Recent studies of D-dimer as a “rule-out” test for deep venous thrombosis (DVT) frequently have used duplex ultrasound rather than venography as the gold standard. Because duplex ultrasound has limited ability to image the calf veins, there is potential for ultrasound studies to classify patients with calf DVT as...

The discriminative ability of a diagnostic procedure is called diagnostic accuracy, and a number of quantitative measures out of which sensitivity and specificity are mostly used in the biomedical literature can express it. Each diagnostic-accuracy measure relates to some specific aspects of a diagnostic procedure....

This is the second of two articles focusing on the reference interval, the most widely used tool for interpretation of patient test results.  The first [1] was an introduction to the theoretical concepts that underpin the significance, construction and use of reference intervals. Here consideration is given to the...

As point-of-care applications of lab testing demand more rapid and clinically integrated order entry and results-reporting processes, it becomes paramount for the laboratory to investigate entire clinical processes. Direct observation and process mapping of these clinical applications – end to end - are "lean" tools...

Applications of point-of-care testing (POCT) for diagnostic biomarker measurement in healthcare have increased significantly in recent years in a wide range of clinical scenarios. These include infectious disease, critical care, cardiology and other areas of emergency medicine. Traditionally, routine clinical...

Definite diagnosis of infection requires microbiological documentation; however, the identification of a specific etiology is frequently missing. In addition, bacterial cultures require at least 24-48 hours for a final result, which is too long for a decision to start antibiotics. Currently, the evaluation of the...

The population-based reference interval is the most widely used tool for interpretation of individual patient laboratory test results. The clinical value of those results depend crucially on the reference intervals with which they are compared, and all efforts directed at ensuring analytically precise and accurate...

Updated with new information from a 2008 article! Health demands that despite quite significant variation in its rate of production, the amount of carbon dioxide in blood is maintained within well-defined narrow limits. The homeostatic mechanisms that maintain the normal content of carbon dioxide in blood are...

All clinical procedures and treatments are associated with potential adverse effects of greater or lesser significance.  The undisputed value of blood testing for both diagnosis and monitoring of disease is tempered by the recognition that repeated blood sampling can result in blood loss of sufficient magnitude to...

The ‘gold standard’ sample for blood gas analysis is arterial blood obtained via an indwelling arterial catheter or by arterial puncture. For a number of reasons capillary blood is an attractive substitute sample that is routinely used in some clinical settings.  The purpose of this article is to examine the evidence ...