± 15 % (Within ± 0.83 mmol/l & ± 15 %) 425 / 600 (71.0 %) 579 / 600 (96.5 %) 592 / 600 (98.6 %) This BGMS is also compliant with the requirements of DIN EN ISO 15197:2003 with all 3 reagent system lot(s). Within ± 5 mg/dl & ± 5 % (Within ± 0.28 mmol/l & ± 5 %) & ± 10 % (Within ± 0.56 mmol/l & ± 10 %) & ± 15 % (Within ± 0.56 mmol/l & ± 15 %) Within ± 15 mg/dl & ± 20 % (Within ± 0.83 mmol/l & ± 20 %) 336 / 600 (55%) 518 / 600 (86.0 %) 587 / 600 (98.0 %) 598 / 600 (99.6 %) Conclusion: The study suggest that the Fora Test N Go blood glucose monitoring system not only met the current accuracy standard (ISO15197:2003), but also met with the minimum acceptable accuracy standard published in the newer 2013 guideline (ISO15197:2013) when compared the test results with a laboratory reference. 2

3 1. Introduction This study was to evaluate the system accuracy following ISO 15197: protocol and if possible, the newly published ISO 19197: guideline. EN ISO 15197:2003 is an international standard published by International Standard Origination (ISO) specifying requirements for in vitro glucose monitoring systems on self-testing in managing diabetes mellitus. The minimum acceptable accuracy for results produced by a glucose monitoring system shall be as follows: Ninety-five percent (95 %) of the individual glucose results shall fall within ± 15 mg/dl (± 0.83 mmol/l) of the results of the reference measurement at glucose concentrations < 75 mg/dl (< 4.2 mmol/l) and within ± 20 % at glucose concentrations 75 mg/dl ( 4.2 mmol/l). In 2013, ISO has published a newer standard ISO 15197:2013 (E) which tightens the accuracy acceptance criteria. The minimum acceptable accuracy for results produced by a glucose monitoring system has been changed to the followings: Ninety-five percent (95 %) of the individual glucose results shall fall within ± 15 mg/dl (± 0.83 mmol/l) of the results of the reference measurement at glucose concentrations < 100 mg/dl (< 5.55 mmol/l) and within ± 15 % at glucose concentrations 100 mg/dl ( 5.55 mmol/l). EN ISO 15197: 2003 ISO 15197: 2013 (E) Maximum deviation from glucose reference value At glucose levels < 75 mg/dl (< 4.2 mmol/l) At glucose levels 75 mg/dl ( 4.2 mmol/l) ± 15mg/dl (0.83 mmol/l) ± 20% At glucose levels < 100 mg/dl (< 5.5 mmol/l) ± 15mg/dl (0.83 mmol/l) ± 15% Parkes Error Grid Not Required At glucose levels 100 mg/dl ( 4.2 mmol/l) 99% of results within Zones A and B 2. Material and Methods 2.1 Reference standard The reference used in this study was a Yellow Springs 2300 (YSI 2300) manufactured by YSI incorporated (Yellow Springs, OH) which detected glucose concentration based on a glucose oxidase method The readings of the YSI analyzer was validated by running the analyzer with the National Institute of Standards and Technology (NIST) secondary reference material SRM 965a which consists of four levels of standard glucose concentrations. Glucose reference was determined as the average of at least duplicated measurements from the YSI. 3

4 2.2 Preparation of Samples Capillary blood samples were collected based on the ISO 15197:2013 guideline to have certain percentage of subject samples in the following concentration categories: Concentration category Percentage of samples [%] Glucose concentration [mg/dl (mmol/l)] Number of test subjects based on ( 2.77) > (> ) > (> ) > (> ) > (> ) > (> ) > 400 (> 22.20) Test of Blood Glucose Sample capillary blood was obtained by a finger stick using a 25G safety lancet. The blood sample was immediately collected onto a Lithium-Heparin Microvette (~ 200 μl) The capillary blood was then placed on a parafilm and tested on Fora Test N Go blood glucose monitoring systems (6 devices per station with test strip lot 1, 2, and 3). The remaining blood in the lithium-heparin microvette was then immediately placed on a centrifuge to separate plasma. The glucose concentration of the plasma was then determined by the YSI 2300 using one electrode. The measurement was repeated once and the true glucose concentration of the subject glucose was determined by the average of the YSI values. 2.4 Statistical analysis In this study, the following statistical analyses were performed: Bias analysis according to Bland and Altman 5. Regression analysis according to Passing and Bablok Results 3.1 Test results Accuracy results following ISO 15197:2013 (E) Summary: Within Consensus Error Grid zones A and B 600 / 600 (100 %) Conclusion: The Fora Test N Go BGMS met the requirements of new ISO standard (ISO 15197:2013). 4

