Accusport/Accutrend Lactate Accuracy Information

The accepted method of validating a new instrument to measure lactate is to take simultaneous measurements from a subject and then to compare the results of the test instrument (in this case, the Accusport/Accutrend Lactate Portable Lactate Analyzer) with an instrument of known accuracy. Except for one study conducted on hospital trauma patients, all the Accusport readings were made on people while they were exercising. At the same time an additional measurement was taken using an instrument with established validity. The Accusport portable lactate analyzer and the Accutrend Lactate analyzer use the same technology. The tests below were conducted by various organizations in the United States and Europe to validate the accuracy of the Accusport.

Tests 1 and 2 were conducted for the European introduction of the Accusport.

Test 1	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
4 Sites	Whole Blood	Accusport = .994 TCL + 0.055	R = .969	N = 418	.8 - 18
Comments	Blood was sampled from each ear. One sample was used for the Accusport the other sample was used for the Test Combination Lactate for Sports Medicine (TCL). The TCL is a fully enzymatic photometric method. A blood drop was used for the Accusport while 20 µl of blood was used for the TCL.

Test 2	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
6 Sites	Plasma	Accusport = .949 TCL - 0.039	R = .982	N = 617	.7 - 25
Comments	Blood was sampled from each ear. One sample was used for the Accusport the other sample was used for the Test Combination Lactate for Sports Medicine (TCL). A blood drop was used for the Accusport. Capillary blood was centrifuged within 1 minute and deproteinated with perchloric acid. The resultant plasma was measured by the TCL.

Test 3, 4 and 5 were conducted for the US introduction of the Accusport.

Test 3	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
Lot 1	Whole Blood	Accusport = 1.014 TCL - 0.1	R = .991	N = 98	.7 - 15
Lot 2	Whole Blood	Accusport = .972 TCL + 0.4	R = .989	N = 98	.7 - 15
Comments	Deproteinized capillary whole blood was used as the reference. The TCL was used on the EPOS analyzer. Samples were from earlobes.

Test 4	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
Lot 3	Whole Blood	Accusport = .999 YSI - 0.5	R = .966	N = 108	.9 - 17
Lot 4	Whole Blood	Accusport = .913 YSI + 0.1	R = .954	N = 108	.9 - 17
Comments	Hemolyzed capillary whole blood was used as the reference. The YSI Sport 1500 was used as the reference device. Samples were taken from finger tips.

Test 5	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
Lot 1	Plasma	Accusport = .971 TCL - 0.2	R = .98	N = 98	.5 - 20
Lot 2	Plasma	Accusport = .946 TCL + 0.3	R = .984	N = 84	1 - 21
Comments	Deproteinized capillary plasma was used as the reference. The TCL was used in the manual method on a photometer. Samples were from earlobes.

Tests 6, 7, and 8 were presented at the 1996 American College of Sports Medicine meeting.

Test 6	Testing Mode	Average Value	Correlation Coefficient	Sample Size	Range mmol/l
Lot 1	Whole Blood	Accusport = 4.95; YSI = 5.44	R = .934	N = 96	.5 - 17
Lot 2	Whole Blood	Accusport = 5.03; YSI = 5.44	R = .954	N = 96	.5 - 17
Comments	Testing was conducted during a graded exercise test. Capillary whole blood was used as the sample. The YSI was used as the reference instrument. Samples were from finger tips.

Test 7	Lactate Rest	Lactate 70% VO2	Lactate Peak	Lactate 1 Min Post	Lactate 5 Min Post
Accusport 1	1.44	2.26	13.17	14.86	12.78
Accusport 2	1.24	2.24	13.95	14.66	12.73
YSI 1500	1.17	2.14	13.21	14.52	13.61
Interclass Correlations	.80	.93	.88	.89	.97
Comments	31 well trained cyclists performed a graded exercise test followed by a Wingate anaerobic test. Lactate measurements were taken at rest before the graded exercise test, at 70% VO2 and at Peak power output. After a rest a Wingate test was performed and lactate measurements were taken at 1 and 5 min post test while performing an active recovery. All lactate reading were from capillary whole blood taken from the finger tips. The YSI 1500 was the reference analyzer. The interclass correlations were very high considering that each class represented a narrow range of readings

Test 8	Testing Mode	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
Lot 1	Whole Blood	Not Available	R = .976	N = 133	.7 - 17
Lot 2	Whole Blood	Not Available	R = .976	N = 133	.7 - 17
Comments	Testing was conducted during a graded exercise test. Capillary whole blood was used as the sample. The YSI 1500 was used as the reference instrument. Samples were from finger tips. The Accusport readings were from 10 different meters and show the reliability of readings across different instruments.

Test 9 was conducted by a major teaching hospital in the Northeast part of the US. The results were presented at the Critical Care Medicine Conference in February 1997.

Test 9	Regression Equation	Correlation Coefficient	Sample Size	Range mmol/l
Accusport 1 vs Nova 10	Accusport = .861 Nova + .209	R = .988	N = 63	.10 - 19
Accusport 2 vs Nova 10	Accusport = .929 Nova - 0.095	R = .991	N = 66	.10 - 19
Accusport 1 vs 2	Accusport2 = .92 AS 1 + 0.323	R = .991	N = 63	.10 - 18
Comments	This study took place in a hospital trauma center and the subjects were trauma victims. While there were a few high readings, nearly all the readings (57) are under 7 mmol/l. Given this narrow range the high correlations between the two Accusport analyzers and the Nova 10 instrument are very impressive. All readings were of whole blood. The Nova 10 readings were taken by hospital lab personnel and the Accusport readings were taken by a medical student.