Passing-Bablok regression for method comparison is a robust, nonparametric method for fitting a straight line to two-dimensional data where both variables, X and Y, are measured with error. It is useful when you have two devices that should give the same measurements and you want to compare them. This is accomplished by test estimate a linear regression line and testing whether the intercept is...

We thank Marin-Franch for his comments on our recent paper. If some aspects of the statistical analysis were not as clear as they perhaps could have been, we are grateful for the opportunity to address them here. The first concern was that our conclusion was in conflict with previous findings. Hood et al. assumed that there is no relationship between retinal nerve fiber layer thickness and visu...

We thank Marin-Franch for his comments on our recent paper. If some aspects of the statistical analysis were not as clear as they perhaps could have been, we are grateful for the opportunity to address them here. The first concern was that our conclusion was in conflict with previous findings. Hood et al. assumed that there is no relationship between retinal nerve fiber layer thickness and visu...

OBJECTIVES To evaluate and validate a hand-held electrochemical meter (Precision Xtra®) as a screening test for subclinical ketosis and hypoglycaemia in lactating dairy cattle. DESIGN Method comparison study using a convenience sample. PROCEDURE Blood samples were collected into plain tubes from the coccygeal vessels of 181 Holstein cows at 2-4 weeks of lactation during summer in Iran. Bloo...

BACKGROUND Busulfan (Bu) requires therapeutic drug monitoring (TDM) in subjects undergoing a conditioning regimen for hematopoietic stem cell transplantation (HSCT). To speed up the procedure and increase reproducibility, we improved our routine LC-MS/MS assay using the on-line solid-phase extraction (SPE) of samples. METHODS A protein precipitation (PP) step was performed before the on-line ...

BACKGROUND Recently, LC-MS/MS was stated to be the method of choice to measure sex steroids. Because information on the mutual agreement of LC-MS/MS methods is scarce, we compared 7 published LC-MS/MS methods for the simultaneous measurement of testosterone, androstenedione, and dehydroepiandrosterone (DHEA). METHODS We used 7 published LC-MS/MS methods to analyze in duplicate 55 random sampl...

We studied the possible effects on serum carbohydrate-deficient transferrin (CDT) determination by a CDTect (Pharmacia) method of serum isolation in four different types of blood-collection tubes, namely: (1) glass tubes (glass Vacutainer tubes with no additive); (2) S-Monovette Neutral tubes (plastic tubes with no additive); (3) S-Monovette Serum tubes (plastic tubes with kaolin-coated plastic...