Background: Salivary cortisol is increasingly used in the diagnostic work-up of suspected Cushing’s disease as well as in stress research. In this study, the agreement of different methods for salivary cortisol measurement was assessed. Methods: Saliva samples from five healthy volunteers were distributed to three routine clinical chemistry laboratories. As a reference, all samples were also an...

CONTEXT In 1995, California adopted a bill that brought laboratory laws in line with the 1988 Clinical Laboratory Improvement Amendments' standards for clinical laboratories and mandated a study comparing results in physicians' office laboratories (POLs) with other settings. OBJECTIVE To determine whether persons conducting tests in POLs produce accurate and reliable test results comparable t...

The Ontario Laboratory Proficiency Testing Program has regularly monitored the analytical performance of total creatine kinase (CK) (approximately 230 participants) and CK isoenzyme-2 (CK-MB) (approximately 160 participants) throughout the entire province. Consistently, a wide dispersion of results has been observed not only between different analyzer systems but also among identical analyzers....

BACKGROUND Skin prick test is an important diagnostic procedure in clinical allergy but documentation of the quality is often missing. METHODS We describe a proficiency system to evaluate staff members in relation to the international recommended reproducibility in terms of coefficient of variation (CV < 40 %) and the linearity (coefficient of regression >0.85) based on blinded octuplicate hi...