Diagnostic accuracy for brachial plexopathy assessed by conventional MRI alone versus conventional MRI combined with DW-MRN was compared by ROC analysis using reference standards.
Most analyses use reference standards.
For analyses of urinary metals, we checked the accuracy of the instrumental methods and the analytical procedure by using reference solutions (standard reference material 12111, normal-range metals urine toxicology control; UTAK Laboratories, Valencia, CA, USA), which were run before every batch of samples.
Standard curves for each cytokine were generated by using reference cytokine concentrations supplied by the manufacturer.
Results were confirmed as negative for IgM antibodies against DENV by using predetermined reference standards.
Six out of the 18 included studies generated more than one set of sensitivity and specificity estimates by using different reference standards in a primary and a secondary analysis.
We compared the rifampicin and isoniazid direct DST results obtained with MODS testing with those obtained by the Peruvian national mycobacteria reference laboratory by using the reference standard, (indirect) proportion method testing, on agar.
By using a reference standard curve provided from the qRT PCR kit, the relative hTERT mRNA expression (with reference to housekeeping gene, porphobilinogen deaminase (PBGD)) was calculated as previously described (Sitaram et al, 2009).
The parameters of resistance, compliance, and impedance are initially estimated based on the patient's age and sex, and can be subsequently refined by using a reference standard measurement of cardiac output.
The laboratory equipment to detect blood lead and cadmium was controlled by using standard reference material from Whole Blood Metals Control (BIO-RAD, USA) for internal quality assurance, and the coefficient of variation for lead and cadmium levels was kept within 10%.
