Evaluating Commutability of Control Materials in Three Nordic External Quality Assessment Schemes for Lipoproteins.

Background: The quality of control materials is crucial for evaluating external quality assessment (EQA) results. To detect method differences, the EQA material should behave the same as a patient sample, meaning the material must be commutable. Noncommutable materials may cause misinterpretations of EQA results.

Quantitative determination of cerebrospinal fluid bilirubin on a high throughput chemistry analyzer.

Background: Subarachnoid hemorrhage is a condition with high rates of mortality and morbidity. The diagnosis requires an urgent cerebral computed tomography scan and also a lumbar puncture if the scan fails to demonstrate intracranial blood. In Sweden the cerebrospinal fluid (CSF) is analyzed by spectrophotometric scanning for the presence of hemoglobin and bilirubin.