EVALUATION OF 7 CHOLESTECH L.D.X ANALYZERS FOR TOTAL CHOLESTEROL DETERMINATIONS

We assessed the performance of seven Cholestech L . D . X lipid analyz ers under tightly controlled laboratory conditions for accuracy and pr ecision in accordance with analytical guidelines of the National Chole sterol Education Program (NCEP). Venous heparinized whole blood (VB) a nd plasma (VP), venous serum (VS), and capillary fingerstick whole blo od (FB) were collected from 18 individuals. Total cholesterol (TC) con centration was measured in VB, VP, and VS on all seven instruments. Th ree instruments were used for TC measurements of FB. Reference cholest erol values for each individual were generated in the same laboratory with a standardized method. The within-run coefficients of variation ( CVs) for all instruments with a Level I pool (1560 mg/L, n = 10) range d from 1.3% to 1.8% (mean = 1.59%). The between-run CVs with the same pool ranged from 2.2% to 3.4% (mean = 2.84%, n = 10). Correlation coef ficients derived from comparison of total cholesterol values generated by the instruments for each specimen type vs the reference cholestero l values were all >0.97. The average bias for all instruments for each sample type was 1.9% (FB), 4.3% (VB), 6.6% (VP), and 7.0% (VS). Predi cted cholesterol concentration for each sample type from regression cu rves for total cholesterol at the suggested NCEP clinical decision cut off values of 2000 and 2400 mg/L, respectively, were 2049 and 2431 mg/ L for FB, 2081 and 2469 mg/L for VB, 2122 and 2522 mg/L for VP, and 21 21 and 2521 mg/L for VS.