Comparison of three Dade-Behring Dimension AR machines in a clinical chemistry laboratory.

ABSTRACT

Three Dade-Behring Dimension AR Analyzers are presently in use in the Philippine General Hospital Department of Laboratories. One machine was acquired 2 years ago and two new ones were added recently. In order to determine whether the three machines would produce equivalent results 16 samples were selected for patients with hepatic and/or renal disorder. All 16 samples were tested for 16 different analytes. The results were subjected to tests for coefficient correlation, simple linear regression using slope and intercept and t-test for comparison. We concluded that for two assays (globulin and phosphorus), the values were sufficiently similar. For seven other assays (for total protein, albumin, sodium, potassium, chloride, calcium, and magnesium), the results were statistically significantly different, and for the remaining eight assays (total hiliruhin, direct bilirubin, AST, ALT, ALP, glucose, BUN, and creatinine), the values obtained were not ideal for drawing up conclusions about comparability. For the latter group of assays we plan to pool patient specimens of appropriate numbers and levels and repeat testing at some specified later date.