Because measurements of GFR are tedious, estimated GFRs based on creatinine or cystatin C are widely used for assessing kidney function. Both measured GFRs and the Staging System for CKD based on GFR have analytical and clinical shortcomings. The advantages of serum creatinine and cystatin C, and eGFR will be...

Calculation-based approaches to determining oxygen saturation, as used in some point-of-care tests, increasingly deviate from values measured directly by CO-oximetry as the partial pressure of oxygen in the blood decreases. Oxygen saturation should be measured by CO-oximetry when inaccuracies in calculations may...

Summary The reference interval for a biochemical analyte is usually an interval of values bounded by the reference limit values at certain designated percentiles [1].  As always when choosing a cut-off, the value will determine the trade-off between clinical sensitivity and specificity. When a low cut-off is chosen,...

Reprinted with permission from Biochemia Medica. The journal of Croatian Society of Medical Biochemistry and Laboratory Medicine. Biochemia Medica 2016;26(3):318-36  Blood gas analysis (BGA) is exposed to risks of errors caused by improper sampling, transport and storage conditions. The Clinical and Laboratory...

This article demonstrates that adding a lot of patients without disease and with low test results to a study may improve the ROC curve significantly without any improvement in sensitivity or in positive predictive value of the parameter evaluated. The precision-recall curves are not impacted by the addition of...

Bacterial infections are one of the major reasons for patients presenting to the ED - and the main cause of death in elderly patients. It is important to identify elderly patients with bacterial infections early and initiate treatment in the ED for a better outcome. However, an infection in an elderly patient can be...

For patients presenting to the ED with symptoms of a suspected infection, measuring procalcitonin (PCT) is a useful diagnostic tool to identify bacterial infections, such as sepsis, allowing for early initiation of proper antibiotic treatment. In assessing the severity of sepsis, serum PCT levels are an important...

When a new D-dimer method is evaluated, it’s typically compared to an established D-dimer method using both an analytical and a clinical comparison. Analytical comparisons should be discouraged, as they do not give any useful information about the potential clinical usability of the assay. D-dimer assay comparisons...

Clinical sensitivity, clinical specificity and predictive values are frequently used as performance measure for a biochemistry assay. When D-dimer assay performance is presented, emphasis is often on the negative predictive value (NPV). However, predictive values are greatly influenced by the prevalence of the...

Reprinted from Ann Lab Med 2014 Sep; 34(4):263-73. Procalcitonin (PCT) is used as a biomarker for the diagnosis of sepsis, severe sepsis and septic shock. At the same time, PCT has also been used to guide antibiotic therapy. This review outlines the main indications for PCT measurement and points out possible...