Defined as one half of the intraindividual percent coefficient. In this study we quantified the variance components when performing coagulation tests with identical analytical platforms in different laboratories and computed.
The smaller the variation between a data set the greater the precision.
Coefficient of variation interpretation laboratory tests. A coefficient of variation cv is a statistical measure of the dispersion of data points in a data series around the mean. It is a standardized unitless measure that allows you to compare variability between disparate groups and characteristics. The cv expresses the variation as a percentage of the mean and is calculated as follows.
A nearly unbiased estimator is. Clia provide values for acceptable analytical variation so called total allowable errors te a that includes the imprecision and bias of a measurement. It turns out that s x is a biased estimator for the population coefficient of variation σ μ.
Regular test randomized answers mean 59 9 44 8 sd 10 2 12 7 for example coefficient of variation interpretation. While the assessment of analytical precision within medical laboratories has received much attention in scientific enquiry the degree of as well as the sources causing variation between them remains incompletely understood. Where n is the sample size.
Cv is used to analyze series of values and is a measurement of precision. Another way to describe the variation of a test is calculate the coefficient of variation or cv. Laboratory test results may influence up to 70 percent of medical decision making.
Usually used in the laboratory to determine if the cv is within a certain standard deviation sd pipette precision taking several pipette readings and determining the variation within the values taken. In the laboratory the cv is preferred when the sd increases in proportion to concentration. The allowable imprecision for laboratory tests has been estimated from criteria based on clinical and analytical test outcome.
The coefficient of variation cv is a relative measure of variability that indicates the size of a standard deviation in relation to its mean. In measures of variability we describe the unitless measure of dispersion called the coefficient of variation. For many laboratory tests external quality assessment programs or government regulations e g.
Research work becomes meaningful and applicable if the tool used is well interpreted with. 9 however one must wonder whether the test results are being interpreted correctly and if not what the impact is of incorrect or inappropriate interpretation on the accuracy of diagnostic decision making based in part on laboratory test results. It is also known as the relative standard deviation rsd.