Laboratory performance in albumin and total protein measurement using a commutable specimen: results of a College of American Pathologists study.

Context: Discrepant results for serum constituents were observed among peer groups in the College of American Pathologists Comprehensive Chemistry Survey.

Objectives: To assess the performance of serum albumin and total protein measurement procedures and to evaluate the commutability of the conventional survey specimens.

Design: A fresh frozen, off-the-clot serum sample was included along with 4 conventional survey specimens.

The status of bilirubin measurements in U.S. laboratories: why is accuracy elusive?

In 2003, the Chemistry Resource Committee of the College of American Pathologists introduced a new specimen in the Neonatal Bilirubin Survey. The specimen, consisting of human serum enriched with unconjugated bilirubin and thus resembling a clinical specimen, brought about an improvement in the accuracy of the measurement of bilirubin by laboratories participating in the Neonatal Bilirubin Survey. There was also an improvement in the specificity of methods measuring direct bilirubin.

Interlaboratory comparison of the Doumas bilirubin reference method.

Objectives: To assess the performance of the Doumas bilirubin reference method.

Design And Methods: Ring trails using pooled patient specimens, a calibrator and human sera enriched with unconjugated bilirubin were analyzed in five laboratories using the Doumas bilirubin reference method.

Results: The coefficient of variation for the linear measurement range between laboratories ranged from 1-3%.

Laboratory performance in neonatal bilirubin testing using commutable specimens: a progress report on a College of American Pathologists study.

Context: In 2003 the Chemistry Resource Committee of the College of American Pathologists introduced a commutable specimen in the Neonatal Bilirubin Surveys. This specimen was intended to help evaluate all bilirubin methods.

Objective: To evaluate the effect of commutable specimens on the performance of selected clinical analyzers in measuring neonatal bilirubin from 2003 through 2006.

Bilirubin proficiency testing using specimens containing unconjugated bilirubin and human serum: results of a College of American Pathologists study.

Context: Specimens of the College of American Pathologists Neonatal Bilirubin and Chemistry surveys are inadequate for evaluating the performance of clinical laboratories in measuring serum bilirubin because they exhibit strong matrix interference. Recently published data indicate that at least 1 major clinical analyzer provided inaccurate bilirubin values for Neonatal Bilirubin Survey specimens. The composition of the specimens, bovine serum enriched with ditaurobilirubin, was responsible for the erroneous results.

Performance of bilirubin determinations in US laboratories--revisited.

Background: The diagnosis and management of hyperbilirubinemia in the newborn requires accurate and precise bilirubin determinations. We evaluated the current status of bilirubin measurements in US laboratories by examining data submitted by laboratories participating in the College of American Pathologists (CAP) Neonatal Bilirubin (NB) and Chemistry (C) Surveys.

Methods: We analyzed specimens from the CAP NB and C Surveys by the reference method for total bilirubin in three laboratories.