Verifying measurements on Siemens Atellica® instruments using clinically acceptable analytical performance specifications.

Measurements on clinical chemistry analysers must be verified to demonstrate applicability to their intended clinical use. We verified the performance of measurements on the Siemens Atellica® Solution chemistry analysers against the clinically acceptable analytical performance specifications, CAAPS , including the component of intra-individual biological variation, CV I . The relative standard uncertainty of measurement, i.e. analytical variation, CV A , was estimated for six example measurands, haemoglobin A 1c in whole blood (B-HbA 1c ), albumin in urine (U-Alb), and the following measurands in plasma: sodium (P-Na), pancreatic amylase (P-AmylP), low-density lipoprotein cholesterol (P-LDL-C), and creatinine (P-Crea). Experimental CV A was calculated from single-instrument imprecision using control samples, variation between measurements on parallel instruments, and estimation of bias with pooled patient specimens. Each obtained CV A was compared with previously developed CAAPS . The calculated CV A was 1.4% for B-HbA 1c ( CAAPS 1.9% for single diagnostic testing, CAAPS 2.0% for monitoring after duplicate tests; IFCC units), 10.9% for U-Alb ( CAAPS 44.9%), 1.2% for P-Na ( CAAPS 0.6%, after triplicate testing 1.5%), 8.2% for P-AmylP ( CAAPS 22.9%). The CV A was 4.9% for P-LDL-C ( CAAPS for cardiovascular risk stratification 4.9% after four replicates), and 4.2% for P-Crea ( CAAPS 8.0%). Three of the six measurands fulfilled the estimated clinical need. Results from P-Na measurements indicate a general need for improving the P-Na assays for emergency patients. It is necessary to consider CV I when creating diagnostic targets for laboratory tests, as emphasised by the CAAPS estimates of B-HbA 1c and P-LDL-C.