Analytic clinical chemistry precision and medical needs. The Canadian Interlab Program (CIP)

Precision obtained with two different serum pools used daily as internal quality-control specimens by 130 laboratories throughout Canada (Canadian Interlab Program) is reported for 14 analytes assayed by either manual or automated methods over a period of 16 months. Precision criteria set by Barnett to meet medical needs were not met for calcium, glucose, phosphorus, and urea nitrogen by more than 10% of the laboratories studied. Specific guidelines for laboratory precision are suggested for optimal and minimal performance in the assays of albumin, bilirubin, calcium, chloride, cholesterol, creatinine, glucose, phosphorus, potassium, sodium, total protein, triglyceride, urea nitrogen, and uric acid.