5 Detail results: System accuracy results for glucose concentrations < 100 mg/dl (5.55 mmol/l) Within ± 5 mg/dl (Within ± 0.28 mmol/l) (Within ± 0.56 mmol/l) Within ± 15 mg/dl (Within ± 0.83 mmol/l) 47 / 64 (73.4 %) 61 / 64 (95.3 %) 64 / 64 (100 %) 50 / 64 (78.1 %) 61 / 64 (95.3 %) 63 / 64 (98.4 %) 49 / 64 (76.6 %) 64 / 64 (100 %) 64 / 64 (100 %) System accuracy results for glucose concentrations 100 mg/dl (5.55 mmol/l) Within ± 5 % Within ± 10 % Within ± 15 % 72 / 136 (52.9 %) 118 / 136 (86.8 %) 134 / 136 (98.5 %) 59 / 136 (43.4 %) 109 / 136 (80.2 %) 136 / 136 (100 %) 64 / 136 (47.1 %) 108 / 136 (79.4 %) 130 / 136 (95.6 %) Accuracy results following ISO 15197:2003 Summary: Within Consensus Error Grid zones A and B 600 / 600 (100 %) Conclusion: Fora Test N Go BGMS also is in compliance with the requirements of DIN EN ISO 15197:2003 for all 3 reagent system lot(s). Detail results: System accuracy results for glucose concentrations < 75 mg/dl (4.2 mmol/l) Within ± 5 mg/dl (Within ± 0.28 mmol/l) (Within ± 0.56 mmol/l) Within ± 15 mg/dl (Within ± 0.83 mmol/l) 29 / 38 (76.3 %) 36 / 38 (94.7 %) 38 / 38 (100 %) 32 / 38 (84.2 %) 35 / 38 (92.1 %) 37 / 38 (97.4 %) 31 / 38 (81.6 %) 38 / 38 (100 %) 38 / 38 (100 %) System accuracy results for glucose concentrations 75 mg/dl (4.2 mmol/l) Within ± 5 % Within ± 10 % Within ± 15 % Within ± 20 % 88 / 162 (54.3 %) 142 / 162 (87.7 %) 160 / 162 (98.8 %) 161 / 162 (99.4 %) 75 / 162 (46.3 %) 134 / 162 (82.7 %) 162 / 162 (100 %) 162 / 162 (100 %) 81 / 162 (50.0 %) 133 / 162 (82.1 %) 156 / 162 (96.3 %) 162 / 162 (100 %) 5

6 3.1.3 Consensus Error Grid for FORA Test N Go with three reagent system lots Region Number Percent A % B % C % D % E

7 Summary of regression analysis (Passing and Bablok) n=200 Regression Reagent system lot 1: TD14D228-C0E Reagent system lot 2: TD14 D828-C0E Reagent system lot 3: TD14 D928-C0E Y= X Y= X Y= X 7

8 3.2.4 Absolute differences between FORA Test N Go and YSI 2300 STAT PLUS 8

9 4. Conclusion and discussion: This study showed that the Fora Test N Go blood glucose monitoring system not only met the current accuracy standard (ISO15197:2003), but also exceeded the minimum acceptable accuracy standard published in the newer 2013 guideline (ISO15197:2013) when compared the test results with a laboratory reference. In addition, 99% of the data points fall within Zone A & B of Consensus Error Grid, which means that when user obtained a value using Fora Test N Go monitor, it should not result in a clinical decision that could be deemed inappropriate. There are several glucose monitoring systems out in the market. Since FDA is in preparation of tightening the accuracy standard to ± 15% by adopting the new ISO15197:2013 standard. Based on the results, it will be reasonable assumption that Fora Test N Go met the new ISO standard, and therefore would be a reasonable selection for users if they like to use meter with a higher accuracy. Reference a International Diabetes Federation, the global burden. b. In vitro diagnostic test systems - Requirements for blood-glucose monitoring systems for self-testing in managing diabetes mellitus. EN ISO 15197:2003. c. In vitro diagnostic test systems - Requirements for blood-glucose monitoring systems for self-testing in managing diabetes mellitus. ISO 15197:2013. d. Parkes JL, Slatin SL, Pardo S, Ginsberg BH: A new consensus error grid to evaluate the clinical significance of inaccuracies in the measurement of blood glucose. Diabetes Care 2000; 23: e. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986; 1: f. Passing H, Bablok. A new biometrical procedure for testing the equality of measurements from two different analytical methods. Application of linear regression procedures for method comparison studies in clinical chemistry, Part I. J Clin Chem Clin Biochem 1983; 21: