Abstracts of Meeting Papers

Performance of Second Generation Total and HDL Cholesterol Compact Measurement Systems.

The Cholestech (Hayward, CA) LDX compact analyzer measures total and HDL cholesterol on whole blood, plasma, or serum samples without pretreatment steps. The ChemTrak (Sunnyvale, CA) AccuMeter is non-instrumented and measures total cholesterol on whole blood samples. Neither device requires accurate pipetting of the blood sample. Capillary whole blood and venous heparinized whole blood samples were collected from 100 ambulatory donors and assayed with each device. Accuracy was evaluated by comparison to the venous plasma results from a CDC standardized enzymatic cholesterol and heparin-manganese HDL methods. Results ranged from 116-324 mg/dl, cholesterol, and from 17-105 mg/dl, HDL cholesterol. Average bias for total cholesterol was within +/- 2.1% for both devices, and for HDL cholesterol with the LDX was -1.0%, capillary, and -3.0%, venous samples. The total error for individual measurements was determined as the 95% tolerance interval (T1) for the mean % bias:

 

Capillary Blood

Venous Blood

LDX Cholesterol

-12.8 to 17.0%

-12.4 to 15.6%

LDX HDL

-21.2 to 19.2%

-17.6 to 11.6%

AccuMeter Cholesterol

-17.0% to 14.5%

-17.6 to 13.9%

The T1 includes both accuracy and precision components and represents the range of % bias which would include 95% of individual sample results with 95% probability. For this experimental design, the T1 consistent with NCEP 3% guidelines is +/- 11.5% and for 5% guidelines is +/- 17.3%. Both devices measured total cholesterol consistent with the NCEP 5% guidelines. There was no difference in cholesterol results between capillary and venous blood samples. The current CDC criteria for HDL cholesterol measurements are bias +/- 10% and CV